TW201408676A - Composition for forming passivation layer, semiconductor substrate with passivation layer, method for producing semiconductor substrate with passivation layer, photovoltaic cell element, method for producing photovoltaic cell element and photovoltaic - Google Patents

Abstract

A composition for forming a passivation layer, containing a compound represented by Formula (I): M(OR1)m and at least one selected from the group consisting of a fatty acid amide, a polyalkylene glycol compound and an organic filler. In Formula (I), M contains at least one metal element selected from the group consisting of Nb, Ta, V, Y and Hf; R1 independently represents an alkyl group having from 1 to 8 carbon atoms or an aryl group having from 6 to 14 carbon atoms; and m represents an integer of from 1 to 5.

Description

Composition for forming passivation layer, semiconductor substrate with passivation layer, method for producing semiconductor substrate with passivation layer, solar cell element, method for manufacturing solar cell element, and solar cell

The present invention relates to a composition for forming a passivation layer, a semiconductor substrate with a passivation layer, a method for producing a semiconductor substrate with a passivation layer, a solar cell element, a method for producing a solar cell element, and a solar cell.

The manufacturing steps of the conventional tantalum solar cell element will be described.

First, in order to promote the light-blocking effect and achieve high efficiency, a p-type germanium substrate having a textured structure formed on the light-receiving surface side is prepared, followed by a mixed gas atmosphere of phosphorus oxychloride (POCl ₃ ), nitrogen, and oxygen. The treatment was carried out at 800 ° C to 900 ° C for several tens of minutes to uniformly form an n-type diffusion layer. In this conventional method, since phosphorus is diffused by using a mixed gas, an n-type diffusion layer is formed not only on the surface as the light-receiving surface but also on the side surface and the back surface. Therefore, side etching for removing the n-type diffusion layer formed on the side surface is performed. In addition, the n-type diffusion layer formed on the back surface must be converted into a p ⁺ -type diffusion layer. Therefore, an aluminum paste is applied to the entire back surface and heat-treated (calcined), whereby the n-type diffusion layer is converted into a p ⁺ -type diffusion layer, and an aluminum electrode is collectively formed to obtain an ohmic contact.

However, the aluminum electrode formed of the aluminum paste has a low electrical conductivity. Therefore, in order to lower the sheet resistance, the aluminum electrode usually formed on the entire back surface must have a thickness of about 10 μm to 20 μm after heat treatment (calcination). Further, since the thermal expansion coefficients of bismuth and aluminum differ greatly, the ruthenium substrate on which the aluminum electrode is formed generates large internal stresses in the ruthenium substrate during heat treatment (calcination) and cooling, resulting in grain boundary damage and crystal defects growth. And warping.

In order to solve this problem, there is a method of reducing the amount of the aluminum paste applied and making the thickness of the back electrode layer thin. However, when the amount of the aluminum paste applied is reduced, the amount of aluminum diffused from the surface of the p-type germanium semiconductor substrate to the inside becomes insufficient. As a result, there is a problem that the desired back surface field (BSF) effect (the effect of increasing the collection efficiency of the carrier by the presence of the p ⁺ -type diffusion layer) cannot be achieved, so that the characteristics of the solar cell are lowered.

In the above, a point contact method is proposed in which an aluminum paste is applied to a part of the surface of the substrate, and a p ⁺ -type diffusion layer and an aluminum electrode are partially formed (for example, refer to Japanese Patent No. 3107287). .

In the case of such a solar cell having a point contact structure on a surface opposite to the light receiving surface (hereinafter also referred to as "back surface"), it is necessary to suppress the recombination speed of a minority carrier in the surface of a portion other than the aluminum electrode. As the passivation layer for the back surface used for this purpose, an SiO ₂ film or the like has been proposed (for example, refer to Japanese Laid-Open Patent Publication No. 2004-6565). As a passivation effect obtained by forming such an SiO ₂ film, there is an effect that the unbonded bond of the germanium atoms in the surface layer portion of the back surface of the tantalum substrate is lowered, and the surface energy density of the recombination is lowered.

Further, as another method of suppressing recombination of minority carriers, there is a method of reducing the density of minority carriers by an electric field generated by a fixed charge in the passivation layer. Such a passivation effect is generally called an electric field effect, and an aluminum oxide (Al ₂ O ₃ ) film or the like has been proposed as a material having a negative fixed charge (for example, refer to Japanese Patent No. 4767110).

Such a passivation layer is usually formed by an atomic layer deposition (ALD) method or a chemical vapor deposition (CVD) method (for example, refer to the Journal of Applied Physics, 104 (2008), 113703-1~113703-7). Further, as a simple method of forming an aluminum oxide film on a semiconductor substrate, a method using a sol-gel method has been proposed (for example, refer to "Thin Solid Films", 517 (2009), 6327-6330, and "Chinese Physics". Chinese Physics Letters, 26 (2009), 088102-1~088102-4).

The method described in Journal of Applied Physics, 104 (2008), and 113703-1 to 113703-7 includes complicated manufacturing steps such as vapor deposition, and thus it may be difficult to improve productivity. In addition, "Thin Solid Films", 517 (2009), 6327-6330 and "China Physics Letters" (Chinese The composition for forming a passivation layer used in the method described in the methods described in the methods of the above-mentioned methods, such as the method of the method described in the above-mentioned, and the method of the method described in the above-mentioned. . Further, studies on a passivation layer having an excellent passivation effect using an oxide containing a metal element other than aluminum have not been sufficiently performed.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a composition for forming a passivation layer, which can form a passivation layer having a desired shape by a simple method, and has excellent storage stability. Excellent coating uniformity. Further, an object of the present invention is to provide a semiconductor substrate with a passivation layer, a solar cell element, and a solar cell using the composition for forming a passivation layer. Further, an object of the present invention is to provide a semiconductor substrate with a passivation layer and a method for producing a solar cell element using the composition for forming a passivation layer.

The specific means for solving the above problems are as follows.

<1> A composition for forming a passivation layer, comprising a compound represented by the following formula (I) and a group selected from the group consisting of fatty acid decylamine, polyalkylene glycol compound, and organic filler. At least one, M(OR ¹ ) _m (I)

Wherein M contains at least one metal element selected from the group consisting of niobium (Nb), tantalum (Ta), vanadium (V), yttrium (Y), and hafnium (Hf); R ¹ independently represents carbon An alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 14 carbon atoms; and m is an integer of 1 to 5.

<2> The composition for forming a passivation layer according to <1>, further comprising a compound represented by the following formula (II).

In the formula, R ² each independently represents an alkyl group having 1 to 8 carbon atoms; n represents an integer of 0 to 3; and X ² and X ³ each independently represent an oxygen atom or a methylene group; and R ³ , R ⁴ and R ⁵ Each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.

(3) The composition for forming a passivation layer according to the above <1> or <2>, comprising the polyolefin diol compound, wherein the polyolefin diol compound is selected from the group consisting of the following formula (III) At least one of the compounds,

In the formula (III), R ⁶ and R ⁷ each independently represent a hydrogen atom or an alkyl group, R ⁸ represents an alkylene group; n is an integer of 3 or more; and a plurality of R ⁸ may be the same or different.

The composition for forming a passivation layer according to any one of the above-mentioned <1> to <3>, wherein the fatty acid decylamine is contained, and the fatty acid decylamine is selected from the group consisting of the following formula (1). At least one of a group consisting of a compound, a compound represented by the formula (2), a compound represented by the formula (3), and a compound represented by the formula (4), R ⁹ CONH ₂ . . . . (1)

R ⁹ CONH-R ¹⁰ -NHCOR ⁹ . . . . (2)

R ⁹ NHCO-R ¹⁰ -CONHR ⁹ . . . . (3)

R ⁹ CONH-R ¹⁰ -N(R ¹¹ ) ₂ . . . . (4)

In the general formula (1), the general formula (2), the general formula (3), and the general formula (4), R ⁹ and R ¹¹ each independently represent an alkyl group having 1 to 30 carbon atoms or an alkyl group having 2 to 30 carbon atoms. And R ¹⁰ represents an alkylene group having 1 to 10 carbon atoms; and a plurality of R ^{11 's} may be the same or different.

The composition for forming a passivation layer according to any one of the above aspects, comprising the organic filler, wherein the organic filler comprises an acrylic resin, a cellulose resin, and a polystyrene resin. At least one of the group consisting of.

<6> A semiconductor substrate with a passivation layer, comprising: a semiconductor substrate; The heat-treated material of the composition for forming a passivation layer according to any one of the above-mentioned <1> to <5>, wherein the passivation layer is provided on the entire surface or a part of the above-mentioned semiconductor substrate.

<7> A method of producing a semiconductor substrate with a passivation layer, comprising the step of forming a passivation layer according to any one of the above-mentioned items <1> to <5> on the entire surface or a part of the semiconductor substrate. a composition, a step of forming a composition layer; and a step of heat-treating the composition layer to form a passivation layer.

<8> A solar cell element comprising: a semiconductor substrate obtained by pn-bonding a p-type layer and an n-type layer; and a passivation layer provided on the entire surface or a part of the semiconductor substrate, and having the above <1> The heat-treated product of the composition for forming a passivation layer according to any one of the above-mentioned items, wherein the electrode is disposed on one or more layers selected from the group consisting of the p-type layer and the n-type layer.

<9> A method for producing a solar cell element, comprising the steps of: forming a pn junction by bonding a p-type layer and an n-type layer, and selecting a group consisting of the p-type layer and the n-type layer; A composition for forming a passivation layer according to any one of the above items <1> to <5>, wherein one or both surfaces of the surface of the semiconductor substrate having the electrode on the one or more layers of the group are provided. a step of forming a composition layer; The step of heat-treating the above composition layer to form a passivation layer.

<10> A solar cell comprising the solar cell element according to the above <8>, and a wiring material provided on the electrode of the solar cell element.

According to the present invention, it is possible to provide a composition for forming a passivation layer which can form a passivation layer having a desired shape by a simple method, which is excellent in storage stability and excellent in uniformity of a coating film. Further, according to the present invention, it is possible to provide a semiconductor substrate with a passivation layer and a method for producing a semiconductor substrate with a passivation layer having a passivation layer having an excellent passivation effect obtained by using a composition for forming a passivation layer, and having excellent conversion An efficient solar cell element, a method of manufacturing a solar cell element, and a solar cell.

1‧‧‧p-type semiconductor substrate

2‧‧‧n ⁺ type diffusion layer

3, 103, 113‧‧‧ anti-reflection film

4‧‧‧p ⁺ diffusion layer

5‧‧‧Back electrode

6‧‧‧ Passivation layer

7‧‧‧Lighted surface electrode

8‧‧‧Heat treated/aluminum electrode

101, 111‧‧‧矽 substrate

102, 112‧‧‧ diffusion layer

104‧‧‧BSF layer

105, 115‧‧‧ first electrode

106‧‧‧2nd electrode

107‧‧‧passivation film

114‧‧‧p ⁺ layer

116‧‧‧electrode

OA‧‧‧ openings

FIG. 1 is a cross-sectional view schematically showing an example of a method of manufacturing a solar cell element having a passivation layer according to the embodiment.

Fig. 2 is a cross-sectional view schematically showing another example of a method of manufacturing a solar cell element having a passivation layer according to the embodiment.

Fig. 3 is a cross-sectional view schematically showing a back electrode type solar cell element having a passivation layer of the embodiment.

4 is a cross-sectional view showing the structure of a double-sided electrode type solar cell element.

Fig. 5 is a cross-sectional view showing a first configuration example of a solar battery element according to a reference embodiment; Surface map.

Fig. 6 is a cross-sectional view showing a second configuration example of a solar battery element according to the embodiment.

Fig. 7 is a cross-sectional view showing a third configuration example of the solar battery element of the embodiment.

8 is a cross-sectional view showing a fourth configuration example of the solar battery element of the embodiment.

Fig. 9 is a cross-sectional view showing another configuration example of the solar battery element of the reference embodiment.

In the present specification, the term "step" means not only an independent step, but even in the case where it cannot be clearly distinguished from other steps, it is included in the term as long as the purpose of the step can be achieved. In addition, in this specification, the numerical range represented by "~" is a range which contains the numerical value of the before and after "~" as a minimum and maximum. Further, in the present specification, when a plurality of substances corresponding to the respective components are present in the composition in the content of each component in the composition, unless otherwise specified, it means the plurality of substances present in the composition. Total measurement. In addition, in this specification, the term "layer" includes a configuration of a shape formed on a part of the entire surface, in addition to a configuration of a shape formed on the entire surface when viewed in a plan view.

<Composition for forming a passivation layer>

The composition for forming a passivation layer of the present invention contains a compound represented by the following formula (I) (hereinafter also referred to as "the compound of the formula (I)") and a compound selected from the group consisting of fatty acid guanamine and poly At least one of the group consisting of an olefin diol compound and an organic filler (hereinafter also referred to as "specific compound"). The composition for forming a passivation layer may further contain other components as needed.

M(OR ¹ ) _m (I)

In the formula, M contains at least one metal element selected from the group consisting of Nb, Ta, V, Y, and Hf. R ¹ each independently represents an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 14 carbon atoms. m represents an integer from 1 to 5. When m is 2 or more, a plurality of groups represented by R ¹ may be the same or different.

The passivation layer-forming composition containing the above components is applied onto a semiconductor substrate and subjected to heat treatment (calcination), whereby a passivation layer having an excellent passivation effect can be formed into a desired shape. Further, the composition for forming a passivation layer is contained in the compound of the formula (I), and the occurrence of defects such as gelation is suppressed, and the storage stability with time is excellent. Further, the composition for forming a passivation layer is excellent in uniformity of a coating film by containing a specific compound.

Further, the method of using the composition for forming a passivation layer of the present invention is a method which is simple and highly productive without requiring a vapor deposition device or the like. Further, the passivation layer can be formed into a desired shape without complicated steps such as masking treatment.

In the present specification, the passivation effect of the semiconductor substrate can be evaluated by using WT-2000 PVN of Semilab Co., Ltd., WCT-120 of Sinton Instruments, etc. The effective lifetime of a minority carrier in the semiconductor substrate to which the passivation layer is applied is measured by a reflective microwave conduction decay method.

Here, the effective lifetime τ is expressed by the following formula (A) by the bulk lifetime τ _b inside the semiconductor substrate and the surface lifetime τ _{s of the} surface of the semiconductor substrate. When the surface energy density of the surface of the semiconductor substrate is small, τ _s becomes long, and as a result, the effective lifetime τ becomes long. Further, even if defects such as dangling bonds in the semiconductor substrate are reduced, the body life τ _{b is} also long, and the effective life τ is long. That is, the interface characteristics of the passivation layer and the semiconductor substrate and the internal characteristics of the semiconductor substrate such as dangling bonds can be evaluated by measuring the effective lifetime τ.

1/τ=1/τ _b +1/τ _s (A)

In addition, the longer the effective lifetime τ, the slower the recombination speed of a minority carrier. Further, by using a semiconductor substrate having a long effective life to constitute a solar cell element, conversion efficiency is improved.

Further, the storage stability of the composition for forming a passivation layer can be evaluated by the change in viscosity over time. Specifically, it can be evaluated by the following method: the shear viscosity (η ⁰ ) of the composition for forming a passivation layer immediately after preparation (within 12 hours) at 25 ° C and a shear rate of 1.0 s ^-1 The composition for forming a passivation layer after storage for 30 days at 25 ° C was compared at a shear viscosity (η ³⁰ ) at 25 ° C and a shear rate of 1.0 s ^-1 , for example, a change rate of viscosity by time (%) ) to evaluate. The rate of change in viscosity over time (%) is obtained by dividing the absolute value of the difference between the shear viscosity immediately after preparation and the shear viscosity after 30 days by the shear viscosity immediately after preparation, and is specifically calculated by the following formula. The viscosity change rate of the composition for forming a passivation layer is preferably 30% or less, more preferably 20% or less, and still more preferably 10% or less.

Viscosity change rate (%) = | η ^{30 -} η ⁰ | / η ⁰ × 100 (formula)

Further, the coating film uniformity of the composition for forming a passivation layer can be evaluated as follows: When the composition for forming a passivation layer is applied to a semiconductor substrate, whether or not the composition for forming a passivation layer is present in the entire imparting portion on the semiconductor substrate Things.

(compound represented by the formula (I))

The composition for forming a passivation layer contains at least one of the compounds represented by the above formula (I). The compound of formula (I) is a compound known as a metal alkoxide. The compound of the formula (I) is a metal oxide of M in the formula (I) by heat treatment (calcination). By containing the compound of the formula (I) in the composition for forming a passivation layer, a passivation layer having an excellent passivation effect can be formed. Regarding the reason, it can be considered as follows.

It is considered that the oxide formed by heat-treating (calcining) the composition for forming a passivation layer containing the compound of the formula (I) is likely to be in an amorphous state, causing defects of metal atoms or the like and having a vicinity of the interface with the semiconductor substrate. Fixed charge. It is considered that the negative fixed charge generates an electric field in the vicinity of the interface of the semiconductor substrate, whereby the concentration of the minority carrier can be lowered, and as a result, the carrier recombination speed at the interface is suppressed, so that an excellent passivation effect is exhibited.

In addition, the fixed charge of the passivation layer can be evaluated by Capacitance Voltage Measurement (CV). Among them, the surface energy density of the passivation layer formed of the composition for forming a passivation layer of the present invention may be a larger value than the case of the metal oxide layer formed by the AID method or the CVD method. However, the passivation layer formed of the composition for forming a passivation layer of the present invention has a large electric field effect and a small concentration of carriers, and the surface life τ _s becomes long. Therefore, the surface energy density is relatively unproblematic.

In the formula (I), M contains at least one metal element selected from the group consisting of Nb, Ta, V, Y and Hf. Among them, from the viewpoint of the fixed charge and the passivation effect, M preferably contains at least one metal element selected from the group consisting of Nb, Ta, and Y, and more preferably contains Nb. Further, from the viewpoint of making the fixed charge density of the passivation layer negative, M preferably contains at least one metal element selected from the group consisting of Nb, Ta, V, and Hf, and more preferably contains Nb selected from At least one of a group consisting of Ta, VO, and Hf.

In the formula (I), R ¹ each independently represents an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 14 carbon atoms. When R ^{1 is} present in a plurality of cases, R ¹ may be the same or different. . R ^{1 is} preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms.

The alkyl group represented by R ¹ may be linear or branched. Specific examples of the alkyl group represented by R ¹ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a second butyl group, a tert-butyl group, a hexyl group, an octyl group, and a 2-ethyl group. Heji and so on.

Specific examples of the aryl group represented by R ¹ include a phenyl group.

The alkyl group and the aryl group represented by R ¹ may have a substituent. The substituent of the alkyl group may, for example, be a halogen atom, an amine group, a hydroxyl group, a carboxyl group, a thiol group or a nitro group. The substituent of the aryl group may, for example, be a halogen atom, a methyl group, an ethyl group, an isopropyl group, an amine group, a hydroxyl group, a carboxyl group, a decyl group or a nitro group.

Among them, from the viewpoint of storage stability and passivation effect, R ^{1 is} preferably an unsubstituted alkyl group having 1 to 8 carbon atoms, more preferably an unsubstituted alkyl group having 1 to 4 carbon atoms.

In the formula (I), m represents an integer of 1 to 5. Here, it is stable From a qualitative point of view, m is preferably 5 when M is Nb, preferably 5 when M is Ta, and preferably 3 when M is VO, and Y is Y when M is VO. In the case where m is preferably 3, m is preferably 4 when M is Hf.

The compound represented by the formula (I) is preferably selected from the group consisting of compounds having an alkyl group in which m is 1 to 5 and R ^{1 is} independently an alkyl group having 1 to 4 carbon atoms, from the viewpoints of storage stability and passivation. At least one of the group is more preferably at least one selected from the group consisting of compounds having an unsubstituted alkyl group in which m is 1 to 5 and R ¹ is a carbon number of 1 to 4.

Examples of the compound represented by the formula (I) include hydrazine hydride, hydrazine ethoxide, hydrazine isopropoxide, hydrazine n-propoxide, hydrazine n-butoxide, hydrazine tert-butoxide, hydrazine isobutoxide, hydrazine hydride, hydrazine ethoxide, Barium isopropoxide, barium n-propoxide, barium n-butoxide, barium tert-butoxide, barium isobutoxide, barium methoxide, barium ethoxide, barium isopropoxide, barium n-propoxide, barium n-butoxide, third Alcohol, isobutanol, vanadium oxide, vanadium oxide, vanadium isopropoxide, vanadium n-propoxide, vanadium n-butoxide, vanadium tributoxide, vanadium isobutoxide, methanol, ethanol铪, bismuth isopropoxide, ruthenium n-propoxide, ruthenium n-butoxide, hydrazine tert-butoxide, hydrazine isobutoxide, etc., preferably ruthenium ethoxide, ruthenium n-butoxide, hydrazine ethoxide, ruthenium n-butoxide, ethanol oxidation Vanadium, ethanol hydrazine and ethanol hydrazine. From the viewpoint of obtaining a negative fixed charge density, ethanol ruthenium, ruthenium n-propoxide, ruthenium n-butoxide, ruthenium ethoxide, ruthenium n-propoxide, ruthenium n-butoxide, vanadium oxide, and vanadium oxide of n-propanol are preferred. , n-butanol oxide vanadium, ethanol oxime, n-propanol oxime and n-butanol oxime.

Further, as the compound represented by the formula (I), a product can be used, and a commercially available product can also be used. Commercial products include, for example, the High Purity Chemical Research Institute Co., Ltd. Bismuth methoxy quinone, pentaethoxy hydrazine, pentaisopropoxy hydrazine, penta-n-propoxy hydrazine, penta-isobutoxy fluorene, penta-n-butoxy fluorene, penta-second butoxy fluorene , pentamethoxy hydrazine, pentaethoxy hydrazine, pentaisopropoxy fluorene, penta-n-propoxy fluorene, penta-isobutoxy fluorene, penta-n-butoxy fluorene, penta-butoxy fluorene, Penta-t-butoxide, vanadium oxide (V), triethoxy vanadium (V), triisopropoxide, vanadium (V), tri-n-propanol, vanadium (V), triisobutyl Alcohol oxide vanadium (V), tri-n-butanol vanadium oxide (V), tri-second butanol vanadium oxide (V), tri-tert-butanol vanadium oxide (V), triisopropoxy ruthenium, tri-negative Butoxy oxime, tetramethoxy ruthenium, tetraethoxy ruthenium, tetraisopropoxy oxy group, tetra-t-butoxy ruthenium; pentaethoxy ruthenium, pentaethoxy group of Beixing Chemical Industry Co., Ltd. Bismuth, pentabutoxy fluorene, n-butanol oxime, t-butanol oxime; Nichia oxytriethanol vanadium, oxytri-n-propanol vanadium, oxytri-n-butanol vanadium, oxygen Vascular triisobutanol vanadium, oxy tri-second butanol vanadium, and the like.

In the preparation of the compound represented by the formula (I), a known method such as reacting a halide of a specific metal (M) with an alcohol in the presence of an inert organic solvent, and thereby capturing a halogen can be used. A method of adding an ammonia or an amine compound (Japanese Patent Laid-Open Publication No. SHO-63-227593 and Japanese Patent Laid-Open No. Hei No. 3-291247).

The compound represented by the formula (I) can also be used as a compound having a chelate structure by mixing with a compound having a specific structure of two carbonyl groups. The compound formed with the chelating structure is a compound having at least a portion of the alkoxide group of the compound of formula (I) substituted with a compound of a specific structure to form a chelate structure. At this time, a liquid medium may be present as needed, and heat treatment, addition of a catalyst, or the like may be performed. Alkoxide salt At least a part of the structure is replaced by a chelate structure, and the stability of the compound of the formula (I) for hydrolysis and polymerization is improved, and the storage stability of the composition for forming a passivation layer containing the composition is further improved.

From the viewpoint of storage stability, the compound having a specific structure of two carbonyl groups is preferably at least one selected from the group consisting of a β-diketone compound, a β-ketoester compound, and a malonic acid diester.

Specific examples of the β-diketone compound include acetamidineacetone, 3-methyl-2,4-pentanedione, 2,3-pentanedione, 3-ethyl-2,4-pentanedione, and 3-butyl Base-2,4-pentanedione, 2,2,6,6-tetramethyl-3,5-heptanedione, 2,6-dimethyl-3,5-heptanedione, 6-methyl -2,4-heptanedione and the like.

Specific examples of the β-ketoester compound include methyl ethyl acetate, ethyl acetate, ethyl acetoacetate, isopropyl acetate, isobutyl acetate, butyl acetate, and acetic acid. Third butyl ester, amyl acetate, isoamyl acetate, hexyl acetate, n-octyl acetate, heptyl acetate, 3-pentyl acetate, 2-ethyl fluorenyl Ethyl heptanoate, ethyl 2-methylacetate, ethyl 2-butylacetate, ethyl hexylacetate, ethyl 4,4-dimethyl-3-oxopentanoate, 4 -ethyl methyl-3-oxopentanoate, ethyl 2-ethylacetate, methyl 4-methyl-3-oxopentanoate, ethyl 3-oxohexanoate, 3-oxo Ethyl valerate, methyl 3-oxopentanoate, methyl 3-oxohexanoate, ethyl 3-oxoheptanoate, methyl 3-oxoheptanoate, 4,4-dimethyl-3 - Methyl oxovalerate and the like.

Specific examples of the malonic acid diester include dimethyl malonate, diethyl malonate, dipropyl malonate, diisopropyl malonate, dibutyl malonate, and malonic acid di- Third butyl ester, dihexyl malonate, tert-butyl malonate, methylmalonic acid Ethyl ester, diethyl ethylmalonate, diethyl isopropylmalonate, diethyl butyl malonate, diethyl second butyl malonate, diethyl isobutyl malonate Ester, diethyl 1-methylbutylmalonate, and the like.

When the compound of the formula (I) has a chelate structure, the number of the chelate structures is not particularly limited as long as it is from 1 to 5. The number of carbonyl groups contributing to the chelating structure is not particularly limited. In the case where M is Nb, it is preferred that the number of carbonyl groups contributing to the chelating structure is 1 to 5'. When M is Ta, it is preferred to be helpful. The number of carbonyl groups in the chelating structure is 1 to 5, and in the case where M is VO, the number of carbonyl groups contributing to the chelating structure is preferably 1 to 3. In the case where M is Y, it is preferable to contribute to the chelation. The number of carbonyl groups in the structure is from 1 to 3. When M is Hf, the number of carbonyl groups contributing to the chelating structure is preferably from 1 to 4.

The number of chelating structures can be controlled, for example, by appropriately adjusting the ratio of mixing the compound of the formula (I) with a compound which can form a chelate with a metal element. Further, a compound having a desired structure may be appropriately selected from commercially available metal chelate compounds.

The presence of the chelating structure in the compound of formula (I) can be confirmed by the analytical methods generally used. For example, it can be confirmed using an infrared spectroscopic spectrum, a nuclear magnetic resonance spectrum, or a melting point.

The state of the compound of formula (I) may be liquid or solid. The compound represented by the formula (I) is preferably at room temperature from the viewpoint of the storage stability of the composition for forming a passivation layer and the mixing property in the case of using the compound represented by the following formula (II). Liquid at 25 ° C). When the compound of the formula (I) is a solid, the passivation effect of the passivation layer formed and the storage of the composition for forming a passivation layer are stable. From the viewpoint of the nature and the like, a compound which is excellent in solubility or dispersibility in a solvent is preferable, and a compound which is stable when it is a solution or a dispersion is preferable.

The content of the compound of the formula (I) contained in the composition for forming a passivation layer can be appropriately selected as needed. The content of the compound of the formula (I) can be set to 0.1% by mass to 80% by mass, preferably 3% by mass to 70% by mass, based on the storage stability and the passivation effect. More preferably, it is 5% by mass to 60% by mass, and further preferably 10% by mass to 50% by mass.

(compound represented by the formula (II))

The composition for forming a passivation layer of the present invention preferably further contains at least one of a compound represented by the following formula (II) (hereinafter sometimes referred to as "specific organoaluminum compound").

In the formula, R ² each independently represents an alkyl group having 1 to 8 carbon atoms. n represents an integer from 0 to 3. X ² and X ³ each independently represent an oxygen atom or a methylene group. R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.

The specific organoaluminum compound contains a compound called aluminum alkoxide, chelating aluminum or the like, and preferably has a chelate aluminum structure in addition to the aluminum alkoxide structure. In addition, as described in the Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi, vol. 97, pp 369-399 (1989), the organoaluminum compound is alumina (Al ₂ O ₃ by heat treatment (calcination)). ). At this time, the formed alumina tends to be in an amorphous state, so that a larger negative fixed charge can be obtained. As a result, it is considered that a passivation layer having an excellent passivation effect can be formed.

In addition to the above, it is considered that by combining the compound represented by the formula (I) with the compound represented by the formula (II), the passivation effect is further improved by the respective effects in the passivation layer. Further, it is considered that the metal (M) represented by the general formula (I) and the aluminum are heat-treated (calcined) in a state in which the compound represented by the general formula (I) and the compound represented by the general formula (II) are coexisted. The physical properties such as the reactivity of the composite metal alkoxide and the vapor pressure of (Al) are improved, and the denseness of the passivation layer as a heat-treated product (calcined product) is improved, and as a result, the passivation effect is further improved.

In the formula (II), R ² each independently represents an alkyl group having 1 to 8 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms. The alkyl group represented by R ² may be linear or branched. Specific examples of the alkyl group represented by R ² include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a second butyl group, a tert-butyl group, a hexyl group, an octyl group, and a 2-ethyl group. Heji and so on. In view of the storage stability and the passivation effect, the alkyl group represented by R ² is preferably an unsubstituted alkyl group having 1 to 8 carbon atoms, more preferably an unsubstituted carbon group having 1 to 4 carbon atoms. alkyl.

In the formula (II), n represents an integer of 0 to 3. From the viewpoint of storage stability, n is preferably an integer of 1 to 3, more preferably 1 or 3. Further, X ² and X ³ each independently represent an oxygen atom or a methylene group. From the viewpoint of storage stability, at least one of X ² and X ³ is preferably an oxygen atom.

R ³ , R ⁴ and R ⁵ in the formula (II) each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. The alkyl group represented by R ³ , R ⁴ and R ⁵ may be linear or branched. The alkyl group represented by R ³ , R ⁴ and R ⁵ may have a substituent or may be unsubstituted, and is preferably unsubstituted. The alkyl group represented by R ³ , R ⁴ and R ⁵ is an alkyl group having 1 to 8 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms. Specific examples of the alkyl group represented by R ³ , R ⁴ and R ⁵ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a second butyl group, a tert-butyl group, a hexyl group, and a octyl group. Base, ethylhexyl and the like.

In view of the storage stability and the passivation effect, R ³ and R ⁴ in the formula (II) are preferably independently a hydrogen atom or an unsubstituted alkyl group having 1 to 8 carbon atoms, more preferably Preferably, it is a hydrogen atom or an unsubstituted alkyl group having 1 to 4 carbon atoms.

Further, R ⁵ in the formula (II) is preferably a hydrogen atom or an unsubstituted alkyl group having 1 to 8 carbon atoms, more preferably a hydrogen atom or a carbon number, from the viewpoint of storage stability and passivation effect. 1 to 4 unsubstituted alkyl groups.

From the viewpoint of storage stability, the compound represented by the formula (II) is preferably a compound wherein n is 1 to 3 and R ^{5 is} independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

The compound represented by the formula (II) is preferably at least one selected from the group consisting of: n is 0, and R ^{2 is} independently a carbon number from the viewpoint of storage stability and passivation effect. a compound of 1 to 4 alkyl groups; and n is 1 to 3, R ^{2 is} independently an alkyl group having 1 to 4 carbon atoms, at least one of X ² and X ³ is an oxygen atom, and R ³ and R ⁴ are each independently The ground is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ^{5 is} each independently a hydrogen atom or a compound having an alkyl group having 1 to 4 carbon atoms.

More preferably, the compound represented by the formula (II) is at least one selected from the group consisting of: n is 0, and R ^{2 is} independently an unsubstituted alkyl group having 1 to 4 carbon atoms; a compound; and n is 1 to 3, and R ^{2 is} independently an unsubstituted alkyl group having 1 to 4 carbon atoms; at least one of X ² and X ³ is an oxygen atom, and R ³ bonded to the above oxygen atom or R ⁴ is an alkyl group having 1 to 4 carbon atoms, and when X ² or X ³ is a methylene group, a compound in which R ³ or R ⁴ of the above methylene group is a hydrogen atom and R ⁵ is a hydrogen atom .

Specific examples of the specific organoaluminum compound (trialkoxide aluminum) wherein n is 0 in the formula (II) include trimethoxy aluminum, triethoxy aluminum, triisopropoxy aluminum, and tri-second butoxy group. Aluminum, mono-t-butoxy-diisopropoxy aluminum, tri-t-butoxide aluminum, tri-n-butoxy aluminum, and the like.

Further, specific examples of the specific organoaluminum compound in which n is from 1 to 3 in the general formula (II) include ethyl acetoacetic acid aluminum diisopropylate [(ethyl acetoacetate) aluminum isopropoxide], and tris(ethyl) Ethyleneacetate) aluminum and the like.

Further, as the specific organoaluminum compound in which n is 1 to 3 in the formula (II), a product can be used, and a commercially available product can also be used. Commercially available products include, for example, trade names ALCH, ALCH-50F, ALCH-75, ALCH-TR, and ALCH-TR-20 of Kawasaki Seika Co., Ltd.

The specific organoaluminum compound of the formula (II) wherein n is 1 to 3 can be produced by mixing a trialkoxyaluminum with the above-mentioned compound having a specific structure of two carbonyl groups.

When a trialkoxyaluminum is mixed with a compound having a specific structure of two carbonyl groups, at least a part of the alkoxide group of the trialkoxyaluminum is replaced with a compound having a specific structure to form a chelate aluminum structure. At this time, a liquid medium may be present as needed, and heat treatment, addition of a catalyst, or the like may be performed. By replacing at least a part of the aluminum alkoxide structure with a chelate aluminum structure, the stability of the specific organoaluminum compound to hydrolysis and polymerization is improved, and the storage stability of the composition for forming a passivation layer containing the same is further improved.

The compound having a specific structure of two carbonyl groups may, for example, be a β-diketone compound, a β-ketoester compound or a malonic acid diester. From the viewpoint of storage stability, it is preferably selected from β-diketone. At least one of a group consisting of a compound, a β-ketoester compound, and a malonic acid diester.

In the case where the specific organoaluminum compound has a chelate aluminum structure, there is no particular limitation as long as the number of the chelate aluminum structures is from 1 to 3. Among them, from the viewpoint of storage stability, it is preferably 1 or 3, and more preferably 1 in terms of solubility. The number of the chelate aluminum structure can be controlled, for example, by appropriately adjusting the ratio of mixing the trialkoxy aluminum with the compound having a specific structure of two carbonyl groups. Further, a compound having a desired structure may be appropriately selected from commercially available chelate aluminum compounds.

In the compound represented by the formula (II), in terms of the passivation effect and the compatibility with a solvent contained as necessary, specifically, it is preferably selected from the group consisting of At least one of the group consisting of ethyl acetoacetic acid aluminum diisopropylate and aluminum triisopropoxide is more preferably ethyl acetoacetate aluminum diisopropylate.

The presence of the aluminum chelate structure in the specific organoaluminum compound can be confirmed by an analysis method generally used, for example, by using infrared spectroscopic spectrum, nuclear magnetic resonance spectrum or melting point.

The specific organoaluminum compound may be in the form of a liquid or a solid, and is not particularly limited. From the viewpoint of the passivation effect and storage stability, it is preferably a specific organoaluminum compound which is stable at normal temperature (25 ° C) and has good solubility or dispersibility, and is preferably used as a solution or dispersion. Stable specific organoaluminum compounds. By using such a specific organoaluminum compound, the homogeneity of the formed passivation layer is further improved, and the tendency of the desired passivation effect can be stably obtained.

When the composition for forming a passivation layer contains a specific organoaluminum compound, the content of the specific organoaluminum compound is not particularly limited. In the case where the total content of the compound of the formula (I) and the specific organoaluminum compound is 100% by mass, the content of the specific organoaluminum compound is preferably 0.5% by mass or more and 80% by mass or less, more preferably 1% by mass. % or more and 75% by mass or less, more preferably 2% by mass or more and 70% by mass or less, and particularly preferably 3% by mass or more and 70% by mass or less.

When the content of the specific organoaluminum compound is set to 0.5% by mass or more, the storage stability of the composition for forming a passivation layer tends to be improved. In addition, when the content ratio of the specific organoaluminum compound is 80% by mass or less, the passivation effect tends to be improved.

In the case where the composition for forming a passivation layer contains a specific organoaluminum compound The content of the specific organoaluminum compound in the composition for forming a passivation layer may be appropriately selected as needed. For example, the content of the specific organoaluminum compound can be set to 1% by mass to 70% by mass, preferably 3% by mass to 60% by mass in the composition for forming a passivation layer, from the viewpoint of storage stability and passivation effect. More preferably, it is 5 mass% - 50 mass%, and further preferably 10 mass% - 30 mass%.

(specific compound)

The composition for forming a passivation layer of the present invention contains at least one selected from the group consisting of a fatty acid decylamine, a polyolefin diol compound, and an organic filler (specific compound). When the composition for forming a passivation layer of the present invention containing a specific compound is applied to a semiconductor substrate, the viscosity is lowered, and the viscosity is increased. Therefore, the passivation layer forming composition of the present invention can form a passivation layer of a desired shape by a simple method.

In addition, the composition layer of the coating film which is a composition for forming a passivation layer tends to be more uniform by containing a specific compound. The reason for this is that when the composition for forming a passivation layer is applied to the semiconductor substrate, the viscosity of the composition for forming a passivation layer is lowered, whereby the entrapment of the bubbles is suppressed.

The content of the specific compound contained in the composition for forming a passivation layer can be appropriately selected as needed. For example, the content of the specific compound in the composition for forming a passivation layer can be set to 0.01% by mass to 70% by mass, preferably 0.01% by mass to 60% by mass, more preferably, from the viewpoint of the printability and the passivation effect. It is 0.01% by mass to 50% by mass.

[Polyolefin diol compound]

The polyolefin diol compound of the present invention may be liquid or solid, and is not particularly limit. From the viewpoint of the passivation effect and the printability, a polyolefin diol compound having good stability at normal temperature (25 ° C) and good solubility or dispersibility is preferable. By using such a polyolefin diol compound, the uniformity of the formed passivation layer is further improved, and the desired passivation effect tends to be stably obtained.

The polyolefin diol compound preferably contains at least one selected from the group consisting of compounds represented by the following formula (III).

In the formula (III), R ⁶ and R ⁷ each independently represent a hydrogen atom or an alkyl group, and R ⁸ represents an alkylene group. n is an arbitrary integer of 3 or more. In addition, a plurality of R ⁸ may be the same or different.

In the formula (III), n represents an integer of 3 or more. From the viewpoint of printability, n is preferably from 5 to 23,000, more preferably from 10 to 11,000, and still more preferably from 20 to 2,300. When n is 3 or more, the content of the compound represented by the formula (III) in the composition for forming a passivation layer is easily suppressed, and the viscosity tends to be suitable for printing. In addition, when n is 23,000 or less, the viscosity of the composition for forming a passivation layer tends to be excessively high.

R ⁶ and R ⁷ in the formula (III) each independently represent a hydrogen atom or an alkyl group. The alkyl group represented by R ⁶ and R ⁷ preferably has a carbon number of 1 to 10, more preferably 1 to 5, and still more preferably 1 or 2.

Specifically, R ⁶ and R ⁷ are each independently independently a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a second butyl group, a tert-butyl group, a hexyl group, An octyl group, an ethylhexyl group or the like, more preferably a hydrogen atom, a methyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a second butyl group or a tert-butyl group, and further preferably a hydrogen atom, a methyl group or Ethyl.

R ⁸ in the formula (III) represents an alkylene group. The alkylene group represented by R ⁸ preferably has a carbon number of 1 to 20, more preferably 1 to 10, and still more preferably 1 to 3.

Specifically, R ^{8 is} preferably an ethyl group, a propyl group, a hexyl group, an octyl group, a decyl group or a hexadecyl group, more preferably an ethyl group, a propyl group, a hexyl group or a hexyl group. The base is further preferably an ethyl or a propyl group.

Specific examples of the compound represented by the formula (III) include polyethylene glycol, polypropylene glycol, polyethylene glycol monomethyl ether, and poly(ethylene glycol-propylene glycol) copolymer. Among these compounds, polyethylene glycol is preferred. By using polyethylene glycol, the printability of the composition for forming a passivation layer tends to be improved, and polyethylene glycol is also easily obtained.

The compound represented by the formula (III) may be used singly or in combination of two or more compounds represented by the formula (III) having different structures. Further, the compound represented by the formula (III) can also be used after being copolymerized with other specific compounds.

When two or more compounds represented by the formula (III) having different structures are used in combination, the combination thereof may be exemplified by a combination of polyethylene glycol and polypropylene glycol, polyethylene glycol and polyethylene glycol monomethyl ether. Combination, etc.

The compound represented by the formula (III) may be in the form of a liquid or a solid. From the viewpoint of the passivation effect of the formed passivation layer and the printability of the composition for forming a passivation layer When the compound represented by the formula (III) is a solid, it is preferably a compound which is excellent in solubility or dispersibility in a solvent at normal temperature (25 ° C), and is preferably prepared into a solution or A compound that is stable at the time of dispersion. In the case of such a compound, the homogeneity of the formed passivation layer is further improved, and the desired passivation effect can be stably obtained.

When the compound represented by the formula (III) has a glass transition temperature, the glass transition temperature is not particularly limited, and is preferably in the range of -100 ° C to 100 ° C, more preferably in the range of -50 ° C to 25 ° C. .

Further, in the present invention, the glass transition temperature of the compound represented by the general formula (III) can be measured by the following method: differential scanning calorimetry (DSC) curve measured by using a differential thermal analyzer. Inflection point for research.

When the compound represented by the formula (III) has a melting point, the melting point thereof is not particularly limited, but is preferably in the range of from 20 ° C to 200 ° C, more preferably in the range of from 40 ° C to 100 ° C.

Further, in the present invention, the melting point of the compound represented by the formula (III) can be measured by investigating the melting peak measured by using a differential thermal analyzer.

The number average molecular weight of the compound represented by the formula (III) is preferably from 1,000 to 5,000,000, more preferably from 2,000 to 5,000,000. When the number average molecular weight is 1000 or more, the functionality as a thixotropic agent is sufficiently exhibited, and when the number average molecular weight is 5,000,000 or less, the viscosity of the composition for forming a passivation layer can be suppressed from becoming excessive. High, so the printability is better. In addition, when the number average molecular weight is 2,000 or more, the printability tends to be better.

The number average molecular weight can be determined using Gel Permeation Chromatography (GPC method). Further, the measurement conditions of the number average molecular weight of the GPC method are as follows, for example.

Measuring device: Shodex GPC SYSTEM-11 (Showa Denko Co., Ltd.)

Dissolution: CF3COONa 5mmol/hexafluoroisopropanol (HFIP) (1L)

Column: sample column HFIP-800P HFIP-80M × 2, reference column HFIP-800R × 2

Column temperature: 40 ° C

Flow rate: 1.0ml/min

Detector: Shodex Refractive Index (RI) STD: PMMA (Shodex Standard (STANDARD) M-75)

[fatty acid amide]

The fatty acid guanamine preferably contains a compound represented by the following formula (1), a compound represented by the formula (2), a compound represented by the formula (3), and a compound represented by the formula (4). At least one of the group consisting of. Further, the fatty acid guanamine may be used alone or in combination of two or more.

R ⁹ CONH ₂ . . . . (1)

R ⁹ CONH-R ¹⁰ -NHCOR ⁹ . . . . (2)

R ⁹ NHCO-R ¹⁰ -CONHR ⁹ . . . . (3)

R ⁹ CONH-R ¹⁰ -N(R ¹¹ ) ₂ . . . . (4)

In the general formula (1), the general formula (2), the general formula (3), and the general formula (4), R ⁹ and R ¹¹ each independently represent an alkyl group having 1 to 30 carbon atoms or an alkyl group having 2 to 30 carbon atoms. And R ¹⁰ represents an alkylene group having 1 to 10 carbon atoms. A plurality of R ^{11 's} may be the same or different.

In the general formula (1), the general formula (2), the general formula (3), and the general formula (4), the alkyl groups represented by R ⁹ and R ^l1 are each independently a carbon number of 1 to 30, and are printed and passivated. From the viewpoint of the effect, it is preferably from 1 to 25 carbon atoms, more preferably from 1 to 20 carbon atoms.

In the general formula (1), the general formula (2), the general formula (3), and the general formula (4), the alkenyl groups represented by R ⁹ and R ¹¹ are each independently a carbon number of 2 to 30, and are printed and passivated. From the viewpoint of the effect, it is preferably 2 to 25 carbon atoms, more preferably 2 to 20 carbon atoms.

The alkyl group and the alkenyl group represented by R ⁹ and R ¹¹ may each independently be linear, branched or cyclic, and are preferably linear or branched.

Further, the alkyl group and the alkenyl group represented by R ⁹ and R ¹¹ may be unsubstituted or may have a substituent. Examples of such a substituent include a hydroxyl group, a chlorine group, a bromine group, a fluorine group, an aldehyde group, a carbonyl group, a nitro group, an amine group, a sulfonic acid group, an alkoxy group, a decyloxy group and the like.

Specific examples of the alkyl group and the alkenyl group represented by R ⁹ and R ¹¹ include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, an isobutyl group, a decyl group, a dodecyl group, and an octadecyl group. Hexadecenyl, behenyl, and the like.

The alkyl group and the alkenyl group represented by R ⁹ are each independently preferably a carbon number of 5 to 25, more preferably a carbon number of 10 to 20, and still more preferably a carbon number of 15 to 18.

The alkyl groups represented by R ¹¹ are each independently preferably a carbon number of 1 to 10, more preferably a carbon number of 1 to 6, and more preferably a carbon number of 1 to 3. The alkenyl group represented by R ¹¹ is independently preferably a carbon number of 2 to 10, more preferably a carbon number of 2 to 6, and further preferably a carbon number of 2 to 3.

Further, R ^{9 is} preferably an alkyl group having 1 to 30 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, further preferably an alkyl group having 1 to 6 carbon atoms, particularly preferably an alkyl group having 1 to 3 carbon atoms. base.

In the general formula (2), the general formula (3), and the general formula (4), the alkylene groups represented by R ¹⁰ are each independently a carbon number of 2 to 10, and from the viewpoint of printability and passivation effect, it is preferred. It has a carbon number of 2 to 8, more preferably a carbon number of 2 to 6, and preferably a carbon number of 2 to 4. The alkylene group represented by R ¹⁹ may be linear or branched. Specific examples of the alkylene group represented by R ⁸ include an exoethyl group, a propyl group, a butyl group, and a octyl group.

Specific examples of the fatty acid monodecylamine represented by the formula (1) include decyl laurate, decyl palmitate, decylamine stearate, decyl oleate, and decyl erucamide.

Further, specific examples of the N-substituted fatty acid decylamine represented by the formula (2) include N,N'-extended ethyl bislaurate decylamine and N,N'-methylenebisstearate decylamine. , N, N'-extended ethyl bis-stearate decylamine, N, N'-extended ethyl bis-oleic acid decylamine, N, N'-extended ethyl bis-decanoic acid decylamine, N, N'- Ethyl bis- 12-hydroxystearic acid decylamine, N,N'-butyl-butyl bis-stearate, amide, N,N'-hexamethylenebisstearate, N,N'- Hexamethylene bis-oleic acid decylamine, N, N'-extended xylylene bis-stearate decylamine and the like.

Further, specific examples of the N-substituted fatty acid decylamine represented by the formula (3) include N,N'-dioleyl adipic acid decylamine and N,N'-distearoyl adipate. Amine, N,N'-dioleyl sebacate, N,N'-distearoyl sebacate, N,N'-distearate decylamine, N, N'-distearylisophthalic acid decylamine and the like.

Further, specific examples of the N-substituted fatty acid guanamine represented by the general formula (4) Examples thereof include dimethylaminopropyl decylamine stearate, diethylaminoethyl decylamine stearate, dimethylaminopropyl decyl laurate, and dimethylaminol myristate. Propyl decylamine, dimethylaminopropyl decylamine palmitate, dimethylaminopropyl decylamine stearate, dimethylaminopropyl decyl amide, dimethylamino oleate Propyl decylamine, dimethylaminopropyl decylamine isostearate, dimethylaminopropyl decyl linolenate, dimethylaminopropyl decyl ricinoleate, hydroxystearic acid Dimethylaminopropyl decylamine, N,N-dihydroxymethylaminopropyl decylamine stearate, diethylaminoethyl guanamine laurate, diethylaminoethyl myristate Indoleamine, diethylaminoethyl palmitate palmitate, diethylaminoethylguanamine stearate, diethylaminoethylguanamine behenate, diethylaminoethyl oleate Indoleamine, linolenic acid diethylaminoethylguanamine, ricinoleic acid diethylaminoethylguanamine, isostearic acid diethylaminoethylguanamine, hydroxystearic acid diethyl Aminoethyl decylamine, N,N-dihydroxyethylaminoethyl decylamine Diethylaminopropyl laurate laurate, diethylaminopropyl decyl myristate, diethylaminopropyl decyl palmitate, diethylaminopropyl decylamine stearate, Diethylaminopropyl decyl amide, diethylaminopropyl decyl oleate, diethylaminopropyl linoleic acid, diethylaminopropyl ricinoleate Amine, diethylaminopropyl hydroxy myristate, diethylaminopropyl hydroxystearate, N,N-dihydroxyethylaminopropyl decylamine and the like.

Among these fatty acid decylamines, from the viewpoint of solubility in a dispersion medium, it is preferred to use a decylamine selected from the group consisting of decylamine stearate, N,N'-methylenebisstearate, and stearic acid. At least one of the group consisting of dimethylaminopropyl decylamine.

The fatty acid guanamine may be in the form of a liquid or a solid. Passivation effect and printability In the case where the fatty acid decylamine is a solid, it is preferably a compound which is excellent in solubility or dispersibility in a solvent at normal temperature (25 ° C), and is preferably stable in a solution or a dispersion. compound of. In the case of such a compound, the homogeneity of the formed passivation layer is further improved, and the desired passivation effect can be stably obtained.

The fatty acid guanamine is desirably distilled or decomposed at 30 ° C to 400 ° C, more preferably at 40 ° C to 300 ° C for evapotranspiration or decomposition, and further preferably evapotranspiration or decomposition at temperatures below 50 ° C to 250 ° C. When the fatty acid guanamine is evaporated or dispersed at 400 ° C or lower, it does not hinder the formation of the passivation layer, which is preferable.

In the case where at least one selected from the group consisting of a polyolefin diol compound and a fatty acid decylamine is used as the specific compound, a suitable compound is preferable from the viewpoints of printability and solubility in a dispersion medium. It is at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, decylamine stearate, decyl N,N'-methylenebisstearate, and dimethylaminopropyl decylamine stearate. It is preferred to use at least one selected from the group consisting of polyethylene glycol and decylamine stearate.

[Organic filler]

The organic filler is preferably a particle or a fiber containing an organic compound. The material of the organic filler may be exemplified by urea fumarin resin, phenol resin, polycarbonate resin, melamine resin, epoxy resin, unsaturated polyester resin, fluorenone resin, polyurethane resin, polyolefin resin, acrylic acid. Resin, fluororesin, polystyrene resin, cellulose resin, formaldehyde resin, benzofuran-indene resin, lignin resin, petroleum resin, amine resin, polyester resin, polyether oxime resin, butadiene resin, Copolymers of these resins and the like. The organic fillers may be used alone or in combination of two or more.

From the viewpoint of thermal decomposition property, the material of the organic filler is preferably at least one selected from the group consisting of an acrylic resin, a cellulose resin, and a polystyrene resin, and more preferably an acrylic resin.

Examples of the monomer constituting the acrylic resin include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl acrylate, and methyl group. Isopropyl acrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, second butyl acrylate, second butyl methacrylate, tert-butyl acrylate, A Tert-butyl acrylate, amyl acrylate, amyl methacrylate, hexyl acrylate, hexyl methacrylate, heptyl acrylate, heptyl methacrylate, 2-ethylhexyl acrylate, methacrylate 2- Ethylhexyl ester, octyl acrylate, octyl methacrylate, decyl acrylate, decyl methacrylate, decyl acrylate, decyl methacrylate, dodecyl acrylate, dodecyl methacrylate , tetradecyl acrylate, tetradecyl methacrylate, cetyl acrylate, cetyl methacrylate, octadecyl acrylate, octadecyl methacrylate, acrylic acid twenty Alkyl ester, eicosyl methacrylate, behenyl acrylate, behenyl methacrylate, cyclopentyl acrylate, cyclopentyl methacrylate, cyclohexyl acrylate, methyl Cyclohexyl acrylate, cycloheptyl acrylate, cycloheptyl methacrylate, benzyl acrylate, benzyl methacrylate, phenyl acrylate, phenyl methacrylate, methoxyethyl acrylate, methoxy methacrylate Ethyl ester, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylate Ester, methacrylic acid Dimethylaminopropyl acrylate, 2-chloroethyl acrylate, 2-chloroethyl methacrylate, 2-fluoroethyl acrylate, 2-fluoroethyl methacrylate, styrene, α-methyl styrene, Cyclohexylmaleimide, dicyclopentanyl acrylate, dicyclopentanyl methacrylate, vinyl toluene, vinyl chloride, vinyl acetate, N-vinylpyrrolidone, butadiene, isoprene, Chloroprene and the like. These monomers may be used alone or in combination of two or more.

The organic filler is a solid in a liquid medium. From the viewpoint of the passivation effect and the printability, an organic filler which is excellent in dispersibility in a liquid medium at normal temperature (25 ° C) is preferable, and an organic filler which is stable in a dispersion liquid is preferable. In the case of such an organic filler, the uniformity of the formed passivation layer is further improved, and the desired passivation effect can be stably obtained.

The organic filler is preferably decomposed at 30 ° C to 400 ° C, and the decomposition temperature is preferably from 40 ° C to 300 ° C, and more preferably from 50 ° C to 250 ° C. When the organic filler is decomposed at 400 ° C or lower, the step of forming a composition layer from the composition for forming a passivation layer and heat-treating (calcining) the composition layer to form a passivation layer, the residual of the organic filler is suppressed. Preferably.

The decomposition temperature can be measured by a thermogravimetric analyzer (Shimadzu Corporation, DTG-60H). In addition, the decomposition temperature herein means a temperature at which the weight of the substance starts to decrease due to the influence of heat.

When the organic filler is in the form of particles, the volume average particle diameter is preferably 10 μm or less, more preferably 1 μm or less, and still more preferably 0.1 μm or less. By having a volume average particle diameter of 10 μm or less, a large amount of thixotropy can be obtained with a small amount of addition. tendency. Moreover, when the screen printing method is used as a method of providing a composition for forming a passivation layer, generation of clogging of the mesh of the printing mask is suppressed.

Here, the volume average particle diameter of the organic filler can be measured by a laser diffraction scattering particle size distribution measuring apparatus (for example, Beckman Coulter LS13320), and the median diameter can be calculated from the obtained particle size distribution. The value is set to the average particle diameter. Further, the average particle diameter can also be determined by observation using a scanning electron microscope (SEM).

The content of the specific compound contained in the composition for forming a passivation layer can be appropriately selected as needed. For example, from the viewpoint of the printability and the passivation effect, the composition for forming a passivation layer can be set to 0.01% by mass to 70% by mass, preferably 0.01% by mass to 60% by mass, more preferably 0.01% by mass. 50% by mass.

(resin)

The composition for forming a passivation layer may further contain at least one resin. Further, the shape stability of the composition layer formed by imparting a composition for forming a passivation layer onto the semiconductor substrate by containing a resin is further improved, and passivation can be selectively formed in a desired shape in a region where the composition layer is formed. Floor.

The kind of the resin is not particularly limited. In particular, when the composition for forming a passivation layer is applied to a semiconductor substrate, the viscosity can be adjusted to a resin in a range in which good pattern formation can be performed. Specific examples of the resin include polyvinyl alcohol, polypropylene decylamine, polypropylene decylamine derivative, polyvinyl decylamine, polyvinyl decylamine derivative, polyvinylpyrrolidone, polyethylene oxide, and polycyclic ring. Oxyethane derivative, polysulfonic acid, acrylamide alkylsulfonic acid, cellulose, cellulose derivative (carboxymethyl cellulose, Hydroxyethyl cellulose, cellulose ether such as ethyl cellulose, etc.), gelatin, gelatin derivatives, starch, starch derivatives, sodium alginate, sodium alginate derivatives, xanthan, and triterpenoids , guar gum, guar gum derivatives, scleroglucan, scleroglucan derivatives, tragacanth gum, tragacanth derivatives, dextrin , dextrin derivative, (meth)acrylic resin, (meth) acrylate resin (alkyl (meth) acrylate resin, dimethylaminoethyl methacrylate resin, etc.), butadiene Resin, styrene resin, decane resin, copolymers of these, and the like. These resins may be used alone or in combination of two or more.

In the present specification, "(meth)acrylic acid" means at least one of "acrylic acid" and "methacrylic acid", and "(meth)acrylate" means "acrylic acid ester" and "methyl group". At least one of acrylates.

Among these resins, from the viewpoint of storage stability and pattern formation, it is preferred to use a neutral resin having no acidic or basic functional groups, and it is easy to adjust even when the content is small. From the viewpoint of viscosity and thixotropy, it is more preferred to use a cellulose derivative such as ethyl cellulose.

Further, the molecular weight of the resins is not particularly limited, and is preferably adjusted as appropriate in consideration of the desired viscosity as a composition for forming a passivation layer. The weight average molecular weight of the resin is preferably from 100 to 10,000,000, more preferably from 1,000 to 5,000,000, from the viewpoint of storage stability and pattern formability. Further, the weight average molecular weight of the resin was determined by conversion using a calibration curve of standard polystyrene by a molecular weight distribution measured by Gel Permeation Chromatography (GPC). The molecular weight of the resin is in the above formula (III) The compounds shown are measured under the same measurement conditions.

When the composition for forming a passivation layer contains a resin, the content of the resin in the composition for forming a passivation layer may be appropriately selected as needed. For example, when the composition for forming a passivation layer contains a resin, the content of the resin in the composition for forming a passivation layer is preferably from 0.1% by mass to 50% by mass. The content ratio is more preferably from 0.2% by mass to 25% by mass, even more preferably from 0.5% by mass to 20% by mass, even more preferably 0.5% by mass, from the viewpoint of exhibiting thixotropy such as pattern formation more easily. 15% by mass.

In the case where the composition for forming a passivation layer contains a resin, the compound of the formula (I) in the composition for forming a passivation layer (in the case of further containing a specific organoaluminum compound, means a compound of the formula (I) and a specific organoaluminum compound The content ratio (mass ratio) of the total amount) to the resin may be appropriately selected as needed. In the case of pattern formation property and storage stability, the content ratio of the resin to the compound of the formula (I) (resin / compound of the formula (I)) and the case of containing a specific organoaluminum compound means that the resin is relative to the resin. The content ratio of the total amount of the compound of the formula (I) and the specific organoaluminum compound [resin / (formula (I) compound + specific organoaluminum compound)] is preferably from 0.001 to 1,000, more preferably from 0.01 to 100, and still more preferably 0.1. ~1.

(liquid medium)

The composition for forming a passivation layer may further contain a liquid medium (solvent or dispersion medium). When the composition for forming a passivation layer contains a liquid medium, the viscosity is adjusted more easily, and the impartability is further improved, and a more uniform passivation layer tends to be formed. The liquid medium is not particularly limited and may be appropriately selected as needed. Among them, it is preferable to The liquid medium of the compound of the formula (I) and a specific organoaluminum compound or resin which are optionally used to dissolve to obtain a uniform solution or dispersion, more preferably contains at least one organic solvent.

Further, in the compound of the formula (I), the compound is easily cured by hydrolysis, polymerization or the like while remaining as it is. However, by dissolving or dispersing the compound of the formula (I) in a liquid medium, the reaction is suppressed. There is a tendency for storage stability to be easily improved.

Specific examples of the liquid medium include acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl isopropyl ketone, methyl n-butyl ketone, methyl isobutyl ketone, and methyl n-amyl ketone. Methyl n-hexyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, trimethyl fluorenone, cyclohexanone, cyclopentanone, methylcyclohexanone, 2,4-pentanedione, Ketone solvent such as acetone-acetone; diethyl ether, methyl ethyl ether, methyl n-propyl ether, diisopropyl ether, tetrahydrofuran, methyl tetrahydrofuran, dioxane, dimethyl dioxane, ethylene glycol Ether, ethylene glycol diethyl ether, ethylene glycol di-n-propyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, two Glycol methyl n-propyl ether, diethylene glycol methyl n-butyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n-butyl ether, diethylene glycol methyl n-hexyl ether, triethyl Diol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol methyl ethyl ether, triethylene glycol methyl n-butyl ether, triethylene glycol di-n-butyl ether, triethylene glycol methyl Ether, tetraethylene glycol dimethyl ether, tetraethylene glycol Ether, tetraethylene glycol methyl ethyl ether, tetraethylene glycol methyl n-butyl ether, tetraethylene glycol di-n-butyl ether, tetraethylene glycol methyl n-hexyl ether, tetraethylene glycol di-n-butyl ether , propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol di-n-propyl ether, propylene glycol dibutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol methyl ethyl ether, dipropylene Alcohol methyl n-butyl ether, dipropylene glycol di-n-propyl ether, dipropylene glycol di-n-butyl ether, dipropylene glycol methyl n-hexyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, tripropylene glycol methyl ethyl ether, three Propylene glycol methyl n-butyl ether, tripropylene glycol di-n-butyl ether, tripropylene glycol methyl n-hexyl ether, tetrapropylene glycol dimethyl ether, tetrapropylene glycol diethyl ether, tetrapropylene glycol methyl ethyl ether, tetrapropylene glycol methyl n-butyl ether , an ether solvent such as tetrapropylene glycol di-n-butyl ether, tetrapropylene glycol methyl n-hexyl ether or tetrapropylene glycol di-n-butyl ether; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, acetic acid Isobutyl ester, second butyl acetate, n-amyl acetate, second amyl acetate, 3-methoxybutyl acetate, methyl amyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate Ester, 2-(2-butoxyethoxy)ethyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, decyl acetate, methyl acetate, ethyl acetate, Diethylene glycol methyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, dipropylene glycol acetate Ethyl ether, glycol diacetate, methoxytriethylene glycol acetate, isoamyl acetate, ethyl propionate, n-butyl propionate, isoamyl propionate, diethyl oxalate, di-n-butyl oxalate , methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, ethylene glycol methyl ether propionate, ethylene glycol ether propionate, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether Ester, propylene glycol methyl ether acetate, propylene glycol diethyl ether acetate, propylene glycol propyl ether acetate, γ-butyrolactone, γ-valerolactone and other ester solvents; acetonitrile, N-methylpyrrolidone, N-ethyl Pyrrolidone, N-propylpyrrolidone, N-butylpyrrolidone, N-hexylpyrrolidone, N-cyclohexylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl Aprotic polar solvents such as Aachen; dichloromethane, chloroform, dichloroethane, benzene, toluene, xylene, hexane, octane, ethylbenzene, 2-ethylhexanoic acid, methyl isobutyl ketone, Hydrophobic organic solvent such as methyl ethyl ketone; methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, second butanol, third butanol, n-pentanol, isoamyl alcohol, 2 -methylbutanol, second pentanol, third pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, second hexanol, 2-ethylbutanol, second heptanol , n-octanol, 2-ethylhexanol, second octanol, n-nonanol, n-nonanol, second-undecyl alcohol, trimethyldecyl alcohol, second-tetradecanol, second - heptadecyl alcohol, cyclohexanol, methylcyclohexanol, benzyl alcohol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, Alcohol solvent such as tripropylene glycol or isobornylcyclohexanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethyl Glycol mono-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxy triethylene glycol, tetraethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol single a glycol monoether solvent such as methyl ether; terpinene, terpineol, and myrcene Myrcene), allophymene, limonene, dipentene, decene, carbon, ocimene, phellandrene, etc.; terpene solvent; water, etc. These liquid mediums may be used alone or in combination of two or more.

In view of the impartability and pattern formation property of the semiconductor substrate, the liquid medium preferably contains at least one selected from the group consisting of a terpene solvent, an ester solvent, and an alcohol solvent, and more preferably contains At least one selected from the group consisting of terpene solvents is selected.

In addition, a high viscosity and low boiling point (high viscosity low boiling point solvent) can also be used as the liquid medium. The composition for forming a passivation layer containing a high-viscosity and low-boiling point solvent has the advantage that the composition layer formed to be sufficiently applied to the semiconductor substrate can be sufficiently maintained. The viscosity of the shape is volatilized in the middle of the subsequent heat treatment (calcination) step, so that the influence of the residual solvent is suppressed. Specific examples of the high viscosity low boiling point solvent include isobornylcyclohexanol and the like.

Isobornylcyclohexanol is commercially available as "Terusolve MTPH" (Japanese Terpene Chemical Co., Ltd., trade name). The isobornyl cyclohexanol has a boiling point as high as 308 ° C to 318 ° C. When it is removed from the composition layer, it is not required to be degreased by heat treatment (calcination) as a resin, but can be vaporized by heating. This makes it disappear. Therefore, most of the solvent and the isobornylcyclohexanol contained in the composition for forming a passivation layer can be removed in the drying step after the application to the semiconductor substrate.

When the composition for forming a passivation layer contains a material having a high viscosity and a low boiling point, the content of the high-viscosity low-boiling material is preferably from 3% by mass to 95% by mass based on the total mass of the composition for forming a passivation layer, more preferably 5% by mass to 90% by mass, particularly preferably 7% by mass to 80% by mass.

When the composition for forming a passivation layer contains a liquid medium, the content of the liquid medium is determined in consideration of impartability, pattern formation property, and storage stability. For example, the content of the liquid medium is preferably from 5% by mass to 98% by mass, and more preferably 10% by mass based on the total mass of the composition for forming a passivation layer, from the viewpoint of the impartability of the composition and the pattern formation property. %~95% by mass.

(other additives)

The composition for forming a passivation layer may also contain an acidic compound or a basic compound. When the composition for forming a passivation layer contains an acidic compound or a basic compound, In view of the storage stability, the content of the acidic compound or the basic compound is preferably 1% by mass or less, and more preferably 0.1% by mass or less, based on the composition for forming a passivation layer.

The acidic compound may be listed as a Brilliant acid and a Lewis acid. Specific examples thereof include inorganic acids such as hydrochloric acid and nitric acid; and organic acids such as acetic acid. In addition, examples of the basic compound include a Bronsted base and a Lewis base. Specific examples of the basic compound include inorganic bases such as alkali metal hydroxides and alkaline earth metal hydroxides, and organic bases such as trialkylamine and pyridine. .

The composition for forming a passivation layer may further contain at least one oxide selected from the group consisting of Nb, Ta, V, Y, and Hf (hereinafter also referred to as "specific oxide"). Since the specific oxide is an oxide formed by heat-treating (calcining) the compound of the formula (I), it is expected that the passivation layer formed of the composition for forming a passivation layer containing a specific oxide exhibits an excellent passivation effect.

Further, the composition for forming a passivation layer may further contain aluminum oxide (Al ₂ O ₃ ). Alumina is an oxide formed by subjecting a compound represented by the formula (II) to heat treatment (calcination). Therefore, it is expected that the passivation layer-forming composition containing the compound of the formula (I) and aluminum oxide exhibits an excellent passivation effect.

(physical value)

The viscosity of the composition for forming a passivation layer is not particularly limited, and can be appropriately selected depending on the method of applying the semiconductor substrate or the like. For example, the viscosity of the composition for forming a passivation layer can be set to 0.01 Pa. s~10000Pa. s. Among them, the viscosity of the composition for forming a passivation layer is preferably 0.1 Pa from the viewpoint of pattern formation. s~1000Pa. s. Further, the viscosity was measured at a shear rate of 1.0 s ^-1 at 25 ° C using a rotary shear viscometer.

Further, the shear viscosity of the composition for forming a passivation layer is not particularly limited, and it is preferred that the composition for forming a passivation layer has thixotropic properties. Among them, from the viewpoint of pattern formation, the shear viscosity η ₁ at a shear rate of 1.0 s ^-1 is divided by the shear viscosity η ₂ at a shear rate of 10 s ^-1 (η _{1 )} /η ₂ ) is preferably from 1.05 to 100, more preferably from 1.1 to 50. Further, the shear viscosity was measured at a temperature of 25 ° C using a rotary shear viscometer equipped with a cone plate (having a diameter of 50 mm and a taper angle of 1 °).

Further, the content of each component and the content of each component contained in the composition for forming a passivation layer can be determined by thermal analysis such as thermogravimetric-differential thermal analysis (TG/DTA) or nuclear magnetic resonance (Nuclear Magnetic Resonance, It is confirmed by spectral analysis such as NMR), infrared spectroscopy (IR), high performance liquid chromatography (HPLC), or gel permeation chromatography (GPC).

(Method for Producing Composition for Passivation Layer Formation)

The method for producing the composition for forming a passivation layer is not particularly limited. For example, a composition for forming a passivation layer can be produced by using at least a compound represented by the formula (I) selected from a fatty acid decylamine, a polyolefin diol compound, and an organic filler by a usual mixing method. A liquid medium or the like contained as needed is mixed. Further, a composition for forming a passivation layer can be produced by dissolving at least one selected from the group consisting of fatty acid decylamine, polyolefin diol compound, and organic filler. After dissolving in a liquid medium, it is mixed with the compound represented by the formula (I).

Further, the compound represented by the formula (I) can also be produced by mixing an alkoxide of a metal contained in the compound of the formula (I) with a compound which can form a chelate with the above metal. At this time, a liquid medium may be used as needed, and heat treatment may be performed. The compound of the formula (I) thus prepared may be mixed with a solution or dispersion containing at least one selected from the group consisting of fatty acid decylamine, polyolefin diol compound and organic filler to prepare a composition for forming a passivation layer.

<Semiconductor Substrate with Passivation Layer>

The semiconductor substrate with a passivation layer of the present invention has a semiconductor substrate and a passivation layer which is a heat-treated product (calcined material) which is provided on the entire surface or a part of the semiconductor substrate and which is a composition for forming the passivation layer. . The semiconductor substrate with the passivation layer has a passivation layer as a heat treatment layer (calcined layer) of a composition for forming a passivation layer, thereby exhibiting an excellent passivation effect.

The semiconductor substrate is not particularly limited, and may be appropriately selected from those generally used depending on the purpose. Examples of the semiconductor substrate include those in which p-type impurities or n-type impurities are doped (diffused) in ruthenium, osmium or the like. Among them, a tantalum substrate is preferred. Further, the semiconductor substrate may be a p-type semiconductor substrate or an n-type semiconductor substrate. Among them, from the viewpoint of the passivation effect, a semiconductor substrate in which the surface on which the passivation layer is formed is a p-type layer is preferable. The p-type layer on the semiconductor substrate may be a p-type layer derived from a p-type semiconductor substrate, or may be formed on an n-type semiconductor substrate or a p-type semiconductor substrate as a p-type diffusion layer or a p ⁺ -type diffusion layer.

The thickness of the semiconductor substrate is not particularly limited and may be appropriately selected depending on the purpose. Choose. For example, the thickness of the semiconductor substrate can be set to 50 μm to 1000 μm, preferably 75 μm to 750 μm.

The thickness of the passivation layer formed on the semiconductor substrate is not particularly limited and may be appropriately selected depending on the purpose. For example, the thickness of the passivation layer is preferably 5 nm to 50 μm, more preferably 10 nm to 30 μm, and still more preferably 15 nm to 20 μm.

The semiconductor substrate with the passivation layer can be applied to a solar cell element, a light emitting diode element, or the like. For example, a solar cell element excellent in conversion efficiency can be obtained by being applied to a solar cell element.

<Method of Manufacturing Semiconductor Substrate with Passivation Layer>

A method for producing a semiconductor substrate with a passivation layer according to the present invention includes the steps of: providing a composition for forming a passivation layer on an entire surface or a portion of a semiconductor substrate to form a composition layer; and performing the composition layer A step of forming a passivation layer by heat treatment (calcination). The above manufacturing method may further include other steps as needed.

By using the composition for forming a passivation layer of the present invention, a passivation layer having an excellent passivation effect can be formed into a desired shape by a simple method.

The method of fabricating the semiconductor substrate with the passivation layer is preferably a step of providing an alkaline aqueous solution on the semiconductor substrate before the step of forming the composition layer. In other words, it is preferable to clean the surface of the semiconductor substrate with an alkaline aqueous solution before applying the composition for forming a passivation layer on the semiconductor substrate. By washing with an alkaline aqueous solution, organic substances, particles, and the like existing on the surface of the semiconductor substrate can be removed, and the passivation effect can be further improved. A cleaning method using an alkaline aqueous solution can be exemplified as usual Known RCA (Radio Corporation of America) cleaning, etc. For example, by immersing the semiconductor substrate in a mixed solution of aqueous ammonia-hydrogen peroxide water and treating it at 60 to 80 ° C, the organic material and the particles can be removed to clean the semiconductor substrate. The cleaning time is preferably from 10 seconds to 10 minutes, and preferably from 30 seconds to 5 minutes.

The method of forming a composition layer by providing a composition for forming a passivation layer on a semiconductor substrate is not particularly limited. For example, a method of providing a composition for forming a passivation layer on a semiconductor substrate by using a known method or the like can be mentioned. Specific examples thereof include a dipping method, a printing method, a dispenser method, a spin coating method, a brush coating method, a spray method, a doctor blade method, a roll coating method, and an inkjet method. Among these methods, from the viewpoint of pattern formability, various printing methods (for example, screen printing), an inkjet method, and the like are preferable. The composition for forming a passivation layer of the present invention is excellent in printability and coating film uniformity even when applied to a printing method.

The amount of the composition for forming a passivation layer can be appropriately selected depending on the purpose. For example, the thickness of the passivation layer to be formed can be appropriately adjusted so as to become a desired thickness to be described later.

The composition layer formed by the composition for forming a passivation layer is subjected to heat treatment (calcination) to form a heat-treated material layer (calcined material layer) derived from the composition layer, whereby a passivation layer can be formed on the semiconductor substrate.

The heat treatment (calcination) condition of the composition layer is such that the compound represented by the formula (I) contained in the composition layer and the compound represented by the formula (II) contained as necessary can be converted into a metal as a heat-treated product (calcined product). Oxide or composite oxide, there is no Special restrictions. Among them, a heat treatment (calcination) condition in which an amorphous metal oxide layer can be formed is preferable. By including the amorphous metal oxide layer in the passivation layer, the passivation layer can be more effectively negatively charged, and a more excellent passivation effect can be obtained. Specifically, the heat treatment (calcination) temperature is preferably from 400 ° C to 900 ° C, more preferably from 450 ° C to 800 ° C. The heat treatment (calcination) temperature herein means the highest temperature in the furnace used in the heat treatment (calcination). Further, the heat treatment (calcination) time can be appropriately selected depending on the heat treatment (calcination) temperature and the like. For example, it can be set to be within 10 hours, preferably within 5 hours. The term "heat treatment (calcination)" as used herein refers to the retention time at the highest temperature.

Furthermore, heat treatment (calcination) can be carried out using a diffusion furnace (for example, ACCURON CQ-1200, ACCURON DD-200P, both Hitachi International Electric Co., Ltd.; 206A-M100, Optical Ocean Thermal System ( Koyo-Thermo System), etc.). The environment in which the heat treatment (calcination) is carried out is not particularly limited and can be carried out in the atmosphere.

The thickness of the passivation layer produced by the method for producing a semiconductor substrate with a passivation layer is not particularly limited and may be appropriately selected depending on the purpose. For example, the average thickness of the passivation layer is preferably from 5 nm to 50 μm, more preferably from 10 nm to 30 μm, and even more preferably from 15 nm to 20 μm.

Further, the average thickness of the formed passivation layer was calculated by using a stylus type step/surface shape measuring device (for example, Ambios) by measuring the thickness of three points by a usual method and calculating the arithmetic mean value.

The method of manufacturing a semiconductor substrate having a passivation layer may be performed by heat treatment (calcination) after imparting a composition for forming a passivation layer onto a semiconductor substrate. Before the step of forming the passivation layer, the step of drying the composition layer containing the composition for forming a passivation layer is further included. By having a step of drying the composition layer, a passivation layer having a more uniform passivation effect can be formed.

The step of drying the composition layer is not particularly limited as long as at least a part of the liquid medium which may be contained in the composition for forming a passivation layer can be removed. The drying treatment can be set, for example, at 30 ° C to 250 ° C for 1 minute to 60 minutes, preferably at 40 ° C to 220 ° C for 3 minutes to 40 minutes. Further, the drying treatment can be carried out under normal pressure or under reduced pressure.

When the composition for forming a passivation layer contains a resin, the method for producing a semiconductor substrate with a passivation layer may be performed after the step of forming a passivation layer by heat treatment (calcination) after the composition for forming a passivation layer is formed. A step of degreasing the composition layer containing the composition for forming a passivation layer is included. By having a step of degreasing the composition layer, a passivation layer having a more uniform passivation effect can be formed.

The step of degreasing the composition layer is not particularly limited as long as at least a part of the resin sometimes contained in the composition for forming a passivation layer can be removed. The degreasing treatment can be performed, for example, at a temperature of from 250 ° C to 450 ° C for 10 minutes to 120 minutes, preferably from 300 ° C to 400 ° C for 3 minutes to 60 minutes. The degreasing treatment is preferably carried out in the presence of oxygen, more preferably in the atmosphere.

<Solar battery component>

The solar cell element of the present invention comprises: a semiconductor substrate obtained by pn-bonding a p-type layer and an n-type layer; and a passivation layer provided on the entire surface of the semiconductor substrate Or a part of the heat-treated product (calcined product) of the composition for forming a passivation layer; and an electrode disposed on one or more layers selected from the group consisting of the p-type layer and the n-type layer. The above solar cell element may have other components as needed.

The solar cell element is excellent in conversion efficiency by having a passivation layer formed of the composition for forming a passivation layer of the present invention.

The semiconductor substrate to which the composition for forming a passivation layer is applied is not particularly limited, and may be appropriately selected from those generally used depending on the purpose. The semiconductor substrate can be described in a semiconductor substrate with a passivation layer, and the user can preferably be the same. The surface of the semiconductor substrate provided with the passivation layer is preferably a p-type layer.

The thickness of the passivation layer formed on the semiconductor substrate is not particularly limited and may be appropriately selected depending on the purpose. For example, the average thickness of the passivation layer is preferably from 5 nm to 50 μm, more preferably from 10 nm to 30 μm, and even more preferably from 15 nm to 20 μm.

The shape and size of the solar cell elements are not limited. For example, it is preferably a substantially square having a side of 125 mm to 156 mm.

<Method of Manufacturing Solar Cell Element>

The method for producing a solar cell element of the present invention comprises the steps of: forming a pn junction in which a p-type layer and an n-type layer are joined, and in a group selected from the group consisting of the p-type layer and the n-type layer; a step of forming a composition for forming a passivation layer to form a composition layer on one or both surfaces of a surface of the semiconductor substrate having an electrode having one or more electrodes on one or more layers; and heat-treating the composition layer Calcination), the step of forming a passivation layer. Method for manufacturing solar cell components as needed You can also include other steps.

By using a composition for forming a passivation layer, a solar cell element having a passivation layer having an excellent passivation effect and having excellent conversion efficiency can be produced by a simple method. Further, the passivation layer can be formed on the semiconductor substrate on which the electrode is formed so as to have a desired shape, and the solar cell element is excellent in productivity.

A semiconductor substrate having a pn junction in which electrodes are disposed on at least one of a p-type layer and an n-type layer can be manufactured by a commonly used method. For example, it can be manufactured by applying a paste for forming an electrode such as a silver paste or an aluminum paste to a desired region of a semiconductor substrate, and performing heat treatment (calcination) as necessary.

The surface of the semiconductor substrate provided with the passivation layer may be a p-type layer or an n-type layer. Among them, from the viewpoint of conversion efficiency, a p-type layer is preferred.

The details of the method of forming the passivation layer using the composition for forming a passivation layer are the same as those of the semiconductor substrate with the passivation layer described above, and the preferred embodiment is also the same.

The thickness of the passivation layer formed on the semiconductor substrate is not particularly limited and may be appropriately selected depending on the purpose. For example, the average thickness of the passivation layer is preferably from 5 nm to 50 μm, more preferably from 10 nm to 30 μm, and even more preferably from 15 nm to 20 μm.

Next, an embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is a cross-sectional view showing a step diagram schematically showing an example of a method of manufacturing a solar cell element having a passivation layer according to the present embodiment. However, this step chart does not limit the invention in any way.

As shown in FIG. 1(a), on the p-type semiconductor substrate 1, an n ⁺ -type diffusion layer 2 is formed in the vicinity of the surface, and an anti-reflection film 3 is formed on the outermost surface. Examples of the antireflection film 3 include a tantalum nitride film, a titanium oxide film, and the like. Further, a surface protective film (not shown) such as ruthenium oxide may be further present between the anti-reflection film 3 and the p-type semiconductor substrate 1. Further, the passivation layer of the present invention can also be used as a surface protective film.

Then, as shown in FIG. 1(b), a material for forming the back surface electrode 5 such as an aluminum electrode paste is applied to a part of the back surface surface, and then heat treatment (calcination) is performed to form the back surface electrode 5, and aluminum atoms are diffused to the p-type. The p ⁺ -type diffusion layer 4 is formed in the semiconductor substrate 1.

Then, as shown in FIG. 1(c), the electrode forming paste is applied to the light-receiving surface side, and then heat-treated (calcined) to form the light-receiving surface electrode 7. By using a glass powder containing a burnt-through glass powder as an electrode forming paste, the light-receiving surface electrode 7 can be formed on the n ⁺ -type diffusion layer 2 through the anti-reflection film 3 as shown in FIG. 1( c ). Ohmic contact.

Then, as shown in FIG. 1(d), a composition for forming a passivation layer is provided on the p-type layer on the back surface other than the region in which the back surface electrode 5 is formed, and a composition layer is formed by screen printing or the like. The composition layer formed on the p-type layer is subjected to heat treatment (calcination) to form a passivation layer 6. The passivation layer 6 formed of the composition for forming a passivation layer of the present invention is formed on the p-type layer on the back surface, whereby a solar cell element excellent in power generation efficiency can be manufactured.

Manufactured using a manufacturing method including the manufacturing steps shown in FIG. In the anode battery element, the back surface electrode formed of aluminum or the like can be set to a point contact structure, and warpage of the substrate or the like can be reduced. Further, by using the composition for forming a passivation layer, the passivation layer can be formed with excellent productivity at a specific position (specifically, on a p-type layer other than the region where the electrode is formed).

Further, although (d) of FIG. 1 shows a method of forming a passivation layer only on the back surface portion, a composition for forming a passivation layer may be provided on the side surface in addition to the back surface side of the p-type semiconductor substrate 1, Further, heat treatment (calcination) is performed, and a passivation layer 6 (not shown) is further formed on the side surface (edge) of the semiconductor substrate 1. Thereby, a solar cell element having more excellent power generation efficiency can be manufactured.

Further, the passivation layer may be formed on the side surface only by forming a passivation layer on the side surface, and heat-treating (calcining) the composition for forming a passivation layer of the present invention. When the composition for forming a passivation layer of the present invention is used for a portion having a large number of crystal defects such as a side surface, the effect is particularly large.

Although an embodiment in which a passivation layer is formed after forming an electrode has been described in FIG. 1, an electrode such as aluminum may be formed in a desired region by vapor deposition or the like after forming a passivation layer.

Fig. 2 is a cross-sectional view showing a step diagram schematically showing another example of a method of manufacturing a solar cell element having a passivation layer according to the present embodiment. Specifically, FIG. 2 illustrates a step diagram including a step of forming a p-type diffusion layer forming composition using an aluminum electrode paste or a p ⁺ -type diffusion layer by thermal diffusion treatment in the form of a cross-sectional view. ^{After the +} type diffusion layer, the heat-treated product of the aluminum electrode paste or the heat-treated product of the p ⁺ -type diffusion layer forming composition is removed. Here, examples of the composition for forming a p-type diffusion layer include a composition containing a substance containing an acceptor element and a glass component.

As shown in FIG. 2(a), on the p-type semiconductor substrate 1, an n ⁺ -type diffusion layer 2 is formed in the vicinity of the surface, and an anti-reflection film 3 is formed on the surface. Examples of the antireflection film 3 include a tantalum nitride film, a titanium oxide film, and the like.

Then, as shown in FIG. 2(b), the p-type diffusion layer forming composition is applied to a part of the back surface region, and then heat-treated to form the p ⁺ -type diffusion layer 4. A heat-treated product 8 of a p-type diffusion layer-forming composition is formed on the p ⁺ -type diffusion layer 4 .

Here, an aluminum electrode paste may be used instead of the p-type diffusion layer forming composition. In the case of using an aluminum electrode paste, an aluminum electrode 8 is formed on the p ⁺ -type diffusion layer 4.

Then, as shown in FIG. 2(c), the heat-treated product 8 or the aluminum electrode 8 of the p-type diffusion layer-forming composition formed on the p ⁺ -type diffusion layer 4 is removed by etching or the like.

Then, as shown in FIG. 2(d), the electrode forming paste is selectively applied to a part of the light-receiving surface (surface) and the back surface, and heat treatment is performed to form the light-receiving surface electrode 7 on the light-receiving surface (surface). The back electrode 5 is formed on the back surface. By using the glass powder having the burnthrough property as the paste for electrode formation provided on the light-receiving surface side, the anti-reflection film 3 can be formed through the anti-reflection film 3 to form the n ⁺ -type diffusion layer 2 as shown in FIG. 2(c). The light receiving surface electrode 7 obtains an ohmic contact.

Further, since the p ⁺ -type diffusion layer 4 is formed in the region where the back surface electrode is formed, the electrode forming paste for forming the back surface electrode 5 is not limited to the aluminum electrode paste, and a silver electrode paste or the like can be used to form a lower electric resistance. A paste for the electrode of the electrode. Thereby, power generation efficiency can be further improved.

Then, as shown in FIG. 2(e), a composition for forming a passivation layer is provided on the p-type layer on the back surface other than the region in which the back surface electrode 5 is formed, and a composition layer is formed. The application can be carried out by a method such as screen printing. The composition layer formed on the p ⁺ -type diffusion layer 4 is subjected to heat treatment (calcination) to form a passivation layer 6. By forming the passivation layer 6 formed of the composition for forming a passivation layer of the present invention on the p-type layer on the back surface, a solar cell element excellent in power generation efficiency can be produced.

Further, although (e) of FIG. 2 shows a method of forming a passivation layer only on the back surface portion, a material for a passivation layer may be provided on the side surface in addition to the back surface side of the p-type semiconductor substrate 1, and heat treatment (calcination) may be performed. Thereby, a passivation layer (not shown) is further formed on the side surface (edge) of the p-type semiconductor substrate 1. Thereby, a solar cell element having more excellent power generation efficiency can be manufactured.

Further, a passivation layer may be formed on the side surface, and the passivation layer-forming composition of the present invention may be applied only to the side surface, and heat-treated (calcined) to form a passivation layer. When the composition for forming a passivation layer of the present invention is used for a portion having a large number of crystal defects such as a side surface, the effect is particularly large.

Although an embodiment in which a passivation layer is formed after forming an electrode has been described in FIG. 2, an electrode such as aluminum may be further formed in a desired region by vapor deposition or the like after forming a passivation layer.

In the above embodiment, a case where a p-type semiconductor substrate having an n ⁺ -type diffusion layer formed on a light-receiving surface is used, and when an n-type semiconductor substrate having a p ⁺ -type diffusion layer formed on a light-receiving surface is used, Solar cell components can also be manufactured in the same manner. Further, in this case, an n ⁺ -type diffusion layer is formed on the back side.

Further, the passivation layer forming composition can also be used to form the passivation layer 6 on the light-receiving surface side or the back surface side of the back electrode type solar cell element in which the electrode is disposed only on the back surface side as shown in FIG. 3 .

As shown in the schematic cross-sectional view of FIG. 3, an n ⁺ -type diffusion layer 2 is formed on the light-receiving surface side of the p-type semiconductor substrate 1 in the vicinity of the surface, and a passivation layer 6 and an anti-reflection film 3 are formed on the surface. As the antireflection film 3, a tantalum nitride film, a titanium oxide film, or the like is known. Further, the passivation layer 6 is formed by imparting heat treatment (calcination) to the composition for forming a passivation layer of the present invention.

On the back surface side of the p-type semiconductor substrate 1, the back surface electrode 5 is provided on each of the p ⁺ -type diffusion layer 4 and the n ⁺ -type diffusion layer 2, and further, a passivation layer 6 is provided in a region where the electrode is not formed on the back surface.

The p ⁺ -type diffusion layer 4 can be formed by applying a composition for forming a p-type diffusion layer or an aluminum electrode paste to a desired region as described above, and then performing heat treatment. Further, the n ⁺ -type diffusion layer 2 can be formed, for example, by applying a composition for forming an n-type diffusion layer which can form an n ⁺ -type diffusion layer by thermal diffusion treatment to a desired region, and then performing heat treatment. .

Here, examples of the composition for forming an n-type diffusion layer include a composition containing a donor element and a glass component.

The back surface electrode 5 provided on each of the p ⁺ -type diffusion layer 4 and the n ⁺ -type diffusion layer 2 can be formed using a paste for electrode formation which is generally used, such as a silver electrode paste.

Further, the back surface electrode 5 provided on the p ⁺ -type diffusion layer 4 may be an aluminum electrode formed by using an aluminum electrode paste together with the p ⁺ -type diffusion layer 4.

The passivation layer 6 provided on the back surface can be formed by imparting a composition for forming a passivation layer to a region where the back surface electrode 5 is not provided, and subjecting it to heat treatment (calcination).

Further, the passivation layer 6 may be formed not only on the back surface of the p-type semiconductor substrate 1 but also on the side surface (not shown).

Since the back electrode type solar cell element shown in FIG. 3 does not have an electrode on the light receiving surface side, it is excellent in power generation efficiency. Further, since the passivation layer is formed in the region where the electrode is not formed on the back surface, the conversion efficiency is further improved.

In the above, an example in which a p-type semiconductor substrate is used as a semiconductor substrate is shown. When an n-type semiconductor substrate is used, a solar cell element having excellent conversion efficiency can be manufactured in accordance with the above operation.

<solar battery>

The solar cell includes the solar cell element described above and a wiring material provided on an electrode of the solar cell element. Further, the solar battery may be connected to a plurality of solar cell elements via a wiring material such as a Tape Automated Bonding (TAB) wire, and may be sealed by a sealing material. The wiring material and the sealing material are not particularly limited and may be appropriately selected from those generally used in the art. There is no limit to the size of the solar cell. It is preferably 0.5 m ² to 3 m ² .

[Examples]

Hereinafter, the invention will be specifically described by way of examples, but the invention is not limited to the examples.

<Example 1>

(Preparation of Composition 1 for Passivation Layer Formation)

5.0 g of decylamine stearate and 45.0 g of terpineol were mixed, and stirred at 130 ° C for 1 hour to prepare a decylamine stearate solution. 10.01 g of ethyl cellulose and 90.02 g of terpineol were mixed, and the mixture was stirred at 150 ° C for 1 hour to prepare an ethyl cellulose solution. The composition of the passivation layer was prepared by mixing 2.22 g of ethanol oxime, 2.23 g of (ethyl ethyl acetonitrile) aluminum isopropoxide, 1.88 g of terpineol, 1.58 g of decylamine stearate solution and 7.92 g of ethyl cellulose solution. Matter 1. The content of the decylamine stearate in the composition 1 for passivation layer formation was 1.0%, and the content rate of the compound of the formula (I) was 14.0%.

(Evaluation of storage stability)

The shear viscosity of the composition 1 for passivation layer formation prepared above was measured after the preparation (within 12 hours) and after storage at 25 ° C for 30 days. For the measurement of the shear viscosity, a cone plate (having a diameter of 50 nm and a taper angle of 1°) was attached to an MCR301 of Anton Paar Co., Ltd., and measured at a shear rate of 1.0 s ^-1 at a temperature of 25 °C. The shear viscosity at 25 ° C was 28.2 Pa after preparation. s, stored at 25 ° C for 30 days after 29.8Pa. s.

(formation of passivation layer)

A single crystal type p-type ruthenium substrate (Mitsubishi Sumitomo (SUMCO) Co., Ltd., 50 mm square, thickness: 770 μm) having a mirror-shaped surface was used as the semiconductor substrate. The passivation layer-forming composition 1 obtained above was applied onto a ruthenium substrate by a screen printing method. The composition for forming a passivation layer 1 was applied in an amount such that the average thickness of the passivation layer obtained by heat treatment (calcination) was 300 μm.

The above printing was carried out 10 times in succession, and it was visually confirmed that the 10 sheets had no printing unevenness. The above-mentioned "printing unevenness" refers to a portion in which the above-described portion which is thinner than the surrounding portion which is partially peeled off when the screen is peeled off from the substrate.

In addition, it was confirmed by visual observation that the coating film after printing was uniform in 9 sheets out of 10 sheets. The state in which the coating film is uniform means that the composition for forming a passivation layer exists on the entire printing portion on the ruthenium substrate. Thereafter, the tantalum substrate to which the composition 1 for passivation layer formation was applied was dried at 150 ° C for 5 minutes. Then, heat treatment (calcination) was performed at 700 ° C for 10 minutes, and then left to cool at room temperature to prepare a substrate for evaluation. The heat treatment (calcination) is carried out in a diffusion furnace (Horizontal Diffusion Furnace DD-200P, Hitachi International Electric Co., Ltd.) under atmospheric conditions (flow rate: 5 L/min) at a maximum temperature of 700 ° C and a holding time of 10 minutes. get on.

The average thickness of the obtained passivation layer was measured by a conventional method using a stylus type step/surface shape measuring device (Ambios) to determine the thickness of three points, and was calculated as an arithmetic mean value.

(Measurement of effective life)

Lifetime measuring device (Sinton Instruments, WCT-120), the region in which the passivation layer of the substrate for evaluation obtained above was formed by the simulated constant state photoconductivity method at room temperature (25 ° C) The effective life (μs) was measured. The effective life is 880μs.

<Example 2>

Polyethylene glycol (number average molecular weight: 4000) 5.0 g and terpineol 45.0 g were mixed, and stirred at 100 ° C for 1 hour to prepare a polyethylene glycol solution. Ethanol 铌2.11 g, (ethyl ethyl acetonitrile acetic acid) 2.17 g of aluminum isopropoxide, 1.75 g of terpineol, 1.51 g of a polyethylene glycol solution, and 7.55 g of an ethyl cellulose solution were mixed to prepare a composition 2 for forming a passivation layer. The content of the polyethylene glycol in the composition for forming the passivation layer 2 was 1.0%, and the content of the compound of the formula (I) was 14.0%. In addition, the viscosity of the composition 2 for passivation layer formation was 35.5 Pa after preparation. s, after 3 days storage at 25 ° C, it is 37.8Pa. s.

A passivation layer was formed on the tantalum substrate in the same manner as in Example 1 except that the above-described composition for forming the passivation layer 2 was used, and the evaluation was performed in the same manner. Of the 10 screen printings, 9 were not printed unevenly. In addition, among the 10 sheets, the coating film was uniform for 7 pieces. The effective life is 801 μs.

<Example 3>

2.2 g of ethanol, 2.18 g of (ethyl acetoacetate) aluminum isopropoxide, 1.80 g of terpineol, MR-2G (organic filler, Polymethylmethacrylate, PMMA) A resin filler, a volume average particle diameter of 1.0 μm, and 1.51 g of an ethyl cellulose solution were mixed, and a composition for forming a passivation layer 3 was prepared. The content of MR-2G (referred to as MR in the table) in the composition 3 for forming a passivation layer of MR was 9.9%, and the content of the compound of the formula (I) was 13.9%. Further, the viscosity of the composition for forming the passivation layer 3 was 28.2 Pa after the preparation. s, after 3 days storage at 25 ° C, it is 32.3Pa. s.

A passivation layer was formed on the tantalum substrate in the same manner as in Example 1 except that the composition for forming passivation layer 3 prepared above was used, and the evaluation was performed in the same manner. Of the 10 screen printings, 10 were not printed unevenly. In addition, in 10 sheets, the coating film was uniform for 10 pieces. The effective life is 627 μs.

<Comparative Example 1>

In the same manner as in Example 1, except that the addition of the composition 1 for the formation of the passivation layer was not carried out, the evaluation substrate was prepared, and the effective life was measured and evaluated. The effective life is 20μs.

<Comparative Example 2>

The composition C1 was prepared by mixing 2.10 g of ethanol oxime, 2.17 g of (ethyl acetoacetic acid) aluminum isopropoxide, 3.31 g of terpineol, and 7.63 g of an ethyl cellulose solution. The viscosity of the composition C1 was 23.5 Pa immediately after preparation. s, stored at 25 ° C for 30 days after 24.8Pa. s.

A passivation layer was formed on the tantalum substrate in the same manner as in Example 1 except that the composition C1 prepared above was used, and the evaluation was performed in the same manner. Of the 10 screen printing, there were 4 prints without uneven printing. In addition, in 10 sheets, the coating film was uniform to 0 pieces. The effective life is 1077 μs.

<Comparative Example 3>

The composition C2 was prepared by mixing 0.80 g of a decylamine stearate solution and 7.81 g of an ethylcellulose solution. The viscosity of the composition C2 was 27.2 Pa immediately after preparation. s, after storage at 25 ° C for 30 days, 28.0Pa. s.

A passivation layer was formed on the tantalum substrate in the same manner as in Example 1 except that the composition C2 prepared above was used, and the evaluation was performed in the same manner. Of the 10 screen printings, 9 were not printed unevenly. In addition, among the 10 sheets, the coating film was uniform evenly. The effective life is 24μs.

<Comparative Example 4>

2.13 g of ruthenium chloride, 2.14 g of (ethyl acetoacetate) aluminum isopropoxide, and terpineol 1.79 g, 1.55 g of a decylamine stearate solution and 7.84 g of an ethylcellulose solution were mixed to prepare a composition C3. The viscosity of the composition C1 was 28.6 Pa after preparation. s, 58.4Pa after 30 days of storage at 25 ° C. s.

The above results are summarized in the table below.

In the storage stability item in the table, the change rate of the shear viscosity after 30 days of storage is marked as A, and the above change rate is 10% or more and less than 30% is marked as B, the above change rate Marked as C for more than 30%. When evaluated as A and B, the storage stability of the composition for forming a passivation layer was good.

In addition, in the printing property, the case where 9 or more of the 10 sheets are not printed in the printing is marked as A, and 8 or less and 6 or more are marked as B, and 5 or less. The condition is marked as C.

In addition, in the uniformity of the coating film, the case where the coating film is uniform after printing is 9 or more in 10 sheets is marked as A, and 8 or less and 6 or more sheets are marked as B and 5 or less. The condition is marked as C.

As described above, the composition for forming a passivation layer of the present invention is excellent in storage stability. Further, it has been found that by using the composition for forming a passivation layer of the present invention, a passivation layer having an excellent passivation effect can be formed. Further, it has been found that by using the composition for forming a passivation layer of the present invention, the passivation layer can be formed into a desired shape by a simple procedure. Further, it was found that the compositions for forming a passivation layer of Examples 1 to 3 were excellent in printability and coating film uniformity.

<Reference Embodiment 1>

The following is a passivation film, a coating material, a solar cell element, and a tantalum substrate with a passivation film according to the first embodiment.

<1> A passivation film containing aluminum oxide and cerium oxide for use in a solar cell element having a ruthenium substrate.

<2> The passivation film according to <1>, wherein a mass ratio of the cerium oxide to the aluminum oxide (cerium oxide/alumina) is 30/70 to 90/10.

<3> The passivation film according to <1>, wherein the total content of the cerium oxide and the aluminum oxide is 90% by mass or more.

The passivation film of any one of <1> to <3> further contains an organic component.

The passivation film according to any one of <1> to <4> which is a heat-treated material of a coating material containing an alumina precursor and a cerium oxide precursor.

<6> A coating type material comprising an alumina precursor and a cerium oxide precursor for forming a passivation film of a solar cell element having a ruthenium substrate.

<7> A solar cell element comprising: The p-type germanium substrate includes a single crystal germanium or a polycrystalline germanium, and has a light receiving surface and a back surface opposite to the light receiving surface; the n-type impurity diffusion layer is formed on the light receiving surface side of the germanium substrate; and the first electrode is formed on the germanium substrate a surface of the n-type impurity diffusion layer on the light-receiving surface side of the substrate; a passivation film formed on a surface on the back surface side of the ruthenium substrate, having a plurality of openings, containing aluminum oxide and ruthenium oxide, and a second electrode; Electrical connection is formed to the surface on the back side of the tantalum substrate via the plurality of openings.

<8> A solar cell element comprising: a p-type germanium substrate comprising a single crystal germanium or a polycrystalline germanium, having a light receiving surface and a back surface opposite to the light receiving surface; and an n-type impurity diffusion layer formed on the light receiving surface of the germanium substrate a first electrode formed on a surface of the n-type impurity diffusion layer on a light-receiving surface side of the ruthenium substrate; and a p-type impurity diffusion layer formed on a part or all of a back surface side of the ruthenium substrate An impurity is added to a higher concentration of the substrate; the passivation film is formed on a surface on the back surface side of the ruthenium substrate, has a plurality of openings, and contains aluminum oxide and ruthenium oxide; and the second electrode passes through the plurality of openings The surface of the p-type impurity diffusion layer on the back side of the tantalum substrate is electrically connected.

<9> A solar cell component having: The n-type germanium substrate includes a single crystal germanium or a polycrystalline germanium, and has a light receiving surface and a back surface opposite to the light receiving surface; a p-type impurity diffusion layer is formed on the light receiving surface side of the germanium substrate; and a second electrode is formed on the germanium substrate a passivation film formed on the surface on the light-receiving surface side of the ruthenium substrate, having a plurality of openings and containing aluminum oxide and ruthenium oxide; and a first electrode formed on the light-receiving surface side of the ruthenium substrate The surface of the p-type impurity diffusion layer is electrically connected to the surface of the germanium substrate on the light-receiving surface side via the plurality of openings.

The solar cell element according to any one of <7> to <9> wherein the mass ratio of cerium oxide to aluminum oxide in the passivation film (yttria/alumina) is 30/70 to 90/10. .

The solar cell element according to any one of the above aspects, wherein the total content of the cerium oxide and the aluminum oxide in the passivation film is 90% by mass or more.

<12> A ruthenium substrate having a passivation film, comprising: a ruthenium substrate; and a passivation film according to any one of <1> to <5>, which is provided on the entire surface or a part of the ruthenium substrate.

According to the above-described reference embodiment, the passivation film which has a carrier life of the ruthenium substrate and has a negative fixed charge can be realized at low cost. In addition, a coating type material for realizing the formation of the passivation film can be provided. In addition, it can be realized at low cost. A highly efficient solar cell element using the passivation film. In addition, a germanium substrate with a passivation film which has a long carrier life and a negative fixed charge can be realized at low cost.

The passivation film of this embodiment is a passivation film used for a tantalum solar cell element, and contains aluminum oxide and ruthenium oxide.

Further, in the present embodiment, the amount of fixed charge of the film can be controlled by changing the composition of the passivation film.

Further, from the viewpoint of stabilizing the negative fixed charge, it is more preferable that the mass ratio of cerium oxide to aluminum oxide is 30/70 to 80/20. Further, from the viewpoint of making the negative fixed charge more stable, it is preferable that the mass ratio of cerium oxide to aluminum oxide is 35/65 to 70/30. Further, from the viewpoint of improving the life of the carrier and the negative fixed charge, the mass ratio of cerium oxide to aluminum oxide is preferably 50/50 to 90/10.

The mass ratio of cerium oxide to aluminum oxide in the passivation film can be determined by Energy Dispersive X-ray spectroscope (EDX), Secondary Ion Mass Spectrometer (SIMS) and high frequency. Inductively coupled plasma-mass spectrometry (ICP-MS) was used for the determination. The specific measurement conditions are as follows. Dissolving the passivation film in an acid or alkaline aqueous solution, forming the solution into a mist and introducing it into the Ar plasma, and splitting the light emitted by the excited element back to the ground state to measure the wavelength and intensity, according to the obtained The wavelength is used to characterize the element, and the amount is quantified based on the obtained intensity.

The total content of cerium oxide and aluminum oxide in the passivation film is preferably 80% by mass or more, and more preferably 90% by mass or more from the viewpoint of maintaining good characteristics. When the components of cerium oxide and aluminum oxide in the passivation film are increased, the effect of negatively fixing charges becomes large.

The total content of cerium oxide and aluminum oxide in the passivation film can be determined by combining thermogravimetric analysis, fluorescent X-ray analysis, ICP-MS, and X-ray absorption spectroscopy. The specific measurement conditions are as follows. The ratio of the inorganic component was calculated by thermogravimetric analysis, and the ratio of cerium to aluminum was calculated by fluorescence X-ray or ICP-MS analysis, and the ratio of the oxide was examined by X-ray absorption spectroscopy.

Further, in the passivation film, from the viewpoint of improving the film quality or adjusting the elastic modulus, components other than cerium oxide and aluminum oxide can be contained in the form of an organic component. The presence of the organic component in the passivation film can be confirmed by elemental analysis and Fourier transform infrared spectroscopy (FT-IR) measurement of the film.

The content of the organic component in the passivation film is more preferably less than 10% by mass in the passivation film, further preferably 5% by mass or less, and particularly preferably 1% by mass or less.

The passivation film can also be obtained in the form of a heat-treated product of a coating type material containing an alumina precursor and a cerium oxide precursor. The coating type material will be described in detail below.

The coating material of the present embodiment contains an alumina precursor and a cerium oxide precursor, and is used to form a passivation film for a solar cell element having a ruthenium substrate.

The alumina precursor can be used without particular limitation as long as it forms alumina. The alumina precursor preferably uses an organic alumina precursor in terms of uniform dispersion of alumina on the tantalum substrate and chemical stability. Examples of the organic alumina precursor include aluminum triisopropoxide (structure: Al(OCH(CH ₃ ) ₂ ) ₃ ), SYM-AL04 of the Institute of High Purity Chemicals, etc. .

The cerium oxide precursor can be used without particular limitation as long as it forms cerium oxide. From the viewpoint of uniformly dispersing cerium oxide on the cerium substrate and chemical stability, the cerium oxide precursor is preferably an organic cerium oxide precursor. Examples of the organic cerium oxide precursor include cerium (V) (structural formula: Nb(OC ₂ H ₅ ) ₅ , molecular weight: 318.21), and Nb-05 of the High Purity Chemical Research Institute.

A coating type material containing an organic cerium oxide precursor and an organic alumina precursor is formed into a film by a coating method or a printing method, and the organic component is removed by heat treatment (calcination) thereafter. Passivation film. Therefore, the passivation film can also be a passivation film containing an organic component.

<Structure Description of Solar Cell Components>

The structure of the solar cell element of the present embodiment will be described with reference to Figs. 5 to 8 . 5 to 8 are cross-sectional views showing a first configuration example to a fourth configuration example of a solar battery element using a passivation film on the back surface of the embodiment.

As the tantalum substrate (crystalline germanium substrate, semiconductor substrate) 101 used in the present embodiment, any of single crystal germanium or polycrystalline germanium can be used. Further, as the tantalum substrate 101, any of a crystalline germanium having a p-type conductivity type or a crystalline germanium having a conductivity type n-type can be used. From the viewpoint of further exerting the effects of the present embodiment, it is more preferable that the conductivity type is a p-type crystal ruthenium.

In the following FIGS. 5 to 8, an example in which a p-type single crystal germanium is used as the germanium substrate 101 will be described. In addition, the single crystal germanium or polycrystalline germanium used in the germanium substrate 101 may be any, preferably having a resistivity of 0.5 Ω. Cm~10Ω. Cm single crystal germanium or polycrystalline germanium.

As shown in FIG. 5 (the first configuration example), an n-type diffusion layer 102 doped with a group V element such as phosphorus is formed on the light-receiving surface side (upper side, first surface) of the p-type germanium substrate 101. Further, a pn junction is formed between the germanium substrate 101 and the diffusion layer 102. On the surface of the diffusion layer 102, a light-receiving surface anti-reflection film 103 such as a tantalum nitride (SiN) film or a first electrode 105 (such as an electrode on the light-receiving surface side, a first surface electrode, and an upper surface) using silver (Ag) or the like is formed. Surface electrode, light receiving surface electrode). The light-receiving surface anti-reflection film 103 can also function as a light-receiving surface passivation film. By using the SiN film, both the function of the light-receiving surface anti-reflection film and the light-receiving surface passivation film can be achieved.

Further, the solar cell element of the present embodiment may have the light-receiving surface anti-reflection film 103 or may not have the light-receiving surface anti-reflection film 103. Further, in order to reduce the reflectance of the surface on the light-receiving surface of the solar cell element, it is preferable to form a concavo-convex structure (texture structure), and the solar cell element of the present embodiment may have a textured structure or may have no texture structure.

On the other hand, a back surface field (BSF) layer which is a layer doped with a group III element such as aluminum or boron is formed on the back side (the lower side, the second surface, and the back surface of the substrate) 101. 104. However, the solar cell element of the present embodiment may have the BSF layer 104 or may not have the BSF layer 104.

On the back side of the germanium substrate 101, in order to interact with the BSF layer 104 (not present) In the case of the BSF layer 104, the surface of the back surface side of the ruthenium substrate 101 is in contact with each other (electrically connected), and the second electrode 106 (electrode on the back side, second surface electrode, and back surface electrode) made of aluminum or the like is formed.

Then, in FIG. 5 (the first configuration example), a contact region electrically connected to the second electrode 106 is provided in addition to the BSF layer 104 (the surface on the back side of the substrate 101 when the BSF layer 104 is not present). A passivation film (passivation layer) 107 containing aluminum oxide and cerium oxide is formed in a portion other than the opening OA). The passivation film 107 of the present embodiment may have a negative fixed charge. By this fixed electric charge, electrons, which are a minority carrier in the carrier generated in the crucible substrate 101 by light, are reflected back to the surface side. Therefore, the short-circuit current is increased, and the photoelectric conversion efficiency can be expected to be improved.

Next, a second configuration example shown in FIG. 6 will be described. In FIG. 5 (first configuration example), the second electrode 106 is formed on the entire surface of the contact region (opening portion OA) and the passivation film 107, and in FIG. 6 (second configuration example), only the contact is made. The second electrode 106 is formed in the region (opening OA). It is also possible to adopt a configuration in which the second electrode 106 is formed on only a part of the contact region (opening OA) and the passivation film 107. Even in the solar cell element having the configuration shown in Fig. 6, the same effects as those in Fig. 5 (the first configuration example) can be obtained.

Next, a third configuration example shown in FIG. 7 will be described. In the third configuration example shown in FIG. 7, the BSF layer 104 is formed on only a part of the back surface side including the contact region (the opening portion OA portion) of the second electrode 106, instead of FIG. 5 (the first configuration) Example) is formed on the entire surface on the back side. Even in the solar cell element (FIG. 7) having such a configuration, the same effects as those of FIG. 5 (the first configuration example) can be obtained. another In addition, according to the solar cell element of the third configuration example of FIG. 7, the BSF layer 104 is doped with a group III element such as aluminum or boron, and a region having a higher concentration than the germanium substrate 101 is doped with impurities. Photoelectric conversion efficiency higher than that of Fig. 5 (first configuration example) can be obtained.

Next, a fourth configuration example shown in FIG. 8 will be described. In FIG. 7 (the third configuration example), the second electrode 106 is formed on the entire surface of the contact region (opening portion OA) and the passivation film 107, and in FIG. 8 (fourth configuration example), only the contact is made. The second electrode 106 is formed in the region (opening OA). It is also possible to adopt a configuration in which the second electrode 106 is formed on only a part of the contact region (opening OA) and the passivation film 107. Even in the solar cell element having the configuration shown in Fig. 8, the same effects as those in Fig. 7 (the third configuration example) can be obtained.

In addition, when the second electrode 106 is applied by a printing method and is formed on the entire surface on the back side by firing at a high temperature, warping of the upward convexity is likely to occur during the temperature lowering process. Such warpage sometimes causes damage to the solar cell components, and the yield may be lowered. In addition, the problem of warpage during the development of the thin film of the tantalum substrate becomes large. The reason for this warpage is that the second electrode 106 including a metal (for example, aluminum) has a thermal expansion coefficient larger than that of the tantalum substrate, and thus the shrinkage during the cooling process is large, so that stress is generated.

According to the above, when the second electrode 106 is not formed on the entire surface on the back side as shown in FIG. 6 (the second configuration example) and FIG. 8 (the fourth configuration example), the electrode structure is likely to be vertically symmetrical and is less likely to be generated. The stress caused by the difference in thermal expansion coefficient is therefore preferred. In this case, it is preferable to further provide a reflective layer.

<Method of Manufacturing Solar Cell Components>

Next, an example of a method of manufacturing the solar cell element (Figs. 5 to 8) of the present embodiment having the above configuration will be described. However, the present embodiment is not limited to the solar cell element produced by the method described below.

First, a texture structure is formed on the surface of the ruthenium substrate 101 shown in FIG. 5 and the like. The formation of the texture structure may be formed on both surfaces of the ruthenium substrate 101, or may be formed only on one side (the light-receiving surface side). In order to form a texture structure, the tantalum substrate 101 is first immersed in a solution of heated potassium hydroxide or sodium hydroxide to remove the damaged layer of the tantalum substrate 101. Thereafter, it is immersed in a solution containing potassium hydroxide and isopropyl alcohol as a main component, whereby a texture structure is formed on both surfaces or one side (light-receiving surface side) of the ruthenium substrate 101. Further, as described above, the solar cell element of the present embodiment may have a textured structure or a textured structure, and this step may be omitted.

Then, after the ruthenium substrate 101 is washed with a solution such as hydrochloric acid or hydrofluoric acid, a phosphorus diffusion layer (n ⁺ layer) as the diffusion layer 102 is formed on the ruthenium substrate 101 by thermal diffusion of phosphorus oxychloride (POCl ₃ ) or the like. ). The phosphorus diffusion layer can be formed, for example, by applying a solution of a coating type doping material containing phosphorus to the ruthenium substrate 101 and performing heat treatment. After the heat treatment, the phosphorus glass layer formed on the surface is removed by an acid such as hydrofluoric acid, thereby forming a phosphorus diffusion layer (n ⁺ layer) as the diffusion layer 102. The method of forming the phosphorus diffusion layer is not particularly limited. The phosphorus diffusion layer is preferably formed so that the depth from the surface of the ruthenium substrate 101 is in the range of 0.2 μm to 0.5 μm, and the sheet resistance is in the range of 40 Ω/□ to 100 Ω/□ (ohm/square).

Thereafter, a solution containing a coating type doping material such as boron or aluminum is applied to the back surface side of the tantalum substrate 101, and heat treatment is performed to form the BSF layer 104 on the back side. At the time of application, methods such as screen printing, inkjet, dispensing, and spin coating can be used. After the heat treatment, a layer such as borosilicate glass or aluminum formed on the back surface is removed by hydrofluoric acid, hydrochloric acid or the like to form the BSF layer 104. The method of forming the BSF layer 104 is not particularly limited. It is preferable that the BSF layer 104 is formed in such a manner that the concentration of boron, aluminum, or the like is in the range of 10 ¹⁸ cm ^-3 to 10 ²² cm ^-3 , and it is preferable to form the BSF layer 104 in a dot shape or a line shape. . Further, the solar cell element of the present embodiment may have the BSF layer 104 or may not have the BSF layer 104, and this step may be omitted.

Further, when the diffusion layer 102 on the light-receiving surface and the BSF layer 104 on the back surface are formed using a solution of a coating-type dopant, the solution of the dopant may be applied to the substrate 101, respectively. On both sides, a phosphorus diffusion layer (n ⁺ layer) as the diffusion layer 102 is formed together with the BSF layer 104, and thereafter phosphorus glass, borosilicate glass or the like formed on the surface is removed together.

Thereafter, a tantalum nitride film as the light-receiving surface anti-reflection film 103 is formed on the diffusion layer 102. The method of forming the light-receiving surface anti-reflection film 103 is not particularly limited. The light-receiving surface anti-reflection film 103 is preferably formed to have a thickness in the range of 50 nm to 100 nm and a refractive index of 1.9 to 2.2. The light-receiving surface anti-reflection film 103 is not limited to the tantalum nitride film, and may be a hafnium oxide film, an aluminum oxide film, a titanium oxide film or the like. The surface anti-reflection film 103 such as a tantalum nitride film can be formed by plasma CVD, thermal CVD, or the like, and is preferably formed by plasma CVD which can form the surface anti-reflection film 103 in a temperature range of 350 ° C to 500 ° C. Antireflection film 103.

Then, a passivation film 107 is formed on the back side of the germanium substrate 101. The passivation film 107 contains aluminum oxide and cerium oxide, for example, by imparting the following materials (passivation materials) And formed by heat treatment (calcination), the material (passivation material) contains an alumina precursor represented by an organometallic decomposition coating material which can be obtained by heat treatment (calcination), and can be heat treated (calcined) A cerium oxide precursor represented by a commercially available organometallic decomposition coating type material of cerium oxide is obtained.

The formation of the passivation film 107 can be performed, for example, as follows. The coated material was spin-coated on a single side of a 8 吋 (20.32 cm) p-type ruthenium substrate (8 Ω cm to 12 Ω cm) having a thickness of 725 μm in which the natural oxide film was 725 μm, which was previously removed by using hydrofluoric acid having a concentration of 0.049% by mass. The prebaking was carried out on a hot plate at 120 ° C for 3 minutes. Thereafter, heat treatment was performed at 650 ° C for 1 hour under a nitrogen atmosphere. In this case, a passivation film containing aluminum oxide and cerium oxide can be obtained. The film thickness of the passivation film 107 formed by the method described above by an ellipsometer is usually about several tens of nanometers (nm).

The coating material is applied to a predetermined pattern including a contact region (opening OA) by a method such as screen printing, pattern printing, inkjet printing, or printing by a dispenser. Further, it is preferable that the coating material is prebaked in a range of from 80 ° C to 180 ° C after the application, and the solvent is evaporated, and then subjected to a nitrogen atmosphere or air at 600 ° C to 1000 ° C for 30 minutes. Heat treatment (annealing) for about 3 hours to form a passivation film 107 (film of an oxide).

Further, the opening (hole for contact) OA is preferably formed on the BSF layer 104 in a dot shape or a line shape.

The passivation film 107 used in the above solar cell element preferably has a mass ratio of cerium oxide to aluminum oxide (yttria/alumina) of 30/70 to 90/10, more preferably 30/70. ~80/20, and then the best is 35/65~70/30. Thereby, the negative fixed charge can be stabilized. Further, from the viewpoint of improving the life of the carrier and the negative fixed charge, the mass ratio of cerium oxide to aluminum oxide is preferably 50/50 to 90/10.

Further, in the passivation film 107, the total content of cerium oxide and aluminum oxide is preferably 80% by mass or more, and more preferably 90% by mass or more.

Then, the first electrode 105 which is an electrode on the light-receiving surface side is formed. The first electrode 105 is formed by forming a paste containing silver (Ag) as a main component on the light-receiving surface anti-reflection film 103 by screen printing, and performing heat treatment (burn-through). The shape of the first electrode 105 may be any shape, and may be, for example, a well-known shape including a finger electrode and a bus bar electrode.

Then, the second electrode 106 which is an electrode on the back side is formed. The second electrode 106 is formed by applying a paste containing aluminum as a main component using a screen printing or a dispenser, and heat-treating the same. Further, the shape of the second electrode 106 is preferably the same shape as that of the BSF layer 104, the shape of the entire surface covering the back surface side, a comb shape, a lattice shape, or the like. In addition, printing of the paste for forming the first electrode 105 and the second electrode 106 as electrodes on the light-receiving surface side may be performed first, and then heat treatment (burn-through) may be performed to form the first electrode 105 and the second electrode together. Electrode 106.

Further, when the second electrode 106 is formed, aluminum is diffused as a dopant by using a paste containing aluminum (Al) as a main component, and the contact portion between the second electrode 106 and the ruthenium substrate 101 is self-aligned. A BSF layer 104 is formed. Further, as described above, a coating type doping containing boron, aluminum, or the like may be imparted to the back side of the ruthenium substrate 101. A solution of the miscellaneous material is subjected to heat treatment, thereby further forming a BSF layer 104.

Further, the above shows a configuration example and a manufacturing example in which a p-type germanium is used for the germanium substrate 101, and an n-type germanium substrate can be used as the germanium substrate 101. In this case, the diffusion layer 102 is formed by a layer doped with a group III element such as boron, and the BSF layer 104 is formed by doping a group V element such as phosphorus. In this case, it is necessary to pay attention to the fact that the negative electrode formed on the interface and the portion in contact with the metal on the back side communicate with each other and the leakage current flows, and the conversion efficiency is hard to be improved.

Further, in the case of using an n-type germanium substrate, the passivation film 107 containing cerium oxide and aluminum oxide can be used for the light-receiving surface side as shown in FIG. FIG. 9 is a cross-sectional view showing a configuration example of a solar cell element using the light-receiving surface passivation film of the embodiment.

In this case, the diffusion layer 102 on the light-receiving surface side is doped with boron to form a p-type, and the holes in the generated carriers are collected on the light-receiving surface side, and electrons are collected on the back surface side. Therefore, it is preferable that the passivation film 107 having a negative fixed charge is located on the light receiving surface side.

An antireflection film made of SiN or the like may be further formed on the passivation film containing cerium oxide and aluminum oxide by CVD or the like.

Hereinafter, the reference embodiment and the reference comparative example of the present embodiment will be described in detail.

[Reference Example 1-1]

A commercially available organometallic decomposition coating material which can obtain alumina (Al ₂ O ₃ ) by heat treatment (calcination) [SYM-AL04 of High Purity Chemical Research Institute Co., Ltd., concentration: 2.3% by mass] 3.0 g, a commercially available organometallic decomposition coating material which can obtain cerium oxide (Nb ₂ O ₅ ) by heat treatment (calcination) [Nb-05 of High Purity Chemical Research Institute Co., Ltd., concentration: 5% by mass ] 3.0 g was mixed to prepare a passivation material (a-1) as a coating type material.

The passivation material (a-1) was spin-coated on a single surface of an 8-inch p-type tantalum substrate (8 Ωcm to 12 Ωcm) having a thickness of 725 μm of a natural oxide film removed by using hydrofluoric acid having a concentration of 0.049% by mass. Prebaking was carried out on a hot plate at 120 ° C for 3 minutes. Thereafter, heat treatment (calcination) was carried out at 650 ° C for 1 hour in a nitrogen atmosphere to obtain a passivation film containing alumina and cerium oxide [cerium oxide/alumina = 68/32 (mass ratio)]. The film thickness was measured by an ellipsometer and found to be 43 nm. The FT-IR of the passivation film was measured, and as a result, a very weak peak derived from an alkyl group was observed in the vicinity of 1200 cm ^-1 .

Then, on the passivation film, a plurality of aluminum electrodes having a diameter of 1 mm were formed by vapor deposition in the metal mask to form a capacitor of a metal-insulator-semiconductor (MIS) structure. The voltage dependence (CV characteristic) of the capacitance of the capacitor was measured by a commercially available prober and an LCR meter (HP company, 4275A). The results show that the flat band voltage (Vfb) is shifted from the ideal value of -0.81V to +0.32V. From the amount of movement, it was found that the passivation film obtained from the passivation material (a-1) showed a fixed charge having a fixed charge density (Nf) of -7.4 × 10 ¹¹ cm ^-2 and a negative value.

In the same manner as described above, the passivation material (a-1) was applied to both surfaces of a p-type ruthenium substrate of 8 Å, prebaked, and heat-treated (calcined) at 650 ° C for 1 hour in a nitrogen atmosphere to prepare a ruthenium substrate. A sample covered on both sides by a passivation film. With the life measuring device (Kobelco Research Institute shares have Limited company, RTA-540) to determine the carrier lifetime of these samples. The resulting carrier lifetime was 530 μs. For comparison, the same 8-inch p-type ruthenium substrate was passivated and measured by iodine passivation, and the carrier lifetime was 1100 μs.

From the above, it is known that the passivation film obtained by subjecting the passivation material (a-1) to heat treatment (calcination) exhibits a certain degree of passivation performance and exhibits a negative fixed charge.

[Reference Example 1-2]

In the same manner as in Reference Example 1-1, a commercially available organometallic decomposition coating material which can be obtained by heat treatment (calcination) of alumina (Al ₂ O ₃ ) [High Purity Chemical Research Institute Co., Ltd., SYM -AL04, a concentration of 2.3% by mass], and a commercially available organometallic decomposition coating material capable of obtaining cerium oxide (Nb ₂ O ₅ ) by heat treatment (calcination) [High Purity Chemical Research Institute Co., Ltd., Nb -05, the concentration was 5% by mass], and the ratio was changed and mixed, and the passivation material (a-2) to passivation material (a-7) shown in Table 2 was prepared.

In the same manner as in Reference Example 1-1, the passivation material (a-2) to the passivation material (a-7) were respectively applied to one surface of the p-type germanium substrate, and heat treatment (calcination) was performed to prepare a passivation film. The voltage dependence of the capacitance of the obtained passivation film was measured, and the fixed charge density was calculated based on this.

Further, in the same manner as in Reference Example 1-1, a passivation material was applied to both surfaces of the p-type ruthenium substrate, and heat treatment (calcination) was performed, and the obtained sample was used to measure the carrier lifetime. The results obtained are summarized in Table 2.

Depending on the ratio (mass ratio) of cerium oxide/alumina after heat treatment (calcination), the results are different, but regarding passivation material (a-2) to passivation material (a-7), After the heat treatment (calcination), the carrier lifetime also shows a certain value, so it is suggested to function as a passivation film. It is known that the passivation film obtained from the passivation material (a-2) to the passivation material (a-7) stably exhibits a negative fixed charge, and can also be preferably used as a passivation film of a p-type germanium substrate.

[Reference Example 1-3]

Commercially available ruthenium (V) (structural formula: Nb(OC ₂ H ₅ ) ₅ , molecular weight: 318.21) 3.18 g (0.010 mol), commercially available aluminum triisopropoxide (structural formula: Al (OCH (CH) ₃ ) ₂ ) ₃ , molecular weight: 204.25) 1.02 g (0.005 mol) was dissolved in 80 g of cyclohexane to prepare a passivation material (c-1) having a concentration of 5 mass%.

The passivation material (c-1) was spin-coated on a single surface of an 8-inch p-type tantalum substrate (8 Ωcm to 12 Ωcm) having a thickness of 725 μm of a natural oxide film removed by using hydrofluoric acid having a concentration of 0.049% by mass. Prebaking was carried out on a hot plate at 120 ° C for 3 minutes. Thereafter, heat treatment (calcination) was performed at 600 ° C for 1 hour in a nitrogen atmosphere to obtain a passivation film containing aluminum oxide and cerium oxide. The film thickness was measured by an ellipsometer and found to be 50 nm. As a result of performing elemental analysis, it was found that Nb/Al/C = 81/14/5 (% by mass). The FT-IR of the passivation film was measured, and as a result, a very weak peak derived from an alkyl group was observed in the vicinity of 1200 cm ^-1 .

Then, on the passivation film, a plurality of aluminum electrodes having a diameter of 1 mm were formed by vapor deposition in the metal mask to form a capacitor of a metal-insulator-semiconductor (MIS) structure. The voltage dependence (CV characteristic) of the capacitance of the capacitor was measured by a commercially available prober and an LCR meter (HP company, 4275A). The results show that the flat band voltage (Vfb) is shifted from the ideal value of -0.81V to +4.7V. From the amount of movement, it was found that the passivation film obtained from the passivation material (c-1) exhibited a fixed charge having a fixed charge density (Nf) of -3.2 × 10 ¹² cm ^-2 and a negative value.

In the same manner as described above, the passivation material (c-1) was applied to both surfaces of a p-type ruthenium substrate of 8 Å, prebaked, and heat-treated (calcined) at 600 ° C for 1 hour in a nitrogen atmosphere to prepare a ruthenium substrate. A sample covered by a passivation film on both sides. The measurement of the carrier lifetime of these samples was carried out by a life measuring device (Kobelco Research Institute Co., Ltd., RTA-540). The resulting carrier lifetime was 330 μs. For comparison, the same 8-inch p-type ruthenium substrate was passivated and measured by iodine passivation, and the carrier lifetime was 1100 μs.

From the above, it is known that the passivation film obtained by subjecting the passivation material (c-1) to heat treatment (calcination) exhibits a certain degree of passivation performance and exhibits a negative fixed charge.

[Reference Examples 1-4]

Commercially available ruthenium (V) (structural formula: Nb(OC ₂ H ₅ ) ₅ , molecular weight: 318.21) 2.35 g (0.0075 mol), commercially available aluminum triisopropoxide (structural formula: Al (OCH (CH) ₃ ) ₂ ) ₃ , molecular weight: 204.25) 1.02 g (0.005 mol), 10 g of novolak resin was dissolved in 10 g of diethylene glycol monobutyl ether acetate and 10 g of cyclohexane to prepare a passivation material (c-2).

The passivation material (c-2) was spin-coated on a single surface of an 8-inch p-type ruthenium substrate (8 Ωcm to 12 Ωcm) having a thickness of 725 μm of a natural oxide film removed by using hydrofluoric acid having a concentration of 0.049% by mass. Prebaking was carried out on a hot plate at 120 ° C for 3 minutes. Thereafter, heat treatment (calcination) was performed at 600 ° C for 1 hour in a nitrogen atmosphere to obtain a passivation film containing aluminum oxide and cerium oxide. The film thickness was measured by an ellipsometer and found to be 14 nm. As a result of elemental analysis, Nb/Al/C = 75/17/8 (% by mass) was obtained. The FT-IR of the passivation film was measured, and as a result, a very weak peak derived from an alkyl group was observed in the vicinity of 1200 cm ^-1 .

Then, on the passivation film, a plurality of aluminum electrodes having a diameter of 1 mm were formed by vapor deposition through a metal mask to form a capacitor of a metal-insulator-semiconductor (MIS) structure. The voltage dependence (CV characteristic) of the capacitance of the capacitor was measured by a commercially available prober and an LCR meter (HP company, 4275A). The results show that the flat band voltage (Vfb) is shifted from the ideal value of -0.81V to +0.10V. From the amount of movement, it was found that the passivation film obtained from the passivation material (c-2) showed a fixed charge having a fixed charge density (Nf) of -0.8 × 10 ¹¹ cm ^-2 and a negative value.

In the same manner as described above, the passivation material (c-2) was applied to both surfaces of a p-type ruthenium substrate of 8 Å, prebaked, and subjected to a nitrogen atmosphere at 600 ° C for 1 hour. Heat treatment (calcination), and a sample covered with a passivation film on both sides of the tantalum substrate was prepared. The measurement of the carrier lifetime of the sample was carried out by a life measuring device (Kobelco Research Institute Co., Ltd., RTA-540). The resulting carrier lifetime was 200 μs. For comparison, the same 8-inch p-type ruthenium substrate was passivated and measured by iodine passivation, and the carrier lifetime was 1100 μs.

From the above, it is known that the passivation film obtained from the passivation material (c-2) exhibits a certain degree of passivation performance and exhibits a negative fixed charge.

[Reference Examples 1-5 and Reference Comparative Example 1-1]

In the same manner as in Reference Example 1-1, a commercially available organometallic decomposition coating material which can obtain alumina (Al ₂ O ₃ ) by heat treatment (calcination) [SYM of High Purity Chemical Research Institute Co., Ltd.] -AL04, a concentration of 2.3% by mass], and a commercially available organometallic decomposition coating material capable of obtaining cerium oxide (Nb ₂ O ₅ ) by heat treatment (calcination) [Nb of High Purity Chemical Research Institute Co., Ltd. -05, a concentration of 5% by mass] was mixed and changed, and the passivation material (b-1) to passivation material (b-7) shown in Table 3 was prepared.

In the same manner as in Reference Example 1-1, the passivation material (b-1) to the passivation material (b-7) were respectively applied to one surface of the p-type germanium substrate, and heat treatment (calcination) was performed to prepare a passivation film. The passivation film measures the voltage dependence of the electrostatic capacitance, and calculates the fixed charge density based on this.

Further, in the same manner as in Reference Example 1-1, a passivation material (coating type material) was applied to both surfaces of the p-type ruthenium substrate, and the carrier life was measured using the cured sample. The results obtained are summarized in Table 3.

It is known that the passivation film obtained from the passivation material (b-1) to the passivation material (b-6) has a large carrier life and functions as a passivation. Further, in the case where the cerium oxide/alumina is 10/90 and 20/80, the value of the fixed charge density is largely deviated, and the negative fixed charge density cannot be stably obtained, but it can be confirmed that alumina and cerium oxide can be used. Achieve a negative fixed charge density. It has been found that when a passivation material having yttria/alumina of 10/90 and 20/80 is used for measurement by the CV method, it may become a passivation film which exhibits a positive fixed charge, and thus does not stably exhibit a negative fixation. Charge. Further, a passivation film exhibiting a positive fixed charge can be used as a passivation film of an n-type germanium substrate.

On the other hand, the passivation material (b-7) in which the alumina reaches 100% by mass cannot obtain a negative fixed charge density.

[Reference Comparative Example 1-2]

A commercially available organometallic decomposition coating material which can be obtained as a passivation material (d-1) by heat treatment (calcination) to obtain titanium oxide (TiO ₂ ) [Ti-03- of High Purity Chemical Research Institute Co., Ltd. P, a concentration of 3% by mass], a commercially available organometallic decomposition coating material capable of obtaining barium titanate (BaTiO ₃ ) by heat treatment (calcination) as a passivation material (d-2) [High Purity Chemistry Research] BT-06 of the company, a concentration of 6% by mass], and commercially available organometallic decomposition coating of lanthanum oxide (HfO ₂ ) which can be obtained by heat treatment (calcination) as a passivation material (d-3) Type material [Hf-05 of High Purity Chemical Research Institute Co., Ltd., concentration of 5% by mass].

In the same manner as in Reference Example 1-1, the passivation material (d-1) to the passivation material (d-3) were respectively applied to one surface of the p-type germanium substrate, and then heat treatment (calcination) was performed to prepare a passivation film. The passivation film measures the voltage dependence of the electrostatic capacitance, and calculates the fixed charge density based on this.

Further, in the same manner as in Reference Example 1-1, a passivation material was applied to both surfaces of the p-type ruthenium substrate, and a sample obtained by heat treatment (calcination) was used to measure the carrier lifetime. The results obtained are summarized in Table 4.

It is known that the passivation film obtained from the passivation material (d-1) to the passivation material (d-3) has a small carrier lifetime, and the function of passivation is insufficient. In addition, a positive fixed charge is shown. The passivation film obtained from the passivation material (d-3) has a negative fixed charge, but its value is small. In addition, the carrier lifetime is relatively small, and the function of passivation is insufficient.

[Reference Examples 1-6]

A solar cell element having the structure shown in Fig. 7 was produced by using a single crystal germanium substrate doped with boron as the germanium substrate 101. After the surface of the ruthenium substrate 101 is subjected to a texture treatment, a coating-type phosphorus diffusion material is applied to the light-receiving surface side, and a diffusion layer 102 (phosphorus diffusion layer) is formed by heat treatment. Thereafter, the coated phosphorus diffusion material was removed using dilute hydrofluoric acid.

Then, an SiN film formed by plasma CVD is formed on the light-receiving surface side as the light-receiving surface anti-reflection film 103. Thereafter, the passivation material (a-1) prepared in Reference Example 1-1 was applied to a region other than the contact region (opening portion OA) in the back surface side of the ruthenium substrate 101 by an inkjet method. Thereafter, heat treatment is performed to form a passivation film 107 having an opening OA.

Further, as the passivation film 107, a sample using the passivation material (c-1) prepared in Reference Example 1-3 was also prepared.

Then, on the light-receiving surface anti-reflection film 103 (SiN film) formed on the light-receiving surface side of the ruthenium substrate 101, a paste containing silver as a main component is screen-printed in the shape of a predetermined finger electrode and a bus bar electrode. On the back side, a paste with aluminum as a main component was screen printed onto the entire surface. Thereafter, heat treatment (burn-through) is performed at 850 ° C to form an electrode (first electrode 105 and second electrode 106), and aluminum is diffused into a portion of the opening OA of the back surface to form a BSF layer 104, and FIG. 7 is formed. The solar cell element of the structure shown.

In the silver electrode of the light-receiving surface, a burn-through step that does not open a hole in the SiN film is described. However, the opening portion OA may be formed in advance in the SiN film by etching or the like, and then a silver electrode may be formed.

For comparison, in the above-described fabrication step, the formation of the passivation film 107 is performed, and the aluminum paste is printed on the entire surface on the back side, and the p ⁺ layer 114 and the second electrode corresponding to the BSF layer 104 are formed on the entire surface. The corresponding electrode 116 forms a solar cell element having the structure shown in FIG. The solar cell elements were evaluated for characteristics (short circuit current, open circuit voltage, curve factor, and conversion efficiency). The evaluation of the characteristics was carried out in accordance with JIS-C-8913 (2005) and JIS-C-8914 (2005). The results are shown in Table 5.

As shown in Table 5, the solar cell element having the passivation film 107 containing the yttrium oxide and the aluminum oxide layer has an increase in the short-circuit current and the open circuit voltage, and the conversion efficiency (photoelectric conversion efficiency) is the largest as compared with the solar cell element having no passivation film 107. Increase by 1%.

<Reference Embodiment 2>

The following is a passivation film, a coating material, a solar cell element, and a tantalum substrate with a passivation film according to the second embodiment.

<1> A passivation film containing an oxide of at least one vanadium element selected from the group consisting of vanadium oxide and cerium oxide for use in having a ruthenium The solar cell component of the substrate.

<2> The passivation film according to <1>, wherein the mass ratio of the oxide of the vanadium group element to the aluminum oxide (the oxide of the vanadium group element/alumina) is 30/70 to 90/10.

<3> The passivation film according to <1>, wherein the total content of the oxide of the vanadium group element and the aluminum oxide is 90% or more.

The passivation film according to any one of <1> to <3> containing an oxide of two or three kinds of vanadium elements selected from the group consisting of vanadium oxide, cerium oxide and cerium oxide. It is an oxide of the above-mentioned vanadium group element.

The passivation film according to any one of <1> to <4> which is a heat-treated material of a coating material containing a precursor of alumina and a precursor selected from vanadium oxide. A precursor of an oxide of at least one vanadium element in the group consisting of precursors of cerium oxide and cerium oxide.

<6> a coating type material comprising a precursor of an alumina, a precursor of an oxide of at least one vanadium element selected from the group consisting of a precursor of vanadium oxide and a precursor of cerium oxide, and A passivation film for forming a solar cell element having a germanium substrate.

<7> A solar cell element comprising: a p-type germanium substrate; an n-type impurity diffusion layer formed on a first surface side of the light-receiving surface side of the germanium substrate; and a first electrode formed on the impurity diffusion layer; a passivation film formed on the second surface side opposite to the light-receiving surface side of the ruthenium substrate and having an opening; and a second electrode formed on the second surface side of the ruthenium substrate and passing through the opening of the passivation film The second surface side of the tantalum substrate is electrically connected; and the passivation film contains an oxide of at least one vanadium group element selected from the group consisting of vanadium oxide and niobium oxide.

<8> The solar cell element according to <7>, which has a p-type impurity diffusion layer formed on a part or all of the second surface side of the tantalum substrate, and is larger than the tantalum substrate Impurities are added to a higher concentration, and the second electrode is electrically connected to the p-type impurity diffusion layer through an opening of the passivation film.

<9> A solar cell element comprising: an n-type germanium substrate; a p-type impurity diffusion layer formed on a first surface side of the light-receiving surface side of the germanium substrate; a first electrode formed on the impurity diffusion layer; and passivation a film formed on the second surface side opposite to the light-receiving surface side of the ruthenium substrate and having an opening; and a second electrode formed on the second surface side of the ruthenium substrate and having the opening through the passivation film The second surface side of the germanium substrate is electrically connected; and the passivation film contains an oxide of at least one vanadium group element selected from the group consisting of vanadium oxide and cerium oxide.

<10> The solar cell element according to <9>, wherein the n-type impurity diffusion layer is formed on a part or all of the second surface side of the tantalum substrate, and is larger than the tantalum substrate. Impurities are added to a higher concentration, and the second electrode is electrically connected to the n-type impurity diffusion layer through an opening of the passivation film.

The solar cell element according to any one of the above aspects, wherein the mass ratio of the oxide of the vanadium group element to the aluminum oxide in the passivation film is 30/70 to 90/10.

The solar cell element according to any one of the above aspects of the present invention, wherein the total content of the oxide of the vanadium group element and the aluminum oxide of the passivation film is 90% or more.

The solar cell element according to any one of <7> to <12> containing oxidation of two or three kinds of vanadium elements selected from the group consisting of vanadium oxide, cerium oxide and cerium oxide. The substance acts as an oxide of the above vanadium group element.

<14> A solar cell element according to any one of <1> to <5>, wherein: Passivation film.

According to the above-described reference embodiment, the passivation film which has a carrier life of the ruthenium substrate and has a negative fixed charge can be realized at low cost. In addition, a coating type material for realizing the formation of the passivation film can be provided. In addition, a low-cost and highly efficient solar cell element using the passivation film can be realized. In addition, it can be implemented at low cost. A germanium substrate with a passivation film having a negative carrier lifetime and a negative fixed charge is now available.

The passivation film of the present embodiment is a passivation film used in a tantalum solar cell element, and contains an oxide of at least one vanadium group element selected from the group consisting of alumina oxide and cerium oxide.

Further, in the present embodiment, the amount of the fixed charge which the passivation film has can be controlled by changing the composition of the passivation film. Here, the vanadium group element refers to a group 5 element of the periodic table of elements, and is an element selected from the group consisting of vanadium, niobium and tantalum.

Further, from the viewpoint of stabilizing the negative fixed charge, the mass ratio of the oxide of the vanadium element to the alumina is preferably 35/65 to 90/10, and more preferably 50/50 to 90/10.

The mass ratio of the oxide of the vanadium group element to the aluminum oxide in the passivation film can be determined by energy dispersive X-ray spectroscopy (EDX), secondary ion mass spectrometry (SIMS), and high frequency inductively coupled plasma mass spectrometry ( ICP-MS) to determine. The specific measurement conditions are as follows, for example, in the case of ICP-MS. Dissolving the passivation film in an acid or alkaline aqueous solution, forming the solution into a mist and introducing it into the Ar plasma, and splitting the light emitted by the excited element back to the ground state to measure the wavelength and intensity, according to the obtained The wavelength is used to characterize the element, and the amount is quantified based on the obtained intensity.

The total content of the oxide of the vanadium group element and the aluminum oxide in the passivation film is preferably 80% by mass or more, and more preferably 90% by mass or more from the viewpoint of maintaining good characteristics. When the oxide of the vanadium group element and the components other than the alumina in the passivation film are increased, the effect of negatively fixing the charge becomes large.

Further, in the passivation film, from the viewpoint of improving the film quality and adjusting the elastic modulus, an oxide other than a vanadium element and a component other than alumina can be contained as an organic component. The presence of the organic component in the passivation film can be confirmed by elemental analysis and Fourier transform infrared spectroscopy (FT-IR) measurement of the film.

From the viewpoint of obtaining a larger negative fixed charge, the oxide of the above-mentioned vanadium element is preferably selected from vanadium oxide (V ₂ O ₅ ).

The passivation film may further contain, as an oxide of a vanadium group element, an oxide of two or three kinds of vanadium elements selected from the group consisting of vanadium oxide, cerium oxide, and cerium oxide.

The passivation film is preferably obtained by heat-treating a coating type material, and is more preferably obtained by coating a coating type material by a coating method or a printing method, and thereafter by heat treatment. Organic ingredients are removed. That is, the passivation film can also be obtained as a heat-treated product of a coating material containing a precursor of an oxide of an alumina precursor and an oxide of a vanadium group. The details of the coating material will be described later.

The coating material of the present embodiment is a coating material for a passivation film for a solar cell element having a ruthenium substrate, and includes a precursor of alumina and a precursor selected from a precursor of vanadium oxide and ruthenium oxide. A precursor of an oxide of at least one vanadium element in the constituent group. From the viewpoint of the negative fixed charge of the passivation film formed of the coating material, the precursor of the oxide of the vanadium element contained in the coating type material is preferably a precursor of selecting vanadium oxide (V ₂ O ₅ ). . The coating material may also contain a precursor of an oxide of two or three kinds of vanadium elements selected from the group consisting of a precursor of vanadium oxide, a precursor of cerium oxide, and a precursor of cerium oxide as a vanadium group. The precursor of the oxide of the element.

The alumina precursor can be used without particular limitation as long as it forms alumina. From the viewpoint of uniformly dispersing alumina on the ruthenium substrate and chemical stability, the alumina precursor is preferably an organic alumina precursor. Examples of the organic alumina precursors include aluminum triisopropoxide (structural formula: Al(OCH(CH ₃ ) ₂ ) ₃ ), and SYM-AL04 of the Institute of High Purity Chemicals.

The precursor of the oxide of the vanadium group element can be used without particular limitation as long as it forms an oxide of a vanadium group element. The precursor of the oxide of the vanadium group element is preferably a precursor of an oxide of an organic vanadium group element from the viewpoint of uniformly dispersing the alumina on the tantalum substrate and chemical stability.

Examples of the organic vanadium oxide precursor include vanadium oxyacetate (V) (structural formula: VO(OC ₂ H ₅ ) ₃ , molecular weight: 202.13), and V- of the High Purity Chemical Research Institute (share). 02. Examples of the precursor of the organic cerium oxide include methanol oxime (V) (structural formula: Ta(OCH ₃ ) ₅ , molecular weight: 336.12), and Ta-10-P of the High Purity Chemical Research Institute. Examples of the organic cerium oxide precursor include cerium (V) (structural formula: Nb(OC ₂ H ₅ ) ₅ , molecular weight: 318.21), and Nb-05 of the High Purity Chemical Research Institute.

A coating material containing an organic oxide-containing vanadium element oxide precursor and an organic alumina precursor coating film is formed by a coating method or a printing method, and the organic component is removed by heat treatment thereafter. This gives a passivation film. Therefore, the passivation film can also be a passivation film containing an organic component. Passive film of organic components The content is preferably less than 10% by mass, more preferably 5% by mass or less, and still more preferably 1% by mass or less.

The solar cell element (photoelectric conversion device) of the present embodiment has the passivation film (insulating film, protective insulating film) described in the above embodiment in the vicinity of the photoelectric conversion interface of the germanium substrate, that is, contains alumina, and is selected from vanadium oxide and a film of an oxide of at least one vanadium element in the group consisting of cerium oxide. By using an oxide containing at least one vanadium element selected from the group consisting of alumina and vanadium oxide and cerium oxide, the carrier life of the ruthenium substrate can be extended and a negative fixed charge can be obtained, thereby improving solar cell elements. Characteristics (photoelectric conversion efficiency).

The description of the structure and the manufacturing method of the solar cell element of the present embodiment can be referred to the description of the structure and the manufacturing method of the solar cell element according to the first embodiment.

Hereinafter, the reference embodiment and the reference comparative example of the present embodiment will be described in detail.

<Case of using vanadium oxide as an oxide of a vanadium group element>

[Reference Example 2-1]

A commercially available organometallic thin film coating type material which can obtain alumina (Al ₂ O ₃ ) by heat treatment (calcination) [High Purity Chemical Research Institute, SYM-AL04, concentration: 2.3% by mass] 3.0 g, a commercially available organometallic thin film coating type material capable of obtaining vanadium oxide (V ₂ O ₅ ) by heat treatment (calcination) [High Purity Chemical Research Institute, V-02, concentration 2% by mass ] 6.0 g of a mixture was used to prepare a passivation material (a2-1) as a coating type material.

The passivation material (a2-1) was spin-coated on a 8-inch p-type tantalum substrate (8 Ω.cm to 12 Ω.cm) having a thickness of 725 μm of a natural oxide film removed by using hydrofluoric acid having a concentration of 0.49% by mass in advance. On one side, it was placed on a hot plate and prebaked at 120 ° C for 3 minutes. Thereafter, heat treatment (calcination) was performed at 700 ° C for 30 minutes in a nitrogen atmosphere to obtain a passivation film containing alumina and vanadium oxide [vanadium oxide / alumina = 63 / 37 (% by mass)]. The film thickness was measured by an ellipsometer and found to be 51 nm. The FT-IR of the passivation film was measured, and as a result, a very weak peak derived from an alkyl group was observed in the vicinity of 1200 cm ^-1 .

Then, on the passivation film, a plurality of aluminum electrodes having a diameter of 1 mm were formed by vapor deposition to form a capacitor of a metal-insulator-semiconductor (MIS) structure. The voltage dependence (CV characteristic) of the capacitance of the capacitor was measured by a commercially available prober and an LCR meter (HP company, 4275A). The results show that the flat band voltage (Vfb) is shifted from the ideal value of -0.81V to +0.02V. From the amount of movement, it was found that the passivation film obtained from the passivation material (a2-1) exhibited a fixed charge having a fixed charge density (Nf) of -5.2 × 10 ¹¹ cm ^-2 and a negative value.

In the same manner as described above, the passivation material (a2-1) was applied to both surfaces of a 8 Å p-type ruthenium substrate, prebaked, and heat-treated (calcined) at 650 ° C for 1 hour in a nitrogen atmosphere to prepare ruthenium. A sample covered by a passivation film on both sides of the substrate. The carrier life of the sample was determined by a life measuring device (Kobelco Research Institute, RTA-540). The resulting carrier lifetime was 400 μs. For comparison, the same 8-inch p-type ruthenium substrate was passivated and measured by iodine passivation, and the carrier lifetime was 1100 μs. In addition, after making the sample, After 14 days, the carrier lifetime was measured again, and the resulting carrier lifetime was 380 μs. From this, it was found that the decrease in carrier lifetime (400 μs to 380 μs) was within -10%, and the decrease in carrier lifetime was small.

From the above, it is known that the passivation film obtained by heat-treating (calcining) the passivation material (a2-1) exhibits a certain degree of passivation performance and exhibits a negative fixed charge.

[Reference Example 2-2]

In the same manner as in Reference Example 2-1, a commercially available organometallic thin film coating type material (High Purity Chemical Research Institute, SYM) which can obtain alumina (Al ₂ O ₃ ) by heat treatment (calcination) is used. -AL04, a concentration of 2.3% by mass], and a commercially available organometallic thin film coating type material capable of obtaining vanadium oxide (V ₂ O ₅ ) by heat treatment [High Purity Chemical Research Institute, V-02, The passivation material (a2-2) to the passivation material (a2-7) shown in Table 6 were prepared by mixing at a concentration of 2% by mass.

In the same manner as in Reference Example 2-1, the passivation material (a2-2) to the passivation material (a2-7) were respectively applied onto one surface of the p-type germanium substrate, and heat-treated (calcined) to prepare a passivation film. The voltage dependence of the capacitance of the obtained passivation film was measured, and the fixed charge density was calculated based on this.

Then, a passivation material was applied onto both surfaces of the p-type ruthenium substrate in the same manner as in Reference Example 2-1, and heat treatment (calcination) was performed, and the obtained sample was used to measure the carrier lifetime.

The results obtained are summarized in Table 6. In addition, after 14 days from the preparation of the sample, the carrier life was measured again, and the use of the passivation material (a2-2) shown in Table 6 was obtained. ~ The passivation film of the passivation material (a2-7) has a carrier life reduction of -10% or less, and the carrier lifetime is reduced.

Depending on the ratio (mass ratio) of vanadium oxide/alumina after heat treatment (calcination), the results are different, but the passivation material (a2-2) to passivation material (a2-7) show a negative fixation after heat treatment (calcination). The charge and carrier lifetime also show a certain degree of value, so it is suggested to function as a passivation film. It is known that the passivation film obtained from the passivation material (a2-2) to the passivation material (a2-7) stably exhibits a negative fixed charge, and can also be preferably used as a passivation film of a p-type germanium substrate.

[Reference Example 2-3]

Commercially available vanadium oxyacetate (V) as a compound which can be obtained by heat treatment (calcination) to obtain vanadium oxide (V ₂ O ₅ ) (structural formula: VO(OC ₂ H ₅ ) ₃ , molecular weight: 202.13) 1.02 g (0.010 mol), and commercially available aluminum triisopropoxide as a compound which can be obtained by heat treatment (calcination) to obtain alumina (Al ₂ O ₃ ) (structural formula: Al(OCH(CH ₃ ) ₂ ) ₃ , molecular weight: 204.25) 2.04 g (0.010 mol) was dissolved in 60 g of cyclohexane to prepare a passivation material (b2-1) having a concentration of 5 mass%.

The passivation material (b2-1) was spin-coated on a 8-inch p-type tantalum substrate (8 Ω.cm to 12 Ω.cm) having a thickness of 725 μm of a natural oxide film removed by using hydrofluoric acid having a concentration of 0.49% by mass in advance. On one side, prebaking was carried out on a hot plate at 120 ° C for 3 minutes. Thereafter, heat treatment (calcination) was performed at 650 ° C for 1 hour in a nitrogen atmosphere to obtain a passivation film containing aluminum oxide and vanadium oxide. The film thickness was measured by an ellipsometer and found to be 60 nm. As a result of elemental analysis, it was found that V/Al/C = 64/33/3 (% by mass). The FT-IR of the passivation film was measured, and as a result, a very weak peak derived from an alkyl group was observed in the vicinity of 1200 cm ^-1 .

Then, on the passivation film, a plurality of aluminum electrodes having a diameter of 1 mm were formed by vapor deposition to form a capacitor of a metal-insulator-semiconductor (MIS) structure. The voltage dependence (CV characteristic) of the capacitance of the capacitor was measured by a commercially available prober and an LCR meter (HP company, 4275A). The results show that the flat band voltage (Vfb) is shifted from the ideal value of -0.81V to +0.10V. From the amount of movement, it was found that the passivation film obtained from the passivation material (b2-1) showed a fixed charge having a fixed charge density (Nf) of -6.2 × 10 ¹¹ cm ^-2 and a negative value.

The passivation material (b2-1) was applied to both surfaces of a 8-inch p-type tantalum substrate in the same manner as described above, prebaked, and heat-treated (calcined) at 600 ° C for 1 hour in a nitrogen atmosphere to prepare a crucible. A sample covered by a passivation film on both sides of the substrate. The carrier life of the sample was measured by a life measuring device (Kobelco Research Institute, RTA-540). The resulting carrier lifetime was 400 μs. For comparison, the same 8-inch p-type 矽 is used by iodine passivation. The substrate was passivated and measured, and the resulting carrier lifetime was 1100 μs.

From the above, it is known that the passivation film obtained by subjecting the passivation material (b2-1) to heat treatment (calcination) exhibits a certain degree of passivation performance and exhibits a negative fixed charge.

[Reference Example 2-4]

Commercially available vanadium oxyacetate (V) (structural formula: VO(OC ₂ H ₅ ) ₃ , molecular weight: 202.13) 1.52 g (0.0075 mol), commercially available aluminum triisopropoxide (structural formula: Al ( OCH(CH ₃ ) ₂ ) ₃ , molecular weight: 204.25) 1.02g (0.005mol), and 10g of novolak resin were dissolved in 10g of diethylene glycol monobutyl ether acetate and 10g of cyclohexane to prepare passivation material (b2) -2).

The passivation material (b2-2) was spin-coated on a 8-inch p-type tantalum substrate (8 Ω.cm to 12 Ω.cm) having a thickness of 725 μm of a natural oxide film removed by using hydrofluoric acid having a concentration of 0.49% by mass in advance. On one side, it was placed on a hot plate and prebaked at 120 ° C for 3 minutes. Thereafter, the film was heated at 650 ° C for 1 hour in a nitrogen atmosphere to obtain a passivation film containing aluminum oxide and vanadium oxide. The film thickness was measured by an ellipsometer and found to be 22 nm. As a result of elemental analysis, it was found that V/Al/C = 71/22/7 (% by mass). The FT-IR of the passivation film was measured, and as a result, a very weak peak derived from an alkyl group was observed in the vicinity of 1200 cm ^-1 .

Then, on the passivation film, a plurality of aluminum electrodes having a diameter of 1 mm were formed by vapor deposition to form a capacitor of a metal-insulator-semiconductor (MIS) structure. The voltage dependence (CV characteristic) of the capacitance of the capacitor was measured by a commercially available prober and an LCR meter (HP company, 4275A). The results show that the flat band voltage (Vfb) is shifted from the ideal value of -0.81V to +0.03V. From the amount of movement, it was found that the passivation film obtained from the passivation material (b2-2) exhibited a fixed charge having a fixed charge density (Nf) of -2.0 × 10 ¹¹ cm ^-2 and a negative value.

In the same manner as described above, the passivation material (b2-2) was applied to both surfaces of a 8 Å p-type ruthenium substrate, prebaked, and heat-treated (calcined) at 600 ° C for 1 hour in a nitrogen atmosphere to prepare ruthenium. A sample covered by a passivation film on both sides of the substrate. The carrier life of the sample was measured by a life measuring device (Kobelco Research Institute, RTA-540). The resulting carrier lifetime was 170 μs. For comparison, the same 8-inch p-type ruthenium substrate was passivated and measured by iodine passivation, and the carrier lifetime was 1100 μs.

From the above, it is known that the passivation film obtained by hardening the passivation material (b2-2) exhibits a certain degree of passivation performance and exhibits a negative fixed charge.

<Case of using cerium oxide as an oxide of a vanadium group element>

[Reference Example 2-5]

A commercially available organometallic thin film coating type material (high purity chemical research institute, SYM-AL04, concentration: 2.3% by mass) which can obtain alumina (Al ₂ O ₃ ) by heat treatment (calcination), A ratio of change in a commercially available organometallic thin film coating type material (high purity chemical research institute, Ta-10-P, concentration: 10% by mass) which can be obtained by heat treatment to obtain cerium oxide (Ta ₂ O ₅ ) While mixing, the passivation material (c2-1) to passivation material (c2-6) shown in Table 7 was prepared.

Rotating coating of passivation material (c2-1)~ passivation material (c2-6) A single-layer p-type tantalum substrate (8 Ω.cm~12 Ω.cm) having a thickness of 725 μm of a natural oxide film was removed by using a hydrofluoric acid having a concentration of 0.49% by mass in advance, and was placed on a hot plate. Prebaking was carried out for 3 minutes at 120 °C. Thereafter, heat treatment (calcination) was performed at 700 ° C for 30 minutes in a nitrogen atmosphere to obtain a passivation film containing aluminum oxide and cerium oxide. The passivation film was used to measure the voltage dependence of the electrostatic capacitance, and the fixed charge density was calculated based on this.

Then, the passivation material (c2-1) to the passivation material (c2-6) were respectively applied to both surfaces of a 8 Å p-type ruthenium substrate, prebaked, and subjected to a nitrogen atmosphere at 650 ° C for 1 hour. Heat treatment (calcination), and a sample covered with a passivation film on both sides of the tantalum substrate was prepared. The carrier life of the sample was measured by a life measuring device (Kobelco Research Institute, RTA-540).

The results obtained are summarized in Table 7. Further, after 14 days from the preparation of the sample, the carrier life was measured again, and as a result, it was found that the carrier life of the passivation film using the passivation material (c2-1) to the passivation material (c2-6) shown in Table 7 was lowered. Within -10%, the decrease in carrier lifetime is small.

Depending on the ratio (mass ratio) of cerium oxide/alumina after heat treatment (calcination), the results are different, but the passivation material (c2-1) to passivation material (c2-6) show negative fixation after heat treatment (calcination). The charge and carrier lifetime also show a certain degree of value, so it is suggested to function as a passivation film.

[Reference Example 2-6]

Commercially available methanol oxime (V) (structure: Ta(OCH ₃ ) ₅ , molecular weight: 336.12) 1.18 g (0.0025 mol) as a compound capable of obtaining cerium oxide (Ta ₂ O ₅ ) by heat treatment (calcination) And commercially available aluminum triisopropoxide as a compound which can be obtained by heat treatment (calcination) to obtain alumina (Al ₂ O ₃ ) (structural formula: Al(OCH(CH ₃ ) ₂ ) ₃ , molecular weight: 204.25 2.04 g (0.010 mol) was dissolved in 60 g of cyclohexane to prepare a passivation material (d2-1) having a concentration of 5 mass%.

The passivation material (d2-1) was spin-coated on a 8-inch p-type tantalum substrate (8 Ω.cm to 12 Ω.cm) having a thickness of 725 μm of a natural oxide film removed by using hydrofluoric acid having a concentration of 0.49% by mass in advance. On one side, it was placed on a hot plate and prebaked at 120 ° C for 3 minutes. Thereafter, the film was heated at 700 ° C for 1 hour in a nitrogen atmosphere to obtain a passivation film containing aluminum oxide and cerium oxide. The film thickness was measured by an ellipsometer and found to be 40 nm. As a result of elemental analysis, it was found that Ta/Al/C = 75/22/3 (wt%). The FT-IR of the passivation film was measured, and as a result, a very weak peak derived from an alkyl group was observed in the vicinity of 1200 cm ^-1 .

Then, on the passivation film, a plurality of aluminum electrodes having a diameter of 1 mm were formed by vapor deposition to form a capacitor of a metal-insulator-semiconductor (MIS) structure. The voltage dependence (CV characteristic) of the capacitance of the capacitor was measured by a commercially available prober and an LCR meter (HP company, 4275A). The results show that the flat band voltage (Vfb) is shifted from the ideal value of -0.81V to -0.30V. From the amount of movement, it was found that the passivation film obtained from the passivation material (d2-1) showed a fixed charge having a fixed charge density (Nf) of -6.2 × 10 ¹⁰ cm ^-2 and a negative value.

In the same manner as described above, the passivation material (d2-1) was applied to both surfaces of a 8 Å p-type ruthenium substrate, prebaked, and heat-treated (calcined) at 600 ° C for 1 hour in a nitrogen atmosphere to prepare ruthenium. A sample covered by a passivation film on both sides of the substrate. The carrier life of the sample was measured by a life measuring device (Kobelco Research Institute, RTA-540). The resulting carrier lifetime was 610 μs. For comparison, the same 8-inch p-type ruthenium substrate was passivated and measured by iodine passivation, and the carrier lifetime was 1100 μs.

From the above, it is known that the passivation film obtained by heat-treating the passivation material (d2-1) exhibits a certain degree of passivation performance and exhibits a negative fixed charge.

[Reference Examples 2-7]

Commercially available methanol oxime (V) (structure: Ta(OCH ₃ ) ₅ , molecular weight: 336.12) 1.18 g (0.005 mol) as a compound capable of obtaining cerium oxide (Ta ₂ O ₅ ) by heat treatment (calcination) a commercially available aluminum triisopropoxide as a compound which can be obtained by heat treatment (calcination) to obtain alumina (Al ₂ O ₃ ) (structural formula: Al(OCH(CH ₃ ) ₂ ) ₃ , molecular weight: 204.25) 1.02 g (0.005 mol) and 10 g of a novolak resin were dissolved in a mixture of 10 g of diethylene glycol monobutyl ether acetate and 10 g of cyclohexane to prepare a passivation material (d2-2).

The passivation material (d2-2) was spin-coated on a 8-inch p-type ruthenium substrate (8 Ω.cm to 12 Ω.cm) having a thickness of 725 μm of a natural oxide film removed by using hydrofluoric acid having a concentration of 0.49% by mass in advance. On one side, prebaking was carried out on a hot plate at 120 ° C for 3 minutes. Thereafter, the film was heated at 650 ° C for 1 hour in a nitrogen atmosphere to obtain a passivation film containing aluminum oxide and cerium oxide. The film thickness was measured by an ellipsometer and found to be 18 nm. As a result of elemental analysis, it was found that Ta/Al/C = 72/20/8 (wt%). The FT-IR of the passivation film was measured, and as a result, a very weak peak derived from an alkyl group was observed in the vicinity of 1200 cm ^-1 .

Then, on the passivation film, a plurality of aluminum electrodes having a diameter of 1 mm were formed by vapor deposition to form a capacitor of a metal-insulator-semiconductor (MIS) structure. The voltage dependence (CV characteristic) of the capacitance of the capacitor was measured by a commercially available prober and an LCR meter (HP company, 4275A). The results show that the flat band voltage (Vfb) is shifted from the ideal value of -0.81V to -0.43V. From the amount of movement, it was found that the passivation film obtained from the passivation material (d-2) showed a fixed charge having a fixed charge density (Nf) of -5.5 × 10 ¹⁰ cm ^-2 and a negative value.

In the same manner as described above, the passivation material (d2-2) was applied to both surfaces of a 8 Å p-type ruthenium substrate, prebaked, and heat-treated (calcined) at 600 ° C for 1 hour in a nitrogen atmosphere to prepare ruthenium. A sample covered by a passivation film on both sides of the substrate. borrow The carrier life of the sample was measured by a life measuring device (Kobelco Research Institute, RTA-540). The resulting carrier lifetime was 250 μs. For comparison, the same 8-inch p-type ruthenium substrate was passivated and measured by iodine passivation, and the carrier lifetime was 1100 μs.

From the above, it is known that the passivation film obtained by subjecting the passivation material (d2-2) to heat treatment (calcination) exhibits a certain degree of passivation performance and exhibits a negative fixed charge.

<Case of using two or more oxides of vanadium elements>

[Reference Example 2-8]

A commercially available organometallic thin film coating type material (high purity chemical research institute, SYM-AL04, concentration: 2.3% by mass) which can obtain alumina (Al ₂ O ₃ ) by heat treatment (calcination), A commercially available organometallic thin film coating type material capable of obtaining vanadium oxide (V ₂ O ₅ ) by heat treatment (calcination) [High Purity Chemical Research Institute, V-02, concentration: 2% by mass], and A commercially available organometallic thin film coating type material obtained by heat treatment (calcination) of lanthanum oxide (Ta ₂ O ₅ ) [High Purity Chemical Research Institute, Ta-10-P, concentration: 10% by mass] The passivation material (e2-1) as a coating type material was prepared by mixing (refer to Table 8).

A commercially available organometallic thin film coating type material (high purity chemical research institute, SYM-AL04, concentration: 2.3% by mass) which can obtain alumina (Al ₂ O ₃ ) by heat treatment (calcination), A commercially available organometallic thin film coating type material capable of obtaining vanadium oxide (V ₂ O ₅ ) by heat treatment (calcination) [High Purity Chemical Research Institute, V-02, concentration: 2% by mass], and A commercially available organometallic thin film coating type material (high purity chemical research institute, Nb-05, concentration: 5% by mass) which can obtain cerium oxide (Nb ₂ O ₅ ) by heat treatment (calcination), A passivation material (e2-2) as a coating type material was prepared (refer to Table 8).

A commercially available organometallic thin film coating type material (high purity chemical research institute, SYM-AL04, concentration: 2.3% by mass) which can obtain alumina (Al ₂ O ₃ ) by heat treatment (calcination), A commercially available organometallic thin film coating type material obtained by heat treatment (calcination) of lanthanum oxide (Ta ₂ O ₅ ) [High Purity Chemical Research Institute, Ta-10-P, concentration: 10% by mass] And a commercially available organometallic thin film coating type material which can obtain cerium oxide (Nb ₂ O ₅ ) by heat treatment (calcination) [High Purity Chemical Research Institute, Nb-05, concentration: 5% by mass] The passivation material (e2-3) as a coating type material was prepared by mixing (refer to Table 8).

A commercially available organometallic thin film coating type material (high purity chemical research institute, SYM-AL04, concentration: 2.3% by mass) which can obtain alumina (Al ₂ O ₃ ) by heat treatment (calcination), A commercially available organometallic thin film coating type material capable of obtaining vanadium oxide (V ₂ O ₅ ) by heat treatment (calcination) [High Purity Chemical Research Institute, V-02, concentration: 2% by mass], A commercially available organometallic thin film coating type material obtained by heat treatment (calcination) of lanthanum oxide (Ta ₂ O ₅ ) [High Purity Chemical Research Institute, Ta-10-P, concentration: 10% by mass], And a commercially available organometallic thin film coating type material (high purity chemical research institute, Nb-05, concentration: 5% by mass) which can obtain cerium oxide (Nb ₂ O ₅ ) by heat treatment (calcination) A passivation material (e2-4) as a coating type material was prepared (refer to Table 8).

Passivation material (e2-1) ~ passivation material (e2-4) and reference In the same manner as in Example 2-1, a single p-type ruthenium substrate (8 Ω.cm to 12 Ω.cm) having a thickness of 725 μm in which the natural oxide film was 725 μm was removed by spin-coating with hydrofluoric acid having a concentration of 0.49% by mass in advance. On the surface, it was placed on a hot plate and prebaked at 120 ° C for 3 minutes. Thereafter, heat treatment (calcination) was performed at 650 ° C for 1 hour in a nitrogen atmosphere to obtain a passivation film containing an oxide of alumina and two or more kinds of vanadium group elements.

The voltage dependence of the electrostatic capacitance was measured using the passivation film obtained above, and the fixed charge density was calculated based on this.

Then, the passivation material (e2-1) to the passivation material (e2-4) were respectively applied to both surfaces of a 8 Å p-type ruthenium substrate, prebaked, and subjected to a nitrogen atmosphere at 650 ° C for 1 hour. Heat treatment (calcination), and a sample covered with a passivation film on both sides of the tantalum substrate was prepared. The carrier life of the sample was measured by a life measuring device (Kobelco Research Institute, RTA-540).

The results obtained are summarized in Table 8.

Depending on the ratio (mass ratio) of oxides of two or more kinds of vanadium elements after heat treatment (calcination), the results are different, but passivation using passivation material (e2-1) to passivation material (e2-4) The film showed a negative fixed charge after heat treatment (calcination), and the carrier lifetime also showed a certain value, so it was suggested to function as a passivation film.

[Reference Example 2-9]

In the same manner as in Reference Example 2-1, a commercially available organometallic thin film coating type material (High Purity Chemical Research Institute, SYM) which can obtain alumina (Al ₂ O ₃ ) by heat treatment (calcination) is used. -AL04, a concentration of 2.3% by mass], a commercially available organometallic thin film coating type material capable of obtaining vanadium oxide (V ₂ O ₅ ) by heat treatment (calcination) [High Purity Chemical Research Institute, V- 02, a concentration of 2% by mass], or a commercially available organometallic thin film coating type material which can obtain cerium oxide (Ta ₂ O ₅ ) by heat treatment (calcination) [High Purity Chemical Research Institute, Ltd., Ta- 10-P, a concentration of 10% by mass] was mixed, and a passivation material (f2-1) to a passivation material (f2-8) as a coating material was prepared (refer to Table 9).

Further, a passivation material (f2-9) using alumina alone was prepared (refer to Table 9).

In the same manner as in Reference Example 2-1, the passivation material (f2-1) to the passivation material (f2-9) were applied to one surface of the p-type germanium substrate, respectively, and then heat-treated (calcined) to prepare a passivation film. The passivation film was used to measure the voltage dependence of the electrostatic capacitance, and the fixed charge density was calculated based on this.

Further, in the same manner as in Reference Example 2-1, the passivation material (f2-1) to the passivation material (f2-9) were respectively applied to both surfaces of the p-type germanium substrate, and heat treatment (calcination) was performed, and the obtained sample was used. To determine the carrier lifetime. The results obtained are summarized in Table 9.

As shown in Table 9, when the alumina/vanadium oxide or yttrium oxide in the passivation material is 90/10 and 80/20, the deviation of the value of the fixed charge density is large, and the negative fixed charge density cannot be stably obtained. However, it was confirmed that a negative fixed charge density can be achieved by using alumina and cerium oxide. It has been found that when a passivation material using alumina, vanadium oxide or yttrium oxide of 90/10 and 80/20 is measured by the CV method, it may become a passivation film which exhibits a positive fixed charge, and thus is not stably Showing a negative fixed charge. Further, a passivation film exhibiting a positive fixed charge can be used as a passivation film of an n-type germanium substrate. On the other hand, the passivation material (f2-9) in which the alumina reaches 100% by mass cannot obtain a negative fixed charge density.

[Reference Example 2-10]

A single crystal germanium substrate using boron as a dopant was used as the germanium substrate 101, and a solar cell element having the structure shown in Fig. 7 was produced. After the surface of the ruthenium substrate 101 is subjected to a texture treatment, only the coating-type phosphorus diffusion material is applied to the light-receiving surface side, and the diffusion layer 102 (phosphorus diffusion layer) is formed by heat treatment. Thereafter, the coated phosphorus diffusion material was removed using dilute hydrofluoric acid.

Then, on the light-receiving side, a SiN film is formed as a light-receiving surface anti-reflection film 103 by plasma CVD. Thereafter, the passivation material (a2-1) prepared in Reference Example 2-1 was applied to a region other than the contact region (opening portion OA) on the back side of the tantalum substrate 101 by an inkjet method. Thereafter, heat treatment is performed to form a passivation film 107 having an opening OA. Further, as the passivation film 107, a sample using the passivation material (c2-1) prepared in Reference Example 2-5 was separately prepared.

Then, on the light-receiving surface anti-reflection film 103 (SiN film) formed on the light-receiving surface side of the ruthenium substrate 101, a paste containing silver as a main component is screen-printed in the shape of a predetermined finger electrode and a bus bar electrode. On the back side, a paste with aluminum as a main component was screen printed onto the entire surface. Thereafter, heat treatment (burn-through) is performed at 850 ° C to form an electrode (first electrode 105 and second electrode 106), and aluminum is diffused into a portion of the opening OA of the back surface to form a BSF layer 104, and FIG. 7 is formed. The solar cell element of the structure shown.

Further, in the formation of the silver electrode on the light-receiving surface, a burn-through step in which the SiN film is not formed is described. However, the opening portion OA may be formed in advance in the SiN film by etching or the like, and then the silver electrode may be formed. .

For comparison, in the above-described fabrication step, the formation of the passivation film 107 is performed, and the aluminum paste is printed on the entire surface on the back side, and the p ⁺ layer 114 and the second electrode corresponding to the BSF layer 104 are formed on the entire surface. The corresponding electrode 116 forms the solar cell element of the structure of Fig. 4. The solar cell elements were evaluated for characteristics (short circuit current, open circuit voltage, curve factor, and conversion efficiency). The evaluation of the characteristics was carried out in accordance with JIS-C-8913 (2005) and JIS-C-8914 (2005). The results are shown in Table 10.

As shown in Table 10, the solar cell element having the passivation film 107 has an increase in short-circuit current and open-circuit voltage as compared with the solar cell element having no passivation film 107, and the conversion efficiency (photoelectric conversion efficiency) is increased by 0.6% at the maximum.

Japanese Patent Application No. 2012-160336, Japanese Patent Application No. 2012-218389, Japanese Patent Application No. 2013-011934, Japanese Patent Application No. 2013-040153, and Japanese Patent Application No. 2013-103571 All disclosures are incorporated herein by reference. All the documents, Japanese patent application, and technical standards described in the present specification are incorporated herein by reference in the same manner as the following. The literature, Japanese patent applications, and technical standards are incorporated by reference.

1‧‧‧p-type semiconductor substrate

2‧‧‧n ⁺ type diffusion layer

3‧‧‧Anti-reflective film

4‧‧‧p ⁺ diffusion layer

5‧‧‧Back electrode

6‧‧‧ Passivation layer

7‧‧‧Lighted surface electrode

Claims (10)

A composition for forming a passivation layer, comprising at least one selected from the group consisting of a fatty acid decylamine, a polyolefin diol compound, and an organic filler, and a compound represented by the following formula (I), M(OR ¹ ) _m (I) [wherein M contains at least one metal element selected from the group consisting of Nb, Ta, V, Y, and Hf; and R ¹ independently represents an alkyl group or a carbon number of 1 to 8 carbon atoms; An aryl group of 6 to 14; m represents an integer of 1 to 5]. The composition for forming a passivation layer according to claim 1, further comprising a compound represented by the following formula (II). Wherein R ² each independently represents an alkyl group having 1 to 8 carbon atoms; n represents an integer of 0 to 3; and X ² and X ³ each independently represent an oxygen atom or a methylene group; and R ³ , R ⁴ and R; ⁵ independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. The composition for forming a passivation layer according to the first or second aspect of the invention, comprising the polyolefin diol compound, wherein the polyolefin diol compound comprises a compound selected from the group consisting of the following formula (III) At least one of them, In the formula (III), R ⁶ and R ⁷ each independently represent a hydrogen atom or an alkyl group, R ⁸ represents an alkylene group; n is an integer of 3 or more; and a plurality of R ⁸ may be the same or different. . The composition for forming a passivation layer according to any one of claims 1 to 3, wherein the fatty acid decylamine contains a compound selected from the group consisting of the following formula (1) At least one of the group consisting of the compound represented by the formula (2), the compound represented by the formula (3), and the compound represented by the formula (4), R ⁹ CONH ₂ . . . . (1) R ⁹ CONH-R ¹⁰ -NHCOR ⁹ . . . . (2) R ⁹ NHCO-R ¹⁰ -CONHR ⁹ . . . . (3) R ⁹ CONH-R ¹⁰ -N(R ¹¹ ) ₂ . . . . (4) In the general formula (1), the general formula (2), the general formula (3), and the general formula (4), R ⁹ and R ¹¹ each independently represent an alkyl group having 1 to 30 carbon atoms or a carbon number of 2 An alkenyl group of ~30, R ¹⁰ represents an alkylene group having 1 to 10 carbon atoms; and a plurality of R ^{11 's} may be the same or different. The composition for forming a passivation layer according to any one of claims 1 to 4, wherein the organic filler is contained, and the organic filler is selected from the group consisting of acrylic resins, cellulose resins, and polystyrene resins. At least one of the group consisting of. A semiconductor substrate with a passivation layer, comprising: a semiconductor substrate; and a passivation layer disposed on the entire surface or a portion of the semiconductor substrate, and as described in any one of claims 1 to 5 A heat treatment material for a composition for forming a passivation layer. A method of manufacturing a semiconductor substrate with a passivation layer, comprising: applying a composition for forming a passivation layer according to any one of items 1 to 5 of the patent application to the entire surface or a part of the semiconductor substrate, and a step of forming a composition layer; and a step of heat-treating the composition layer to form a passivation layer. A solar cell element comprising: a semiconductor substrate, wherein a p-type layer and an n-type layer are pn-bonded; and a passivation layer disposed on the entire surface or a portion of the semiconductor substrate, and is in the first to the first The passivation layer forming group according to any one of the items 5 The heat-treated product of the object; and the electrode are disposed on one or more layers selected from the group consisting of the p-type layer and the n-type layer. A method for producing a solar cell element, comprising: pn bonding having a p-type layer and an n-type layer joined together, and one or more selected from the group consisting of the p-type layer and the n-type layer The one or both surfaces of the surface of the semiconductor substrate having the electrode having the electrode on the layer having the electrode, the passivation layer forming composition according to any one of the first to fifth aspects of the present invention is formed. a step of constituting the layer; and a step of heat-treating the composition layer to form a passivation layer. A solar cell comprising: the solar cell element according to claim 8; and a wiring material provided on the electrode of the solar cell element.