JP5418242B2 - Vapor deposition material and method for forming vapor deposition film using the vapor deposition material - Google Patents

Description

The present invention relates to a method of forming a deposited film had use a vapor deposition material and the vapor deposition material used in forming the deposited film by a reactive plasma vapor deposition method. More specifically, than the conventional can forming a deposited film at low energy, and it relates to method of forming a deposited film had use a vapor deposition material and the vapor deposition material can impart directivity to sublimated evaporation material .

  Up to now, transparent and conductive ITO (tin-doped indium oxide) has been used as a transparent conductive material for transparent electrodes such as LCD (Liquid Crystal Display), organic EL, plasma display panels, and thin film solar cells. The formed transparent conductive film has been generally used. While ITO has the advantages of excellent transparency and low resistance, indium is very expensive, so if a transparent conductive film formed of ITO is used, the solar cell is inevitably expensive. There was a problem of becoming. The problem of indium resource depletion has also been pointed out. Furthermore, the ITO film has a problem in durability, and it has been pointed out that there is a problem that resistance is increased by heat treatment, or it is altered by a reducing agent or an acidic chemical during etching. In view of the above, in recent years, ZnO has attracted attention as a transparent conductive material replacing ITO, and a ZnO film formed thereby has been widely used in the field of solar cells and the like.

  On the other hand, in such a method for forming a transparent conductive film, a physical vapor deposition method is used in which a film forming material is vaporized by some method in a vacuumed container and deposited on a substrate placed nearby to form a thin film. (Hereinafter referred to as PVD method) is used. The PVD method includes a vacuum deposition method, a molecular beam deposition method, an ion plating method, an electron beam deposition method, a sputtering method, and the like. Among them, the reactive property is obtained because a film can be formed without heating the substrate. Plasma vapor deposition (hereinafter referred to as RPD method) has attracted attention.

  In the physical vapor deposition method that employs the principle of sublimating the film forming material including the RPD method and depositing it on the substrate, the sublimated film forming material does not deposit well at the target location of the deposition target, There is a problem that the film thickness and composition of the deposited film are uneven, or the sublimated film forming material is detached from the deposition object and adheres to the inside of the apparatus, thereby contaminating the inside of the apparatus or wasting the material. Has occurred. In order to solve such a problem, a control plate in which a vapor passage hole is formed so that the vapor discharge flow rate per unit area is maximized at the position of the substrate end rather than the center portion, and the passage hole is provided. An evaporation source is disclosed in which a partition plate that imparts directivity to the flow of steam that has passed through is disposed (see, for example, Patent Document 1). In the present invention, the film thickness distribution in the width direction of the substrate is controlled by appropriately controlling the flow rate distribution of the sublimated vapor deposition material in the longitudinal direction of the nozzle opening, and directivity is applied to the flow of the vapor deposition material in the nozzle opening. By providing, the utilization efficiency of the vapor deposition material is improved.

  In addition, in a device for manufacturing a thin film by continuously attaching vapor generated from an evaporation source onto a film-like substrate, a shielding plate for regulating the incident angle of the vapor incident on the film-like substrate was provided. Is disclosed (for example, refer to Patent Document 2). The crucible body has an opening for discharging film forming material vapor, and a cylindrical portion that surrounds the opening and protrudes from the crucible body and serves as a film forming material vapor discharge port. A crucible for vacuum deposition having a shape in which a side surface is inclined in at least one direction so as to spread toward a discharge direction of a film material and capable of appropriately adjusting the directivity of the evaporation flow according to the configuration of the vacuum deposition apparatus, etc. is disclosed. (For example, refer to Patent Document 3). Further, in an electron beam vapor deposition apparatus that evaporates a deposition material by irradiating an electron beam by irradiating an electron beam, a shield for controlling the evaporation direction of the deposition material is disposed immediately above the evaporation source, and the evaporation material is evaporated. An electron beam vapor deposition apparatus that improves the directivity of a vapor deposition material that is evaporated by controlling the direction is disclosed (for example, see Patent Document 4).

JP 2008-121098 (Claim 1, paragraph [0013], paragraph [0014]) JP-A-6-228743 (Claim 3) JP 2007-297695 A (Claim 1, paragraph [0012]) JP-A-10-259474 (Claim 7, paragraph [0016])

  However, in the inventions disclosed in the above-mentioned conventional patent documents 1 to 4, directivity is imparted to the sublimated film forming material by providing a partition plate, a shield, and the like as a part of the apparatus. For this reason, problems such as adhesion of vapor deposition materials inside the apparatus and waste of materials still occur and have not yet been solved. In addition, when providing directivity to the sublimated film forming material by providing a shield or the like in the apparatus or the like in this way, a considerable amount of vapor deposition material adheres to the partition plate or shield and frequently performs a cleaning process. There is a need. Furthermore, when changing the material composition, etc., it is necessary to replace the partition plate, shield, etc. each time.

  In the plasma-type vapor deposition method, it is necessary to irradiate the vapor deposition material with high-energy plasma in order to start sublimation until the vapor deposition material starts sublimation. If the sublimation of the vapor deposition material is started once, this becomes the starting point and the sublimation is activated and chain sublimation occurs. Therefore, after the sublimation is started, the film can be formed with lower energy than in the initial stage. However, in the initial stage where sublimation of the vapor deposition material begins, it is necessary to irradiate the vapor deposition material with high-energy plasma. As described above, in the initial stage, the deposition material is cracked due to the irradiation of the deposition material with high-energy plasma. In addition, when the current value of plasma discharge increases, a part of the vapor deposition material collides with the base material before being ionized, which causes the base material to be damaged or the conductivity of the vapor deposition film to be formed. There is also a problem of worsening.

An object of the present invention is to realize film formation with lower energy than before and improve the apparatus when forming a vapor deposition film by a plasma type vapor deposition method, particularly in an initial stage where sublimation of a vapor deposition material starts. and to provide a method for forming a deposited film had use sublimated evaporation material and the vapor deposition material can impart directivity to deposition material without.

A first aspect of the present invention is a vapor deposition material for forming a vapor deposition film by a reactive plasma vapor deposition method using a metal oxide powder containing ZnO powder. A base portion 10a on which one or more protrusions 11 are formed, and at least as many through holes 12 as the protrusions 11 are provided at positions corresponding to the protrusions 11, and the through holes 12 accommodate all the protrusions 11 on the upper surface of the base portion 10a. The protrusion 11 has a maximum height h from the surface of the base 10a of 1 to 10 mm, a maximum width w of the portion protruding from the surface of the base 10a is 1 to 10 mm, and the mask 10b. The through-hole 12 provided in is characterized in that the height H is 1.2 to 3 times the maximum height h of the protrusion 11 and the width W is 1 to 4 times the maximum width w of the protrusion 11. To do.

  The second aspect of the present invention is an invention based on the first aspect, and the protrusion 11 is a sintered body formed in a conical or hemispherical shape using a material having the same composition as the material used for forming the base portion 10a. It is characterized by comprising a pulverized product obtained by pulverizing a sintered body obtained by firing a sintered body or a material having the same composition.

  The third aspect of the present invention is the invention based on the first aspect, wherein the protrusion 11 is formed by subjecting the surface of the base portion 10a to mechanical grinding or chemical erosion. .

  A fourth aspect of the present invention is an invention based on the first to third aspects, and is characterized in that the mask 10b is formed of a material having the same composition as the material used for forming the base portion 10a.

  A fifth aspect of the present invention is an invention based on the first to third aspects, and is characterized in that the mask 10b is made of a material having a lower conductivity than the base 10a.

Sixth aspect of the present invention is a method for forming a deposited film had use the evaporation material based on the first to fifth aspect.

  The vapor deposition material of the first aspect of the present invention includes a base having one or more protrusions formed on the upper surface and a mask having at least the same number of through holes as the protrusions. The through hole is provided at a position corresponding to the protrusion of the base, and a mask is installed on the upper surface of the base so that the through hole accommodates all the protrusions. The protrusion has a maximum height h from the base surface of 1 to 10 mm, and a maximum width w of the portion protruding from the base surface is 1 to 10 mm. The through hole provided in the mask has a height H that is 1.2 to 3 times the maximum height h of the protrusion, and a width W that is 1 to 4 times the maximum width w of the protrusion. Thereby, in the initial stage where the sublimation of the vapor deposition material starts, film formation with lower energy than before can be performed, and directivity can be imparted to the sublimated vapor deposition material without improving the apparatus.

Forming method of the sixth aspect deposited film of the present invention, using the evaporation material of the present invention, because can deposited at lower energy than conventional, less damage, a deposited film capable of expressing a high conductivity formed I can .

It is a perspective view which shows the vapor deposition material of this invention. It is the perspective view which showed the base and mask which comprise the vapor deposition material of this invention separately, respectively. It is the sectional view on the AA line of FIG. It is a perspective view which shows an example of the mask which comprises the vapor deposition material of this invention. It is a figure which shows the relationship between a plasma discharge current and discharge time. It is a schematic sectional drawing which shows the principal part of a RPD apparatus.

  Next, an embodiment for carrying out the present invention will be described with reference to the drawings.

The present invention is a vapor deposition material and method for forming a deposited film had use the vapor deposition material can be suitably used for forming a deposited film by RPD method. In general, the RPD method is a method in which a plasma beam generator is installed in a normal vapor deposition apparatus to cause arc discharge, and the sublimated particles passing through the arc plasma are ionized and accelerated to be deposited on the cathode. High-speed film formation is possible as compared with the vapor deposition method. The kinetic energy of the flying particles in the ordinary vapor deposition method is about 0.1 eV and that in the sputtering method is about 100 eV, whereas that in the RPD method is several tens of eV, which is between the vapor deposition method and the sputtering method. Therefore, the RPD method can form a thin film with better adhesion to the substrate than the ordinary vapor deposition method, and can form a film with higher density and lower defects than the sputtering method, raising the substrate temperature. A film with good crystallinity can be obtained without this.

As shown in FIG. 6, an apparatus 60 used for the RPD method includes a vacuum chamber 61 and a plasma beam generator 62 provided on the side wall of the chamber 61. The chamber 61 is made of a conductive member and is grounded. A hearth 64 on which the vapor deposition material 10 is placed and a plasma beam controller 66 for guiding the plasma beam to the hearth 64 side are provided at the bottom of the chamber 61. The plasma beam controller 66 has an annular shape concentric with the hearth 64 and surrounds the hearth 64, and a magnet 66a and a coil 66b are disposed therein to form a magnetic field. A base material holder 68 that holds the base material 67 and is disposed so as to face the hearth 64 is provided in the upper portion of the chamber 61. The base material holder 68 is made of a conductive member and is grounded via a bias control means (not shown). The base material holder 68 may be configured to be able to transport a plurality of base materials into the chamber. A gas inlet 61a and a gas outlet 61b for introducing and discharging argon gas and the like are provided on the side wall of the chamber 61, respectively. The plasma beam generator 62 is a pressure gradient type, and a magnet 62a and a coil 62b for converging the generated plasma beam are arranged, and LaB ₆ and Ta are used as the thermionic emission elements. A beam guide steering coil 62c for guiding the plasma beam into the chamber 61 is installed around the plasma beam generator 62. Two or more plasma beam generators 62 may be used. For example, when three plasma beam generators are used, two can be used for co-evaporation and the remaining one can be used for plasma assist.

  The vapor deposition material of the present invention used for forming a vapor deposition film by such an RPD method includes a base 10a and a mask 10b as shown in FIG. 1 or FIG. One or more protrusions 11 are formed on the upper surface of the base 10a. By forming the protrusions 11, when forming a vapor deposition film by the RPD method, it is possible to realize film formation with lower energy than in the past, particularly in the initial stage where the vapor deposition material 10 starts sublimation. The plasma deposition principle utilizes the fact that electrons such as argon gas that are in a plasma state in a chamber concentrate and move to a highly conductive substance or region. That is, the sublimation of the vapor deposition material starts when electrons in plasma collide with the surface of the vapor deposition material, but in the conventional vapor deposition material, the surface of the vapor deposition material is flat, so that the plasma hits the surface of the vapor deposition material. However, since the heat diffuses into the vapor deposition material, very high energy is required in the initial stage where sublimation begins.

  For example, as shown in FIG. 5, first, in order to promote sublimation of the vapor deposition material, it is necessary to increase the plasma discharge current to an A value with a constant gradient α in the initial stage. At this time, when a conventional vapor deposition material is used, the A value needs to be about 60 amperes. For this reason, the vapor deposition material is cracked by high energy or rapid heating, or the base material and the film are damaged. On the other hand, since the vapor deposition material of the present invention has a predetermined size and a predetermined number of protrusions, plasma-intensive irradiation occurs on the protrusions of the vapor deposition material. For this reason, compared with the case where the conventional vapor deposition material is used, it can be made low energy in an initial stage. That is, if the vapor deposition material of the present invention is used, the A value can be suppressed to 40 amperes or less.

  The protrusion 11 has a maximum height h from the surface of the base 10a of 1 to 10 mm, preferably 1 to 5 mm, and a maximum width w of the portion protruding from the surface of the base 10a of the protrusion 11 is 1 to 10 mm, preferably 1 to 5 mm. It is in the range. The reason why the maximum height h is set in the above range is that if it is less than 1 mm, the effect of promoting the sublimation of the vapor deposition material cannot be sufficiently obtained, while if it exceeds 10 mm, cracks may occur in the protruding portion. Moreover, the reason why the maximum width w is in the above range is that if the thickness is less than 1 mm, the vapor deposition material cannot be supported, and if it exceeds 10 mm, the effect of promoting the sublimation of the vapor deposition material cannot be obtained sufficiently. is there.

  The protrusion 11 is preferably formed using a material having the same composition as the material used to form the base portion 10a, and a sintered body formed in a conical or hemispherical shape or a material having the same composition is fired. It is preferable to consist of a pulverized product obtained by pulverizing the obtained sintered body. The reason why it is preferable to use a material having the same composition as the material used to form the base 10a is to prevent impurities from entering the film. The protrusion 11 may be formed by subjecting the surface of the base portion 10a to a mechanical grinding process or a chemical erosion process.

  At least the same number of through holes 12 as the protrusions 11 are formed in the mask 10b installed on the upper surface of the base portion 10a where the protrusions 11 are formed. The through hole 11 is provided at a position corresponding to the protrusion 11 included in the base portion 10a, and is installed on the upper surface of the base portion 10a so that all the protrusions 11 are accommodated in the through hole 12. As a result, as shown in FIG. 3, the protrusion 11 provided on the base portion 10 a is surrounded by the side wall of the through hole 12.

  The sublimation of the vapor deposition material starts from the protrusion 11 as described above. When sublimation of the vapor deposition material starts from the protrusion 11, the sublimated vapor deposition material passes through the through-hole 12 formed in the mask 10 b and reaches the deposition target. For this reason, when passing through the through hole 12, directivity can be imparted to the vapor deposition material that rises radially by the side wall of the through hole 12. The number of the through-holes 12 should just be provided at least by the same number as the protrusion 11, and may be provided more than the number of the protrusions 11. FIG. The aperture ratio of the mask 10b, that is, the ratio of the total volume of the through holes to the total volume of the mask including the volume of the through holes is preferably 20 to 90%. If it is less than the lower limit value, the evaporation amount per unit area time (deposition amount on the substrate) is remarkably lowered, and the deposition amount on the mask is liable to increase. On the other hand, if the upper limit is exceeded, the mask is likely to break due to insufficient mask strength.

  The size of the through hole 12 is a size that can accommodate the protrusion 11. That is, the height H is 1.2 to 3 times the maximum height h of the protrusion 11, and the width W is 1 to 4 times the maximum width w of the protrusion 11. If the height H of the through-hole 12 is less than the lower limit, the effect of imparting directivity to the sublimated vapor deposition material will not be sufficient. On the other hand, when the upper limit value is exceeded, it becomes difficult for the plasma to reach the vapor deposition material, resulting in a problem that the vapor deposition rate decreases. Further, if the width W of the through hole 12 is less than the lower limit value, the protrusion 11 cannot be accommodated. On the other hand, if the width W exceeds the upper limit value, the effect of imparting directivity to the sublimated vapor deposition material becomes insufficient. Among these, the height H of the through hole 12 is 1.3 to 1.5 times the maximum height h of the protrusion 11, and the width W is 1.2 to 1.7 times the maximum width w of the protrusion 11. Preferably there is.

  The mask 10b is preferably formed of a material having the same composition as the material used to form the base portion 10a. Even if a part of the mask 10b sublimates and adheres to the deposited film, it is inferior in that the directivity decreases due to partial evaporation from the mask surface by being formed of the same composition material. Therefore, the composition of the film is not affected. The mask 10b can also be formed of a material having a lower conductivity than the base portion 10a. By being formed of a material having low conductivity, plasma irradiation can be avoided, and as a result, an effect of maintaining high directivity can be obtained.

  The through hole 12 has a cylindrical shape as shown in FIG. 1 or 2, that is, a circular shape from the upper surface, a honeycomb shape from the upper surface, or an upper surface as shown in FIG. 4. It is preferable that the shape from is a lattice shape. The circular shape is particularly effective for suppressing variations in film thickness on the film formation surface. In addition, the honeycomb shape is effective for increasing the aperture ratio without impairing the strength of the mask. Moreover, if it is a grid | lattice form, in manufacture of a mask, formation of the through-hole by dry etching using a blast process etc. will become easy.

  Next, a method for producing the vapor deposition material of the present invention will be described. The vapor deposition material 10 is formed by installing the mask 10b for imparting directivity to the sublimated vapor deposition material on the upper surface of the base 10a on which the projections 11 for promoting sublimation are formed on the surface. The Although the manufacture of the base 10a and the manufacture of the mask 10b can be performed independently, any of them may be performed first. Here, the manufacturing procedure of the base 10a will be described first.

  The base 10a is not particularly limited as long as the protrusion 11 for promoting sublimation is formed on the surface thereof, and can be manufactured using the same material as a conventionally known vapor deposition material. As a conventional vapor deposition material, for example, a ZnO vapor deposition material made of ZnO pellets made of ZnO powder having a ZnO purity of 98% or more and used for forming a transparent conductive film containing an element such as Ga is used. As an example. Taking this ZnO vapor deposition material as an example, the manufacturing procedure of the base 10a will be described in detail below.

First, the ZnO powder and Ga ₂ O ₃ powder was prepared as a metal oxide powder, the metal oxide powder, and a binder, by mixing the organic solvent, the concentration is preferably 30 to 75 wt%, more preferably A slurry of 40 to 65% by mass is prepared (first step). The concentration of the slurry is limited to 30 to 75% by mass. If the slurry exceeds 75% by mass, the slurry is non-aqueous, so that stable mixed granulation is difficult. This is because it is difficult to obtain a ZnO sintered body. The ZnO powder is preferably a high-purity ZnO powder having a purity of 98% or more, and more preferably 98.4% or more. This is because if the purity of the ZnO powder is 98% or more, a decrease in conductivity due to the influence of impurities can be suppressed. The average particle size of the ZnO powder is preferably in the range of 0.1 to 5.0 μm. If it is less than 0.1 μm, the powder is too fine and agglomerates, so that the handling of the powder tends to be poor, and it tends to be difficult to prepare a high-concentration slurry. This is because it tends to be difficult to obtain.

The Ga ₂ O ₃ powder is added so that a Ga element contained in the deposited material after production is contained at a predetermined ratio. When adding Ga ₂ O ₃ powder, the concentration of the Ga element is preferably added mixed to be in the range of 0.1 to 15 wt% when a polycrystalline ZnO deposition material. It is preferable to use a Ga ₂ O ₃ powder having an average particle size in the range of 0.01 to 1 μm. This is because the use of a powder in the range of 0.01 to 1 μm is suitable for uniformly dispersing the Ga ₂ O ₃ powder. In this embodiment, Ga ₂ O ₃ powder is added as a metal oxide powder other than ZnO powder. However, other than Ga ₂ O ₃ powder, Y ₂ O ₃ powder, La ₂ O ₃ powder, Sc ₂ O ₃ powder are used. CeO ₂ or Ce ₂ O ₃ powder, Pr ₆ O ₁₂ powder, Nd ₂ O ₃ powder, Pm ₂ O ₃ powder, Sm ₂ O ₃ powder and the like. When adding CeO ₂ powder, it is preferable to add cerium oxide particles having a primary particle size of nanoscale in consideration of prevention of uneven distribution of Ce abundance, reactivity with ZnO matrix and purity of Ce compound. . In the present specification, the average particle diameter means that, according to the laser diffraction / scattering method (microtrack method), Nikkiso Co., Ltd. (FRA type) is used, and sodium hexametaphosphate is used as a dispersion medium. Is an average of values measured three times for 30 seconds.

  It is preferable to use polyethylene glycol or polyvinyl butyral as the binder, and ethanol or propanol as the organic solvent. The binder is preferably added in an amount of 0.2 to 5.0% by mass.

The wet mixing of the metal oxide powder, the binder, and the organic solvent, particularly the wet mixing of the metal oxide powder and the organic solvent that is the dispersion medium is performed by a wet ball mill or a stirring mill. In the wet ball mill, when ZrO ₂ balls are used, wet mixing is performed for 8 to 24 hours, preferably 20 to 24 hours, using a large number of ZrO ₂ balls having a diameter of 5 to 10 mm. The reason why the diameter of the ZrO ₂ balls is limited to 5 to 10 mm is that mixing is insufficient when the diameter is less than 5 mm, and there is a problem that impurities increase when the diameter exceeds 10 mm. The reason why the mixing time is as long as 24 hours is that the generation of impurities is small even if the mixing is continued for a long time.

  Next, the slurry is spray-dried to obtain a mixed granulated powder having an average particle size of preferably 50 to 250 μm, more preferably 50 to 200 μm (second step). The spray drying is preferably performed using a spray dryer.

Next, this granulated powder is put into a mold and pressure-molded to obtain a cylindrical shaped body (third step). As the mold, a uniaxial press apparatus or a cold isostatic pressing apparatus (CIP (Cold Isostatic Press) forming apparatus) is used. In uniaxial pressing apparatus, granulated powder 750~2000kg / cm ² (73.6~196.1MPa), preferably uniaxial pressing at a pressure of 1000~1500kg / cm ² (98.1~147.1MPa) In the CIP molding apparatus, the granulated powder is CIP molded at a pressure of 1000 to 3000 kg / cm ² (98.1 to 294.2 MPa), preferably 1500 to 2000 kg / cm ² (147.1 to 196.1 MPa). The reason why the pressure is limited to the above range is to increase the density of the molded body, prevent deformation after sintering, and eliminate the need for post-processing.

  In the third step, except for the fourth embodiment described later, a number of recesses corresponding to the number of protrusions formed in the fifth step described later are formed on the surface of the molded body. The recesses fix the projections 11 to the surface of the base 10a, and can be formed by fixing the projections 11 to the recesses using, for example, a binder used when producing the granulated powder.

  After obtaining the molded body, the molded body is usually fired at a predetermined temperature to obtain a sintered body (fourth step). Following the third step, the following first to fourth embodiments are performed. Through one of the steps shown, one or more protrusions 11 are formed on the surface of the base 10a (fifth step).

  In 1st Embodiment, after forming a recessed part in the surface of a molded object first in the said 3rd process, the elongate rod-shaped molded object of the same composition as the said molded object is formed by extrusion molding. Then, this elongated rod-shaped molded product is cut into a predetermined length so that the maximum height h of the protrusion 11 formed by firing, which will be described later, falls within the above range, thereby obtaining a thin rod body. The extrusion molding is not particularly limited, and a general extrusion molding machine can be used. The lower part of the obtained thin rod is inserted into a recess formed on the surface of the molded body in the third step to provide a protrusion on the surface of the molded body. Specifically, it is preferable to use a method in which the protrusions are fixed to the recesses using the binder used when producing the granulated powder as an adhesive.

  And the protrusion provided in the surface of the molded object is baked. Firing of the protrusions in the fifth step is performed simultaneously in the fourth step of firing the molded body to obtain a sintered body. Sintering is carried out at a temperature of 1000 ° C. or higher, preferably 1200 to 1400 ° C. for 1 to 10 hours, preferably 2 to 5 hours in the atmosphere, inert gas, vacuum or reducing gas atmosphere. Thereby, the pellet which has desired ZnO as a main component is obtained. The relative density of the pellets is preferably 90% or more, and more preferably 95% or more. This is because if the relative density is 90% or more, splash during film formation can be reduced.

  The size of the pellet excluding the protrusions 11 is preferably 5 to 50 mm in diameter and 2 to 30 mm in thickness. The diameter of the pellet is set to 5 to 50 mm for the purpose of stable and high-speed film formation. If the diameter is less than 5 mm, there is a problem that splash or the like occurs. If the diameter exceeds 50 mm, the hearth (deposition material reservoir) There is a defect that causes non-uniformity of the film in vapor deposition and a decrease in the film formation rate due to a decrease in filling rate. Further, the thickness is set to 2 to 30 mm for the purpose of stable and high-speed film formation. If the thickness is less than 2 mm, there is a problem that splash or the like occurs. There is a defect that causes non-uniformity of the film in vapor deposition and a decrease in the film formation rate due to a decrease in the filling rate into the reservoir. The ZnO pellets may be polycrystalline or single crystal. As described above, the base 10a having the desired protrusion 11 formed on the surface can be obtained.

In 2nd Embodiment, after forming a recessed part in the surface of a molded object in the said 3rd process, mixed granulated powder of the same composition as the powder used for formation of the molded object in the said 3rd process is made into the opening of the said recessed part. A conical or hemispherical body is obtained by packing into a conical or hemispherical female mold having a radius corresponding to the part. At this time, it is preferable to pressurize at a pressure of 1000 to 3000 kg / cm ² (98.1 to 294.2 MPa), thereby increasing the density of the protrusions 11 and preventing deformation after sintering, thereby making post-processing unnecessary. .

  The cone or sphere thus obtained is taken out from the mold, and the base of the cone or sphere is inserted into the recess formed on the surface of the molded body in the third step to be placed on the surface of the molded body. Protruding objects are provided. Specifically, it is preferable to use a method in which the protrusions are fixed to the recesses using the binder used when producing the granulated powder as an adhesive.

  And the protrusion provided in the surface of the molded object is baked. The projecting of the protrusions in the fifth step is performed at the same time as the first embodiment, in the fourth step of firing the molded body to obtain a sintered body, and under the same conditions as in the first embodiment. it can. The preferred size of the pellet excluding the protrusions 11 is the same as that in the first embodiment.

  In 3rd Embodiment, after forming a recessed part in the surface of a molded object in the said 3rd process, the sintered compact of the same composition as the sintered compact obtained by baking the molded object obtained at the said 3rd process is grind | pulverized. Thus, a pulverized product that is smaller than the opening of the recess and larger than the depth of the recess is obtained. The sintered body used to obtain the pulverized product can be obtained by firing a molded body formed with the same material and under the same conditions as the molded body obtained in the third step under the same conditions as those in the fourth step. Sintered body. The sintered body is preferably pulverized with a stone mill, an airflow pulverizer or an impact pulverizer.

  The base portion of the pulverized product thus obtained is inserted into the concave portion 10a formed on the surface of the molded body in the third step to provide a projecting material on the surface of the molded body. Specifically, it is preferable to carry out by a method using an instantaneous adhesive.

  And in a 4th process, the molded object by which the protrusion was provided in the surface is baked. The firing here can be performed under the same conditions as in the first embodiment. Since the protrusions in this embodiment are fired once and have already become sintered bodies, the main objects are sintering of the formed body and joining between the protrusions and the formed body. The preferred size of the pellet excluding the protrusions 11 is the same as that in the first embodiment.

  In the fourth embodiment, unlike the first to third embodiments described above, in this third step, it is not necessary to provide a recess on the surface of the molded body, but in consideration of the surface treatment in the subsequent step, the third step It is necessary to form the formed body thicker than the formed body in the first to third embodiments.

  In this embodiment, the molded body is fired at a predetermined temperature subsequent to the third step to obtain a sintered body (fourth step), as in the normal manufacturing process of the vapor deposition material. Subsequent to the fourth step, the surface of the sintered body is subjected to a mechanical grinding process or a chemical erosion process to form protrusions 11 on the surface of the base 10a (fifth process). For the mechanical grinding process, lathe / milling, laser processing, or hydraulic processing can be suitably used. In addition, acid-alkali treatment can be suitably used for the chemical erosion treatment.

  Then, the manufacturing procedure of the mask 10b installed in the upper surface of the base 10a is demonstrated. When the mask 10b is formed of a material having the same composition as the material used for forming the base portion 10a, it is not necessary to go through the fifth step of forming the protrusions 11 and the through hole 12 is formed. The base 10a can be manufactured by almost the same method as the manufacturing procedure. That is, after obtaining the molded body through the first to third steps in the manufacturing procedure of the base portion 10a, the molded body is fired under the same conditions as in the fourth step in the manufacturing procedure of the base portion 10a. obtain. At this time, the size of the pellet is preferably 5 to 50 mm, the diameter of which is the same as the diameter of the base portion 10a. On the other hand, since the thickness corresponds to the height of the through-hole 12 formed in the subsequent process, the thickness is 1.2 to 3 times, preferably 1.3 to 1.5 times the maximum height h of the protrusion 11.

  When the mask 10b is formed of a material having a lower conductivity than the material used for forming the base portion 10a, it is the same as the above method except that the composition of the material is changed in the first step in the manufacturing procedure of the base portion 10a. Then, a molded body is obtained. And this molded object can be baked on the same conditions as the 4th process in the manufacture procedure of the said base 10a, and a sintered compact can be obtained.

  A method of providing the through holes 12 in the sintered body thus obtained is a method of performing mechanical grinding treatment or chemical erosion treatment. For example, the following first to third methods may be mentioned. The first method is a mechanical grinding method using a diamond electrodeposition tool (drill). Specifically, drilling is performed using this drill. Thereby, the cylindrical through-hole 12 as shown in FIG. 1 or FIG. 2, ie, the shape from the upper surface, can be provided.

  The second method is a processing method using a laser. Specifically, for example, cutting is performed using a YAG laser. Thereby, the through-hole 12 having a honeycomb shape from the upper surface can be provided (not shown). The third method is a dry etching method using blasting. Specifically, a mask having a shape to be processed is fixed, and fine abrasive grains are sprayed onto the surface together with high-pressure air or gas. Thereby, as shown in FIG. 4, the through-hole 12 whose shape from the upper surface is a grid | lattice form can be provided. By providing the desired through hole 12 in the sintered body by the first to third methods, the mask 10b constituting the vapor deposition material 10 of the present invention can be obtained. In the first to third methods, the position where the protrusion 11 is formed in the base 10a is stored in advance, and the position where the through hole 12 is opened is determined based on this data.

  The mask 10b obtained by the above method is placed on the upper surface of the base 10a. At this time, the mask 10b is installed on the upper surface of the base portion 10a so that all the protrusions 11 are accommodated in the through holes 12.

  Next, a film forming process for forming a vapor deposition film by the RPD method using the vapor deposition material manufactured according to the present invention and the RPD apparatus will be described.

First, in the RPD device 60 shown in FIG. 6, the vapor deposition material 10 manufactured according to the present invention is loaded into the hearth 64, and the base material 67 is mounted on the base material holder 68. Examples of the substrate 67 include a glass substrate, a semiconductor wafer, and a resin film. Next, the chamber 61 is evacuated by a turbo molecular pump (not shown). Then, Ar gas is supplied into the chamber 11 from the gas supply port 61a, and the total pressure in the chamber 61 is controlled to 5 × 10 ^{−3 to} 3 × 10 ⁻² Pa. Moreover, you may mix oxygen gas as needed. Further, the bias control means is operated, and a predetermined bias voltage is applied to the base material holder 68 to keep the base material holder 68 at a negative potential with respect to the chamber 61. Next, arc discharge is performed from the plasma beam generator 62, a magnetic field is generated by the plasma beam controller 66, and the arc plasma is guided to the deposition material 10 side loaded in the hearth 64.

  Then, when performing arc discharge from the plasma beam generator 62, as shown in FIG. 5, sublimation of the vapor deposition material 10 is started by increasing the plasma discharge current to the A value with a constant gradient α. As described above, the reason why the plasma discharge current is increased at a constant gradient α until the sublimation of the vapor deposition material 10 starts is because it is necessary to input high energy for promoting sublimation in the initial stage. A value can be made into the range of 30-40 amperes by using this vapor deposition material. This is because if the vapor deposition material of the present invention is used, plasma is intensively irradiated on the protrusions of the vapor deposition material, so that sublimation can be started with lower energy than in the prior art. As a result, it is possible to prevent cracking of the vapor deposition material due to high energy input or rapid heating, and to eliminate the fluctuation of the film formation rate caused by the cracking of the vapor deposition material and the occurrence of splash generated from the crack end face. it can. In addition, damage to the substrate and the film can be reduced.

  Subsequently, it is lowered to a B value that is a current value lower than the A value, and the deposition film is continuously formed on the base material 67. The reason why stable film formation is performed even if the current value is reduced to the B value is that once evaporation or sublimation is performed from the surface of the vapor deposition material, the surface becomes active, and evaporation or sublimation is possible even with a small current. It is. The B value is selected within a range of 10 to 80 amperes, which is a current value lower than the A value. The reason why the B value is within the above range is that evaporation or sublimation stops when it is less than the lower limit value, and film formation does not occur, and if the upper limit value is exceeded, stable film formation cannot be maintained. This is because problems such as difficulty in control occur.

  The vapor deposition material 10 is exposed to the arc plasma and sublimates, and at the same time, is ionized in the plasma. The ionized vapor deposition material is accelerated by the electric field due to the bias voltage, travels toward the base material 67, and deposits on the surface of the base material 67 with high energy.

  As described above, by using the vapor deposition material of the present invention, it is possible to realize film formation with lower energy than in the prior art, particularly in the initial stage where sublimation of the vapor deposition material starts. As a result, energy can be reduced in the film forming process, and cracking of the vapor deposition material due to high energy input or rapid heating can be prevented. Splash that occurs from the end face can be eliminated. In addition, damage to the substrate and the film can be reduced.

  Furthermore, since directivity can be imparted to the vapor deposition material that has been sublimated without improving the apparatus, problems such as unevenness in film thickness and composition can be solved. Further, contamination inside the apparatus due to the sublimated vapor deposition material can be prevented, or the material can be effectively used.

  Moreover, the vapor deposition film formed using the vapor deposition material of the present invention is formed with a lower energy than before, has little damage, and can exhibit high conductivity.

  Next, examples of the present invention will be described in detail together with comparative examples.

<Example 1>
First, a high purity ZnO powder having a purity of 99.7%, a high purity Ga ₂ O ₃ powder having a purity of 99.5%, a binder, and an organic solvent were prepared. These were mixed to prepare a slurry having a concentration of 30% by mass. At this time, ZnO powder having an average particle diameter of 2 μm, Ga ₂ O ₃ powder having an average particle diameter of 1.5 μm, ethanol as an organic solvent, and polyvinyl butyral as a binder were used. The amount of binder added was 0.5% by mass. Also, Ga ₂ O ₃ powder, Ga element contained in the deposited material after formation, were added to contain 5 wt%. A slurry having a concentration of 30% by mass was prepared by wet mixing with a ball mill.

  Next, the prepared slurry was spray-dried using a spray dryer to obtain a mixed granulated powder having an average particle size of 200 μm, and the granulated powder was put into a predetermined mold and press-molded by a uniaxial press machine. And the recessed part was formed in the surface of the obtained molded object with the press.

  Next, a part of the obtained mixed granulated powder is packed in a conical female mold having a radius corresponding to the opening of the recess formed on the surface of the molded body, and pressurized at a pressure of 50 MPa. did. The resulting cone was removed from the mold, and the base of this cone was inserted and bonded into the recess using the binder used when producing the granulated powder as an adhesive to provide a protrusion on the surface of the molded body. .

  Next, the molded body provided with the protrusions is sintered in the atmosphere at a temperature of 1300 ° C. for 5 hours, so that the height of the portion protruding from the base surface of the protrusion is 3 mm in height from the base surface. A base having 33 conical protrusions with a diameter of 2 mm was obtained. Moreover, the thickness and diameter excluding the protrusion at the base were 20 mm and 30 mm, respectively.

  Subsequently, a part of the obtained mixed granulated powder was put into a predetermined mold and press-molded by a uniaxial press apparatus, and a molded body different from the molded body was obtained. This molded body was sintered in an air atmosphere at a temperature of 1300 ° C. for 5 hours to obtain sintered bodies having a thickness and a diameter of 4.5 mm and 30 mm, respectively. The sintered body was subjected to drilling as a mechanical grinding process using a diamond electrodeposition tool (drill). As a result, a mask having a cylindrical hole, that is, a through-hole having a circular shape from the upper surface was obtained.

  Finally, the ZnO vapor deposition material shown in Table 1 was obtained by placing the mask on the upper surface of the base so that all the protrusions of the obtained base were accommodated in the through holes.

<Example 2>
A ZnO vapor deposition material was obtained in the same manner as in Example 1 except that a mask having a honeycomb-shaped through hole was obtained by cutting using a YAG laser.

<Example 3>
A ZnO vapor deposition material was obtained in the same manner as in Example 1 except that a mask having a through-hole with a lattice shape from the upper surface was obtained by a dry etching method using blasting.

<Comparative Example 1>
A ZnO vapor deposition material was obtained in the same manner as in Example 1 except that no mask was installed. That is, this vapor deposition material is equivalent to the base part which comprises the vapor deposition material of Examples 1-3.

<Comparative example 2>
A ZnO vapor deposition material was obtained in the same manner as in Example 1 except that no protrusion-like product was applied to the surface of the sintered body and no mask was installed. That is, no projection is formed on the vapor deposition material, and no mask is provided.

＜比較試験及び評価＞
実施例１〜３及び比較例１，２で得られた蒸着材、及び図６に示すＲＰＤ装置を用い、ガラス基材に蒸着膜を成膜した。その際、図５に示すように、プラズマ放電電流は、一定勾配αを５アンペア／分に設定し、蒸着材の昇華が開始するＡ値まで上昇させた。続いて２０アンペア（Ｂ値）まで低下させ、以降Ｂ値に固定して蒸着膜の成膜を行った。

<Comparison test and evaluation>
A vapor deposition film was formed on a glass substrate using the vapor deposition materials obtained in Examples 1 to 3 and Comparative Examples 1 and 2 and the RPD apparatus shown in FIG. At that time, as shown in FIG. 5, the plasma discharge current was increased to the A value at which the sublimation of the vapor deposition material started by setting the constant gradient α to 5 amperes / minute. Subsequently, it was lowered to 20 amperes (B value), and after that, the vapor deposition film was formed by fixing to the B value.

  The A value of the plasma discharge current at which sublimation of the vapor deposition material started, the degree of straight advancement of the vapor deposited material, the degree of adhesion of the vapor deposition material inside the apparatus, the occurrence of abnormal discharge, and the conductivity of the vapor deposition film were evaluated. These results are shown in Table 2 below. The degree of straightness was calculated by measuring the amount of deposition material sublimated passing through a fixed space above the deposition material by measuring the amount of deposition on the dummy substrate. That is, when the straightness is 100%, it means that the vapor deposition material that has been sublimated has passed 100% through this space. In FIG. 6, the constant space refers to a cylindrical space having a height from the hearth 64 to the base material 67 and a bottom surface of the inner diameter of the hearth. The degree of adhesion to the inside of the apparatus was shown as a relative ratio when the amount of deposition material deposited when vapor deposition was carried out using the deposition material of Comparative Example 1 at a specific site inside the apparatus. The presence or absence of abnormal discharge was evaluated as “Yes” when the current value increased or decreased by ± 50% or more with respect to the B value current. Furthermore, the electrical conductivity was measured by a 4-terminal 4-probe method using a constant current application at a so-called normal temperature at 25 ° C. using a Loresta (HP type, MCP-T410, probe in series 1.5 mm pitch) manufactured by Mitsubishi Chemical Corporation. It was measured.

表１及び表２から明らかなように、実施例１〜３と比較例１，２を比較すると、実施例１〜３では直進度が非常に高く、昇華した蒸着材料に十分な指向性が付与されていることが判る。その結果、実施例１〜３では比較例１，２よりも非常に付着度が低く、装置内部において余分に付着する蒸着材料も大幅に低減された。また、比較例２と比較すると、実施例１〜３では、突起の存在によって低エネルギーによる成膜が可能であったことから、異常放電も発生せず、膜に与えるダメージも少なかったため、高い導電率の蒸着膜を成膜することができた。

As is clear from Tables 1 and 2, when Examples 1 to 3 and Comparative Examples 1 and 2 are compared, Examples 1 to 3 have a very high degree of straightness and impart sufficient directivity to the sublimated vapor deposition material. It can be seen that As a result, in Examples 1 to 3, the degree of adhesion was much lower than in Comparative Examples 1 and 2, and the vapor deposition material adhering excessively inside the apparatus was also greatly reduced. Further, compared with Comparative Example 2, in Examples 1 to 3, since film formation with low energy was possible due to the presence of protrusions, abnormal discharge did not occur and damage to the film was small, so that high conductivity was achieved. It was possible to form a deposited film with a high rate.

DESCRIPTION OF SYMBOLS 10 Vapor deposition material 10a Base 10b Mask 11 Protrusion 12 Through-hole

Claims (6)

A vapor deposition material for forming a vapor deposition film by reactive plasma vapor deposition made using a metal oxide powder containing ZnO powder ,
The vapor deposition material (10) has a base (10a) having one or more protrusions (11) formed on the upper surface, and at least as many through holes (12) as the protrusions (11) correspond to the protrusions (11). A mask (10b) provided so that the through hole (12) accommodates all the protrusions (11) on the upper surface of the base (10a) provided at a position where
The protrusion (11) has a maximum height h from the surface of the base (10a) of 1 to 10 mm, and a maximum width w of a portion protruding from the surface of the base (10a) is 1 to 10 mm,
The through hole (12) provided in the mask (10b) has a height H that is 1.2 to 3 times the maximum height h of the protrusion (11) and a width W that is the maximum of the protrusion (11). Vapor deposition material characterized by being 1 to 4 times larger than w.   The protrusion (11) is obtained by sintering a sintered body formed in a conical or hemispherical shape using a material having the same composition as the material used for forming the base (10a), or by firing the material having the same composition. The vapor deposition material according to claim 1, comprising a pulverized product obtained by pulverizing the sintered body.   The vapor deposition material according to claim 1, wherein the protrusion (11) is formed by subjecting the surface of the base (10a) to mechanical grinding or chemical erosion.   The vapor deposition material according to any one of claims 1 to 3, wherein the mask (10b) is formed of a material having the same composition as that of the material used to form the base (10a).   The vapor deposition material according to any one of claims 1 to 3, wherein the mask (10b) is formed of a material having lower conductivity than the base portion (10a). Method of forming a deposited film had use the vapor deposition material according to any one of claims 1 to 5.

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