JP2000353666A - Semiconductor thin film and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a crystalline silicon film at a low temperature by forming an atomic layer and a layer, having a peak concentration of a catalyst element around an interface between a substrate and a semiconductor thin film, and subsequently made to contain the catalyst element in and outside the semiconductor thin film. SOLUTION: On a glass substrate 1, a coating 2 made of a material such as silicon oxide is formed through sputtering method, and then a semiconductor thin film 3 such as a crystalline silicon film is formed thereon. Subsequently, around an interface 4 between the substrate 1 and the semiconductor thin film 3, an atomic layer is formed, which contains a catalyst element for accelerating the growth of a crystal. Furthermore, a layer having a peak concentration of the catalyst element is formed around the interface 4 between the substrate 1 and the semiconductor thin film 3, and the catalyst element is contained in and outside the semiconductor thin film 3. Therefore, it is possible to manufacture a semiconductor thin-film device, such as a low-temperature forming thin- film transistor having high performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor thin film device in the semiconductor industry and a method for manufacturing the same.
The present invention relates to a technique for forming a high-performance semiconductor thin film at a low temperature on a surface of a substrate that melts at a low temperature.

In particular, it is formed on the surface of a glass substrate or the like.
The present invention relates to a thin film transistor (TFT) used for an active matrix type liquid crystal display and the like and a method for manufacturing the same.

[0003]

2. Description of the Related Art In an active matrix type liquid crystal display, transistors used include:
There is a pixel transistor for switching each pixel, and a high mobility control transistor of a peripheral circuit that sends a control signal based on image information to be displayed to each pixel transistor. Conventionally, among these, a pixel transistor has a TF using hydrogenated amorphous silicon (a-Si: H) as an active layer.
T was used, and as its manufacturing method, a plasma-enhanced chemical vapor deposition (PCVD) was applied. This a-S
Since the i: H TFT can be manufactured at a substrate temperature of about 300 ° C., there is an advantage that an inexpensive translucent glass substrate can be used. However, the mobility of the n-type TFT is 1 cm ² / V
For a p-type TFT having a small s and a p-type TFT, practical mobility cannot be obtained, and the transistor cannot be used as a control transistor. Therefore, a transistor manufactured as an IC chip is mounted on a substrate.

On the other hand, polycrystalline silicon (poly-Si)
Has an advantage that it has a high mobility for both n-type and p-type and can be applied to a control transistor. However, poly-Si usually requires a high-temperature step of 600 ° C. or more, such as film formation by a reduced pressure CVD method.
There is a problem that an inexpensive glass substrate cannot be applied.

In recent years, low-temperature poly-Si (low-temperature po
The research and development of the ly-Si) technology is being actively carried out, and its practical application is being promoted. One is to irradiate the a-Si: H film in a pulsed manner with an excimer laser beam having a wavelength in the ultraviolet region where absorption in the a-Si: H film is extremely large.
This is a method for producing a polycrystalline film by recrystallization by rapid heating, melting and cooling (Patent: 2725669, etc.).
This method can form a TFT having a high mobility at a low temperature of 600 ° C. or lower, but it is difficult to form a TFT over a large area with high productivity because a laser is used. Further, generally, the a-Si: H film contains 10 atom% or more of hydrogen, and as it is, poly is considered to be caused by bumping of hydrogen due to rapid heating of excimer laser light.
-Since the peeling of the Si thin film and the roughening of the surface occur, there has been a problem that a heat treatment step for desorbing hydrogen in the film must be added in advance. In order to solve these issues,
The following techniques have been proposed for producing a low-temperature poly-Si film.

As a method of forming a crystalline silicon film without performing a dehydrogenation treatment required for an a-Si: H film by a PCVD method, first, an amorphous silicon film is formed by a sputtering method, Japanese Patent Application Laid-Open No. 5-182908 discloses a method of crystallization by irradiating an energy beam such as a laser and growing a crystalline silicon film thereon by sputtering.

High frequency inductively coupled plasma (ICP: Induct)
Production of a crystalline silicon film by a chemical vapor deposition process using a source gas decomposed by plasma decomposition using ive coupled plasma is disclosed in
65212 and JP-A-11-74204. In this method, for example, an electrode (antenna) for generating an ICP (document: Hideaki Kanai: Applied Physics, Vol. 63, No. 6, 1994, pp. 5)
59 to 567), high-frequency power is applied to generate high-density plasma of the source gas, and the source gas is decomposed and highly excited to form a film. JP-A-10-26521
In Japanese Patent Publication No. 2, a high-frequency power of 800 W or more can provide a polycrystalline silicon thin film having an electric conductivity higher by one digit or more. It is shown that a crystalline silicon thin film cannot be obtained.

In the deposition of a silicon thin film on a substrate, the substrate is irradiated with ions of any of hydrogen, a rare gas, and a gas containing silicon, and the momentum of these ions is added to the deposited silicon atoms while adding the momentum. Japanese Patent Application Laid-Open No. 10-60647 discloses a method of manufacturing a crystalline silicon film by raising the substrate temperature.

A catalyst that promotes crystal growth during deposition is Si
Heating above the melting temperature of, a part of the molecules of the raw material gas is brought into contact with the heated catalyst to decompose it and perform film formation by CVD and crystal growth on the substrate. It is described in JP-A-8-250438. In this method, some of the flying species become hot, and the substrate surface behaves as if it were hot, and polycrystalline silicon is generated at a low substrate temperature. Actually, the raw material gas is a mixed gas of a silicon (Si) compound gas and another substance, and the catalyst is heated by the supplied electric power. Then, the power supplied to the catalyst is set such that the catalyst body temperature is higher than the silicon melting temperature, the power supply conditions for the catalyst, the pressure conditions for lowering the pressure of the reaction chamber for forming the silicon thin film, and By increasing the mixing ratio of the source gas to increase the ratio of the gas of the substance to the gas of the silicon compound so that the silicon thin film generated by the deposited species becomes a polycrystalline thin film, A polycrystalline silicon thin film is formed on a substrate.

A method for producing a crystalline silicon film at a temperature that a glass substrate can withstand by adding such a catalytic element to amorphous silicon and performing a heat treatment or the like is disclosed in
-267989. As the catalyst, Ni, Fe, Co, Pt (JP-A-6-244103)
Publication), Pd, Cu, Au, In, Sn, P, A
s, Sb, Group VIII element, Group IIIb element, Element IVb, Group Vb element (JP-A-7-135174), Ru, Rh, P
d, Os, Ir, Ag (JP-A-8-69967)
It is shown. In addition, as a method of addition, formation of a film containing a catalyst element (JP-A-6-244103), spin coating (JP-A-7-135174), and inclusion in a wiring material (JP-A-9-260670). Publication), a catalytic element is provided on the surface of amorphous silicon,
It shows a method of adding to the film by a subsequent heat treatment or the like.

[0011]

When the above method is adopted, it is considered possible to manufacture a crystalline silicon film at a temperature at which a glass substrate can be applied. There were challenges.

In the catalytic CVD method (JP-A-8-250438), a film is formed only by active species (radicals) generated by thermal decomposition in a gas phase. As described in the specification, in order to form a crystalline silicon film without increasing the substrate temperature, not only decomposition but also contact with a thermal catalyst, the temperature of some radicals (kinetic energy) Is trying to raise enough. In order to obtain such an effect, there is a problem that electric power must be supplied so that the temperature of the thermal catalyst becomes extremely high, 1700 to 1800 ° C.

This problem becomes more pronounced when a silicon film is formed on a large-area substrate such as a liquid crystal display. Further, there is a problem that it is necessary to prevent a rise in the temperature of the structure of the apparatus or an inexpensive glass substrate with respect to radiant heat from such a high-temperature thermal catalyst.

A method of growing a crystal by adding a catalytic element for promoting crystal growth to amorphous silicon (Japanese Patent Laid-Open No. 7-26)
No. 7989), various elements exhibiting a catalytic effect are disclosed. As a particularly effective example, when Ni is used, crystallization of a silicon film is started at a temperature of 580 ° C. to 450 ° C. Is disclosed in Japanese Patent Laid-Open No. 6-244103.
Japanese Patent Application Laid-Open No. Hei 7-135174 discloses that the temperature of about 550 ° C. is optimal from the viewpoint of productivity and the like. However, as described in JP-A-7-135174 and the like, it is preferable that the amount of the catalyst element present in the active layer is small, and further, in order to promote crystallization, strong light such as an excimer laser is used. There is a problem that the number of manufacturing steps is further increased as compared with a conventional crystallization technique using an excimer laser such as irradiation. For example, as a treatment for reducing the abundance of the catalytic element in the active layer, the catalytic element is selectively introduced (Patent 2
No. 793858), 550 ° C., 10 in a hydrogen chloride atmosphere.
The catalyst element is removed by a treatment for about 60 minutes.
No. 0-135476) are disclosed, but all of them have an increase in the number of manufacturing steps, and there are problems in that the materials to be used and the structure of the TFT are restricted, and the productivity is reduced.

In PCVD, a method of heating a raw material gas through a thermal catalyst in advance and supplying it to a plasma generator (Japanese Patent Laid-Open No. 10-310867) is different from the catalytic CVD method in that the gas is decomposed and excited. From the place,
Since there is a distance to a region contributing to film formation, such as plasma or the substrate surface and its vicinity, there is a problem that gas molecules decomposed and excited cannot be used effectively. Therefore, usable gases and film-forming targets are limited, and only examples of formation of a protective film such as diamond-like carbon or an insulating film of carbide, nitride, or oxide are disclosed.

In the method of forming a crystalline silicon film by PCVD using ICP (Japanese Patent Laid-Open Nos. 10-265212 and 11-74204), high-density plasma of a source gas is generated by high-frequency inductive coupling. Thus, decomposition and excitation of the source gas are performed more actively than in the conventional parallel plate high-frequency PCVD to form a crystalline silicon film. However, the film obtained was confirmed by Raman spectroscopy to be microcrystals (Japanese Patent Laid-Open No. 10-26).
No. 5212), and those which have been confirmed in terms of electric characteristics have a problem that sufficient crystallinity and film quality are not obtained, such as high photoconductivity (Japanese Patent Application Laid-Open No. 11-74204). These problems are all technologies that focus on high decomposition and high excitation of the source gas, and are caused by the lack of means for promoting crystallization and reducing the hydrogen concentration in the film. It is considered something.

A method of forming a crystalline silicon film by colliding silicon-containing molecules with accelerated ions in the gas phase to impart momentum to the silicon-containing molecules is described in US Pat. As the ion to be irradiated, an ion having a large collision cross-sectional area and heavier than a silicon molecule is preferable, and thus Xe ion is used as described in JP-A-10-60647. This Xe is expensive and does not collide with molecules containing silicon in the gas phase,
When irradiating a film during film formation without losing kinetic energy or momentum, there is a problem in that defects or Xe are mixed in the film, thereby deteriorating the film quality.

An amorphous silicon film is formed by a sputtering method, and is crystallized by irradiating an energy ray such as a laser.
The method of growing a crystalline silicon film thereon by sputtering has a low hydrogen content, but the silicon film formation process must be performed in two stages, and furthermore, during this process, irradiation with laser or the like is performed. In this case, there is a problem that the process is complicated and productivity is low.

The present invention solves the above-mentioned problems of the prior art, and provides a manufacturing method and apparatus for forming a crystalline silicon film of higher quality at a low temperature, and a TFT having excellent characteristics and reliability. The purpose is to provide.

[0020]

In order to achieve the above object, a semiconductor thin film device according to the present invention comprises a semiconductor thin film device having a semiconductor thin film formed on a substrate surface. Forming an atomic layer containing a catalytic element that promotes the formation of a layer having a peak of the concentration of the catalytic element in the vicinity of the interface, and including the catalytic element in a crystalline semiconductor thin film and outside the thin film. It is characterized by the following. Further, according to the method for manufacturing a semiconductor thin film device of the present invention, a high quality semiconductor thin film device having good crystallinity can be manufactured without increasing the substrate temperature.

In the semiconductor thin film device or the method of manufacturing the same according to the present invention, the temperature of the substrate is set at 100 ° C. to 600 ° C. during film formation.
By setting the temperature to ° C, an inexpensive substrate such as glass can be used, which is preferable. Use of a light-transmitting substrate as the substrate is preferable in manufacturing a product that transmits light, such as a transmissive liquid crystal display.

In the structure of the present invention or the method of the present invention, at least one kind of an insulating layer and a conductive layer is formed on a part or the entire surface of a substrate, and a crystalline semiconductor thin film is formed on the insulating film or the conductive film. Is formed, when manufacturing a semiconductor device on a substrate such as inexpensive glass,
It is preferable because the influence of impurities from a substrate such as glass can be reduced, and the structure of the semiconductor device can be variously designed according to the purpose, such as a bottom gate type TFT.

In a preferred embodiment of the present invention, wherein the semiconductor thin film is a microcrystalline silicon thin film, a
This is preferable because the field-effect mobility of the TFT can be higher than that of the -Si: H film. According to a preferred configuration in which the semiconductor thin film is a polycrystalline silicon thin film, TF
The field effect mobility of T can be made higher. Further, the thickness of the semiconductor thin film is 5 nm or more and 200 n
The value of m or less is preferable because it can be applied to a TFT with the same film thickness without additional etching or film formation.

The inventors of the present invention have proposed a method for producing a crystalline semiconductor thin film on a substrate surface at a temperature at which an amorphous substrate does not melt using a catalytic element. The present inventors have newly found that it is effective to form a catalyst element layer on the surface by vapor deposition or the like, and have reached the present invention. Furthermore, when the catalyst element layer formed on the substrate surface is formed by sputter deposition, the subsequent semiconductor thin film, gate insulating film, and even the gate electrode can be manufactured by sputter deposition, while maintaining the vacuum atmosphere of the manufacturing apparatus. The present invention has been accomplished by newly finding that it is possible to provide a high-quality semiconductor thin film substrate.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically with reference to examples.

FIG. 1 is a schematic view of a first embodiment of a semiconductor thin film device according to the present invention. First, a film 2 made of silicon oxide or the like is formed on a substrate 1 made of glass or the like by a sputtering method.
It is formed with a film thickness of 0 to 300 nm (FIG. 2A). The method for forming the coating film 2 may be other means such as a plasma CVD method, a normal pressure CVD method, a vapor deposition method, and a low pressure CVD method. Ni, Fe, Co, Pt, P
d, Cu, Au, In, Sn, P, As, Sb, Group VIII element, IIIb element, IVb element, Vb element, Ru, Rh,
A catalyst element layer 9 of a thin film of Pd, Os, Ir, Ag, or a thin film containing these is formed by a sputter deposition method (FIG. 2B). In addition, a method such as spin coating can be used for forming the catalyst element layer 9.

Thereafter, a semiconductor thin film 3 such as a crystalline silicon film is formed to a thickness of 10 to 50 nm (FIG. 2).
(C)). Heat treatment is performed to distribute the catalytic element in the semiconductor thin film 3 and the coating 2. This heat treatment may be performed before, during, or after the formation of the semiconductor thin film. The thickness of the semiconductor thin film 3 is not limited to this range, but is set in the range of 5 to 200 nm in accordance with the structure of the TFT and the consistency with other processes. If the semiconductor thin film 3 is silicon, heat treatment at 450 to 600 ° C. or irradiation with an excimer laser may be performed as necessary. FIG. 2D shows the distribution of the concentration of the catalytic element in the substrate, the film, or the semiconductor thin film after the formation of the semiconductor thin film: 3. Further, FIG. 3 shows the distribution of the concentration of the catalytic element in the stacked structure from the surface to the depth direction. As can be seen from this figure, in the thin film semiconductor substrate formed by the manufacturing process of the present invention, the distribution of the concentration of the catalytic element has a peak inside the thin film semiconductor substrate. Of course, there may be other portions having a concentration value larger than the absolute value of the catalyst element concentration at this peak, but at least one portion may have a layer having a concentration relatively higher than the concentration in the vicinity. It is a feature.

Next, an insulating layer such as a silicon oxide film: 7
Is formed with a thickness of 50 to 300 nm. The insulating layer 7 is formed by sputtering, normal pressure CVD, or plasma CVD.
Other means such as a method, a vapor deposition method, and a low pressure CVD method may be used. Next, a metal film made of Ti, Mo, W, Al, Ta, or the like is formed to a thickness of 50 to 300 nm by a sputter deposition method, and the metal film is etched by using a photoresist patterned by photolithography as a mask.
A gate electrode 8 is formed. The gate electrode material is not limited to a metal film, but may be a silicon film.

Using the gate electrode 8 as a mask, ions containing impurities are implanted to form an impurity doping layer having a source: 5 / drain: 6 region. This doping layer is formed, for example, in the case of forming an n-type layer by hydrogen dilution 5%.
This is performed by ion doping using PH ₃ as an ion source gas. The conditions for applying ion doping are as follows: acceleration voltage: 5 to 100 kV, total ion implantation amount: 10 ¹⁴ to 10 ¹⁶
cm ^-2 . For these conditions, optimal conditions and gas concentrations are appropriately selected according to the thickness of the mask, the thickness of the doping layer to be formed, and the like. The formation of the p-type layer is performed by ion doping using hydrogen diluted 5% B ₂ H ₆ or the like as an ion source gas. In addition, in the ion doping method, impurities serving as a dopant and hydrogen are implanted at the same time, so that implantation defects are compensated by hydrogen and activation / crystallization is promoted, so that a low-resistance doping layer is formed at a low temperature. You. In this embodiment, the ion implantation is performed by removing the insulating layer in the region to be implanted. However, the ion implantation may be performed by leaving the insulating layer on the surface of the region to be implanted. In that case, the acceleration voltage of the ions is preferably 10 kV or more, depending on the conditions such as the film thickness.

Next, a silicon oxide film serving as an interlayer insulating film is formed to a thickness of 100 to 500 nm by a sputtering method, a normal pressure CVD method, a plasma CVD method, or the like, so as to make electrode contact with the source / drain regions. Next, an interlayer insulating film is opened by photolithographic etching to form source / drain electrodes, thereby manufacturing a thin film transistor.

As an embodiment of the present invention, a glass substrate was mounted on a deposition sample table of a sputter deposition apparatus, and first, an amorphous silicon oxide film was formed as a substrate film by a sputter deposition method. Subsequently, a catalyst element layer was formed by sputter deposition in the same vacuum vessel using a target on which the catalyst element material was mounted. A comparison was made between the case where the substrate was not heated during vapor deposition and the case where the temperature was controlled to 600 ° C. or less by heating. It was empirically found that there was an optimum heating condition depending on the semiconductor thin film formation temperature in the subsequent process. . On the surface of the catalyst element layer thus formed, a crystalline silicon thin film was further deposited by sputtering while heating the substrate to 600 ° C. or lower. Further, on the surface of the crystalline silicon, an amorphous silicon oxide thin film was sputter-deposited in the same vacuum vessel as a gate insulating layer.

The crystallinity of the crystalline silicon thin film formed as described above can be determined by X-ray diffraction, electron beam diffraction, Raman spectroscopy, transmission electron microscope observation, ultraviolet reflection, visible / ultraviolet light absorption, etc. Is defined by one or more. Further, the hydrogen content of the film is determined by a secondary ion mass spectrometry, an infrared absorption method, or the like.

According to the method for manufacturing a semiconductor thin film according to the present invention, a semiconductor thin film device such as a bottom gate TFT thin film transistor can be similarly manufactured with high performance and under low temperature conditions. FIG. 4 is a schematic view showing a manufacturing process of a bottom gate type thin film transistor as a second embodiment in the semiconductor thin film device according to the present invention.

First, a silicon oxide film having a thickness of 100 to 500 nm is formed as an insulating film 2 on a substrate 1 made of glass or the like by sputtering deposition, normal pressure CVD or the like (FIG. 4A). A metal film made of Ti, Mo, W, Al, Ta, or the like is formed to a thickness of 100 to 500 nm, and the metal film is etched using a photoresist patterned by photolithography as a mask to form a gate electrode 8. (FIG. 4 (b)).

Next, a silicon oxide film as a gate insulating layer 7 was formed by sputtering evaporation, atmospheric pressure CVD, etc.
It is formed with a thickness of 300 nm (FIG. 4C). Note that the silicon oxide film is formed by a sputtering method or a plasma CV method.
Other means such as a D method, a thermal evaporation method, and a low pressure CVD method may be used.
A catalytic element layer is formed on the surface of the insulating layer by the same vapor deposition method. (FIG. 4 (d)) As the catalyst element, the same element as that shown in the embodiment is selected.

Next, a crystalline silicon film having a thickness of 10 to 50 nm is formed as the semiconductor thin film 3 (FIG. 4).
(E)). The film thickness is not limited to this range,
5 to 20 depending on the structure of the TFT and compatibility with other processes, etc.
Set in the range of 0 nm. Note that heat treatment at 450 to 600 ° C., irradiation with excimer laser, and the like are performed as necessary to improve the crystallinity of the crystalline silicon film.

Next, using the photoresist patterned by photolithography as a mask, ions containing impurities are implanted into the crystalline silicon thin film to form impurity doped layers serving as source / drain regions. This doping layer is formed by, for example, hydrogen dilution 5% in the formation of an n-type layer.
This is performed by ion doping using PH ₃ as an ion source gas.
The conditions for applying ion doping are the accelerating voltage:
5 to 100 kV, total ion implantation amount: 10 ¹⁴ to 10 ¹⁶ cm
^-2 . For these conditions, optimal conditions and gas concentrations are appropriately selected depending on the thickness of the mask, the thickness of the doping layer to be formed, and the like. The p-type layer is formed by ion doping using hydrogen diluted 5% B ₂ H ₆ or the like as an ion source gas. In addition, in the ion doping method, impurities serving as a dopant and hydrogen are implanted at the same time, so that implantation defects are compensated by hydrogen and activation / crystallization is promoted, so that a low-resistance doping layer is formed at a low temperature. You.
Although a photoresist is used as a mask for ion doping in this embodiment, a silicon oxide film or a silicon nitride film may be formed on a silicon thin film, and these films and the photoresist may be used as a mask.

Next, a silicon oxide film serving as an interlayer insulating film: 11 is formed by sputtering, plasma CVD, or normal pressure CVD.
In order to make an electrode contact with the source: 5 / drain: 6 region, the interlayer insulating film is opened by photolithographic etching to form an electrode, and an electrode is formed. To complete.

By adopting the above method,
A semiconductor thin film with excellent crystallinity can be formed in a temperature range in which a glass substrate can be used. Therefore, even when a thin film transistor is manufactured over a large-area glass substrate such as an active matrix liquid crystal display, a thin film transistor having excellent characteristics and reliability can be manufactured.

Further, when the substrate is heated during the film formation, the effect of low-temperature crystallization by the catalytic element is promoted, and a semiconductor thin film having more excellent crystallinity can be formed. can do. When a glass substrate is used as the substrate as in this embodiment, the heating temperature is preferably 100 to 600 ° C.
Further, the temperature is more preferably 300 to 500 ° C. from the viewpoint of minimizing the distortion of the glass and improving the characteristics of the oxide film.

[0041]

As described above, according to the configuration of the present invention, a semiconductor thin film device such as a high performance low temperature formed thin film transistor can be manufactured. Therefore, even when a thin film transistor is manufactured on a glass substrate having a large area such as an active matrix liquid crystal display, a thin film transistor having excellent characteristics and reliability can be manufactured with high productivity.

In the structure of the present invention or the method of the present invention, if a crystalline silicon semiconductor thin film is formed by a sputter deposition method using a silicon target material as a raw material, an interlayer insulating layer, a substrate coating, an insulating layer, and a catalyst can be formed. The element layer, and further the formation of the gate electrode can be performed by the same sputter deposition process, simplifying the manufacturing process,
It is possible to manufacture a silicon TFT required for a liquid crystal display or the like. Further, in the method of forming a semiconductor thin film of the present invention, a film forming rate and crystallinity can be more controlled by utilizing a hydrogen gas or an inert gas during thin film deposition.

Further, in the structure of the present invention or the method of the present invention, by setting the temperature of the substrate at 100 ° C. to 600 ° C. at the time of film formation, an inexpensive substrate such as glass can be used. In the structure of the present invention or the method of the present invention, by using a light-transmitting substrate as the substrate, a product that transmits light, such as a transmissive liquid crystal display, can be manufactured. Further, in the structure of the present invention, the hydrogen contained in the obtained semiconductor thin film is set to 10 atom% or less, thereby improving the characteristics and reliability of the semiconductor film and the semiconductor device to be formed, and further improving the properties of laser recrystallization and the like. When high quality is required, dehydrogenation is not required.

In the structure of the present invention or the method of the present invention, at least one kind of an insulating film and a conductive film is formed on a part or the whole surface of the substrate, and a crystalline film is formed on the insulating film or the conductive film. By forming a semiconductor thin film, when manufacturing a semiconductor device on an inexpensive substrate such as glass, it is possible to reduce the influence of impurities from the substrate such as glass and the like. Can be designed in various ways according to the purpose. Further, in the configuration of the present invention, according to the preferred configuration in which the semiconductor thin film is a microcrystalline silicon thin film, the field effect mobility of the TFT can be increased as compared with the a-Si: H film, and When high quality such as recrystallization is required, dehydrogenation treatment becomes unnecessary. Further, in the configuration of the present invention, according to the preferred configuration in which the semiconductor thin film is a polycrystalline silicon thin film, the field effect mobility of the TFT can be further increased.

In the structure of the present invention or the method of the present invention, when the thickness of the semiconductor thin film is 5 nm or more and 200 nm or less, there is an effect that the semiconductor thin film can be directly used as an active layer of a TFT.

[Brief description of the drawings]

FIG. 1 is a schematic view of an embodiment of a semiconductor thin film device according to the present invention.

FIG. 2 is an example of a semiconductor thin film device according to the present invention, TF.
Schematic diagram of some steps in the method of manufacturing T

FIG. 3 is a schematic diagram of a catalyst element concentration distribution in a depth direction of a semiconductor thin film device according to the present invention.

FIG. 4 is a partial schematic process diagram of a method of manufacturing a bottom gate thin film transistor according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Coating 3 Semiconductor thin film 4 Semiconductor thin film / substrate interface 5 Source 6 Drain 7 Insulating layer 8 Gate electrode 9 Catalytic element layer 10 Catalytic element distribution 11 Interlayer insulating film

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mikihiko Nishitani 1006 Kazuma Kadoma, Osaka Pref.Matsushita Electric Industrial Co., Ltd. 72) Inventor Michihiko Takase 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Munehiro Shibuya 1006 Odaka Kadoma, Kadoma City Osaka Pref. 1006 Kazuma Kadoma Matsushita Electric Industrial Co., Ltd.F-term (reference) BB01 CC02 CC08 DD02 DD13 DD17 DD24 EE03 EE04 EE44 FF02 FF28 GG02 GG13 GG14 GG25 GG32 GG33 GG43 GG 53 HJ01 HJ04 HJ13 NN02 NN23 NN34 NN35 PP01 PP03 PP34 QQ11

Claims (9)

[Claims] An atomic layer containing a catalytic element for promoting crystal growth is formed near an interface between a substrate and a semiconductor thin film, and a layer having a peak concentration of the catalytic element is formed in the atomic layer. A method for producing a semiconductor thin film, wherein the catalyst element is contained in or outside the semiconductor thin film. 2. An atomic layer containing a catalytic element for promoting crystal growth near an interface between a substrate and a semiconductor thin film, and a layer having a peak concentration of the catalytic element in the atomic layer.
A semiconductor thin film comprising the catalyst element contained in or outside the semiconductor thin film. 3. A semiconductor thin film formed on a substrate contains hydrogen having a content of 10 atom% or less, and at least Ni, Fe, Co, Pt, Pd, Cu, A as a catalytic element.
u, In, Sn, P, As, Sb, Ru, Rh, Pd,
The semiconductor thin film according to claim 2, wherein the semiconductor thin film is microcrystalline silicon or polycrystalline silicon containing one of Os, Ir, and Ag, and the crystalline semiconductor thin film is used as an active layer. 4. A light-transmitting substrate is used as a substrate, and at least one or more films of an insulating film and a conductor film are formed on a part or the entire surface of the substrate, and a crystalline semiconductor thin film is formed on the film. The semiconductor thin film according to claim 2, wherein is formed. 5. A semiconductor thin film having a thickness of 5 nm or more and 200
3. The semiconductor thin film according to claim 2, wherein the thickness is not more than nm. 6. A step of forming a catalyst element for promoting crystal growth or an atomic layer containing the element on a substrate surface arranged in a vacuum apparatus, and after the step, a raw material containing constituent elements of a semiconductor thin film And forming a thin film by irradiating the substrate with a discharge under reduced pressure to form a thin film.
The method according to claim 1, wherein a crystalline semiconductor thin film is formed on the substrate controlled as follows. 7. In a vacuum apparatus comprising a vacuum vessel connected to a gas inlet and a vacuum exhaust port, the catalyst element for promoting crystal growth on the surface of the substrate disposed in the vacuum vessel, or the catalyst element. Forming an atomic layer containing, and discharging and decomposing the raw material containing the constituent elements of the semiconductor thin film under reduced pressure to generate a plasma having an electron density of 10 ¹⁰ to 10 ¹³ / cm ^-3. 7. The method of manufacturing a semiconductor thin film according to claim 6, wherein the step of irradiating the substrate with ions and radicals to form a thin film is successively performed in the same vacuum apparatus. 8. Placing the substrate on a substrate mounting table in a vacuum vessel, generating a plasma containing the catalyst element for promoting crystal growth, or a raw material containing the element, and forming the plasma on the substrate mounting table. By applying a voltage in between,
The method according to claim 6, wherein the catalytic element is injected into a substrate to form an atomic layer containing the element. 9. The method according to claim 9, wherein the substrate is placed on a substrate mounting table in a vacuum vessel, and the catalyst element for promoting crystal growth or a raw material containing the element is thin-film deposited on the surface of the substrate by a sputter deposition method. The method for producing a semiconductor thin film according to claim 6, wherein an atomic layer containing a catalytic element is formed.