JP2011157592A - Oxide film and method for producing the same, and target and method for producing oxide sintered compact - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve the high performance of an oxide film as a p-type conductive film and a p-type transparent conductive film. <P>SOLUTION: The oxide film of one embodiment of the present invention is a film of an oxide consisting of titanium (Ti) and antimony (Sb) (possibly containing inevitable impurities). Further, in the number-of-atoms ratio of the antimony (Sb) to the titanium (Ti) in this oxide film, the number of atoms of the antimony (Sb) is 0.08 to 0.18 when the number of atoms of the titanium (Ti) is defined as 1. The oxide film is amorphous containing microcrystalline aggregate and containing microcrystal, or is amorphous with p-type conductivity. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an oxide film and a manufacturing method thereof, and a target and a manufacturing method of an oxide sintered body.

  Conventionally, various oxide films having transparency or conductivity have been studied. In particular, a film having both transparency and conductivity is called a transparent conductive film, and is widely used as an important element material in devices such as flat panel displays and solar cells.

  The typical transparent conductive film materials that have been adopted so far are ITO (indium tin oxide) and ZnO (zinc oxide). ITO (indium tin oxide) is known for its particularly high transparency and conductivity, and has been used for many years in various devices because it is stable as a material. However, the conductivity is limited to n-type, so the applicable range is limited. On the other hand, with regard to ZnO (zinc oxide), which has been attracting attention as an object of research and development for higher performance recently, not only pure zinc oxide, but also zinc oxide added with aluminum (Al) and chromium (Cr), etc. It has been developed (see Patent Document 1). However, zinc oxide is difficult to handle because it is less stable to moisture and heat than ITO.

By the way, there are many types of transparent conductive films exhibiting n-type conductivity, including the above-mentioned ITO, ZnO doped with Al, SnO ₂ doped with fluorine, and the like. However, it can be said that research and development for improving the performance of transparent conductive films exhibiting p-type conductivity are still halfway. For example, a CuAlO ₂ film that is a composite oxide of copper (Cu) and aluminum (Al), or a SrCu ₂ O ₂ film that is a composite oxide of copper (Cu) and strontium (Sr) is p-type conductivity. Is disclosed (see Non-Patent Document 1). However, their conductivity is very low. Further, in Patent Document 2 and Patent Document 3 shown below, it is disclosed that an oxide to which several elements are added has a property as a transparent conductive film. Since there is no specific disclosure regarding the conductivity and visible light transmittance of all the elements, it is difficult to adopt as a technical document of the transparent conductive film.

JP 2002-75061 A JP 2007-142028 A Special table 2008-507842

Jaroslaw Domaradzki and three others, "Transparent oxide semi-conductors based on TiO2 doped with V, Co and Pd elements-Vol. 23, Journal of Non-Crystal, Vol. 23, Vol.

  As described above, the performance of p-type conductive films, particularly oxide films as transparent conductive films, is currently far behind that of n-type. That is, the currently developed p-type transparent conductive film has a problem that the transparency or conductivity is mainly low.

  On the other hand, a crystalline oxide film may have a problem of crystal orientation control that determines its physical properties. In that sense, the adoption of a crystalline oxide film that does not fully exhibit its performance unless it has a specific crystal orientation is a technology for mass production and substrate enlargement with industrialization in mind. May be a potential barrier.

  The present invention greatly contributes to improving the performance of a p-type conductive film, particularly an oxide film as a p-type transparent conductive film, by solving at least one of the above technical problems. The inventors consider that it is indispensable to improve the performance of an oxide film having p-type conductivity in order to expand the application range of the conductive film, and have been studied for a long time in order to increase the conductivity or transparency. We tried to adopt not only the target elements but also new elements that had not been a subject of full-scale research. As a result of many trials and errors, the inventors have found that there is a material that exhibits completely different physical properties from the bulk physical properties by performing so-called thinning, and the properties of the film have solved the above-mentioned problems. It was found that it can contribute. Furthermore, as a result of repeated researches by the inventors, the material has relatively mild manufacturing conditions for obtaining the desired properties, and may have a very high degree of manufacturing freedom. I found out. The present invention has been created based on such knowledge and background.

  One oxide film of the present invention is an oxide film composed of titanium (Ti) and antimony (Sb) (which may contain inevitable impurities), and the above-described antimony (Sb) with respect to the above-described titanium (Ti). When the number ratio of the titanium (Ti) is 1 and the number of atoms of the antimony (Sb) is 0.08 or more and 0.18 or less, and an aggregate of microcrystals and microcrystals It is amorphous or contains amorphous and has p-type conductivity.

  According to this oxide film, it has p-type electrical conductivity and high transmittance can be obtained in the visible light region having a wavelength of 400 nm or more and 780 nm or less. In addition, this oxide usually shows crystallinity in a lump shape, but when it becomes a film shape, it becomes an aggregate of microcrystals, an amorphous state containing microcrystals, or an amorphous state, so that a film is formed on a large substrate. Is also suitable for industrial production.

  In addition, according to the method of manufacturing an oxide film of the present invention, a constituent atom of a target of an oxide (which may include inevitable impurities) composed of titanium (Ti) and antimony (Sb) is scattered on a substrate. A step of forming an aggregate of microcrystals, an amorphous state including microcrystals, or a first oxide film that is amorphous and has p-type conductivity.

  According to this method for producing an oxide film, an oxide film having p-type conductivity and high transmittance in the visible light region having a wavelength of 400 nm to 780 nm can be obtained. In addition, this oxide usually exhibits crystallinity in a lump shape, but when formed into a film shape, it becomes an aggregate of microcrystals, an amorphous state containing microcrystals, or an amorphous state, and thus is easily formed on a large substrate. Thus, an oxide film suitable for industrial production can be obtained. .

  One target of the present invention is an oxide (which may contain inevitable impurities) made of titanium (Ti) and antimony (Sb), and the atoms of the antimony (Sb) with respect to the titanium (Ti). As for the number ratio, when the number of titanium (Ti) atoms is 1, the number of antimony (Sb) atoms is 0.08 or more and 0.18 or less.

  According to this target, for example, the constituent material of this target is scattered by sputtering or pulse laser irradiation, thereby having p-type conductivity and a transmittance in the visible light region having a wavelength of 400 nm or more and 780 nm or less. A high oxide film can be formed.

  Moreover, the manufacturing method of one oxide sintered body of the present invention includes an oxide of antimony (Sb) (which may include inevitable impurities) and an oxide of titanium (Ti) (which may include inevitable impurities). When the ratio of the number of the above-mentioned antimony (Sb) to the above-mentioned titanium (Ti) is 1, the number of atoms of the antimony (Sb) is 0.08 or more and 0.18 or less. A mixing step for obtaining a mixture by mixing at a ratio, a forming step for obtaining a formed body by compression molding the mixture, and a sintering step for sintering the formed body by heating.

  According to this method of manufacturing an oxide sintered body, the oxide sintered body formed by this manufacturing method is used as a target to be irradiated with, for example, sputtering or pulsed laser, whereby a p-type electric An oxide film having conductivity and high transmittance in the visible light region with a wavelength of 400 nm to 780 nm can be formed. Moreover, since the handling in a market will become easy if it is a sintered compact, the product which is rich in distribution property and industrial applicability is obtained.

  In the present application, “substrate” typically means a glass substrate, a semiconductor substrate, a metal substrate, and a plastic substrate, but is not limited thereto. In addition, the “substrate” in the present application is not limited to a flat plate shape, and may include a curved structure. Further, in the present application, the “substrate temperature” means a set temperature of a heater that heats a table or an instrument that supports, holds, or accommodates the substrate, unless otherwise specified. In the present application, the “oxide” and the “oxide film” may contain impurities that cannot be avoided in manufacturing. In addition, the typical thing of this impurity is contained in the water utilized in the manufacturing process of the impurity which may be mixed when manufacturing a target, the impurity contained in various board | substrates, or various devices, for example. It is an impurity. Therefore, it cannot be necessarily detected by the latest analytical instrument at the time of filing this application. For example, aluminum (Al), silicon (Si), iron (Fe), sodium (Na), calcium (Ca), and magnesium ( Mg) is considered as a typical impurity.

  According to one oxide film of the present invention, it has p-type conductivity and high transmittance can be obtained in a visible light region having a wavelength of 400 nm or more and 780 nm or less. In addition, this oxide usually shows crystallinity in a lump shape, but when it becomes a film shape, it becomes an aggregate of microcrystals, an amorphous state containing microcrystals, or an amorphous state, so that a film is formed on a large substrate. Is also suitable for industrial production. In addition, according to the method for manufacturing an oxide film of the present invention, an oxide film having p-type conductivity and high transmittance in the visible light region having a wavelength of 400 nm to 780 nm can be obtained. In addition, this oxide usually exhibits crystallinity in a lump shape, but when formed into a film shape, it becomes an aggregate of microcrystals, an amorphous state containing microcrystals, or an amorphous state, and thus is easily formed on a large substrate. Thus, an oxide film suitable for industrial production can be obtained. In addition, according to one target of the present invention, for example, the constituent material of the target is scattered by sputtering or pulse laser irradiation, thereby having p-type electrical conductivity and having a wavelength of 400 nm or more and 780 nm or less. An oxide film with high transmittance in the light region can be formed. Furthermore, according to the manufacturing method of one oxide sintered body of the present invention, the oxide sintered body formed by this manufacturing method is utilized as a target to be irradiated with, for example, sputtering or pulse laser. Thus, an oxide film having p-type conductivity and high transmittance in the visible light region with a wavelength of 400 nm to 780 nm can be formed. Moreover, since the handling in a market will become easy if it is a sintered compact, the product which is rich in distribution property and industrial applicability is obtained.

It is explanatory drawing of the manufacturing apparatus of the 1st oxide film in the 1st Embodiment of this invention. It is explanatory drawing which shows one of the formation processes of the 2nd oxide film in the 1st Embodiment of this invention. It is explanatory drawing which shows one of the formation processes of the 2nd oxide film in the 1st Embodiment of this invention. It is a chart which shows the XRD (X-ray diffraction) analysis result of the 2nd oxide film in the 1st Embodiment of this invention. It is a chart which shows the analysis result of the transmittance | permeability of the light of the wavelength of the visible region of the 1st oxide film in the 1st Embodiment of this invention mainly. It is a chart which shows the analysis result of the transmittance | permeability of the light of the wavelength of the visible region mainly of the 2nd oxide film in the 1st Embodiment of this invention. It is a chart which shows the analysis result of the transmittance | permeability of the light of the wavelength of the visible region mainly of one 2nd oxide film in the modification (1) of the 1st Embodiment of this invention. It is a chart which shows the analysis result of the transmittance | permeability of the light of the wavelength of the visible region mainly of another 2nd oxide film in the modification (1) of the 1st Embodiment of this invention. It is a chart which shows the XRD (X-ray diffraction) analysis result of one 2nd oxide film in the modification (1) of the 1st Embodiment of this invention. It is a chart which shows the XRD (X-ray diffraction) analysis result of the comparative example in the 1st Embodiment of this invention. It is a chart which shows the XRD (X-ray diffraction) analysis result of the 2nd oxide film in the 2nd Embodiment of this invention.

  Embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this description, common parts are denoted by common reference symbols throughout the drawings unless otherwise specified. In the drawings, each element of each embodiment is not necessarily shown in a scale ratio. Moreover, in order to make each drawing easy to see, some reference numerals may be omitted.

<First Embodiment>
In this embodiment, an oxide film containing titanium (Ti) and antimony (Sb) as main components and a manufacturing method thereof will be described. FIG. 1 is an explanatory diagram of a first oxide film manufacturing apparatus in the present embodiment. 2A and 2B are explanatory diagrams showing one of the formation processes of the second oxide film in the present embodiment.

In the present embodiment, prior to the manufacture of the oxide film that is the final object, the oxide sintered body that is the raw material for forming the oxide film is manufactured. First, titanium dioxide (TiO ₂ ), which is an oxide of tetravalent titanium (Ti), and antimony pentoxide (Sb ₂ O ₅ ), which is an oxide of pentavalent antimony (Sb), are physically mixed. It was. In this embodiment, it mixed using the well-known Reika machine (Ishikawa factory make, model AGA). The above-mentioned two kinds of oxides were mixed so that the stoichiometric ratio of titanium (Ti) was 1 and antimony (Sb) was about 0.11. Note that titanium dioxide of the present embodiment _(TiO 2) _(rutile) is Kojundo Chemical Laboratory Co. nominal purity Corporation was employed those of 99.9%. Further, the _Sb 2 _{O 5} of the present embodiment, Kojundo Chemical Laboratory Co. nominal purity Corporation was employed those of 99.9%. By the way, in this embodiment, although each oxide is mixed by the above-mentioned ratio, this ratio is not limited to the above-mentioned numerical value. However, the oxide ratio of titanium (Ti) and the oxide of antimony (Sb), the atomic ratio of the above-mentioned antimony (Sb) to the above-mentioned titanium (Ti), the number of atoms of the titanium (Ti) is 1 When the number of atoms of the antimony (Sb) is 0.08 or more and 0.18 or less, the final oxide film can be manufactured with higher accuracy.

  Next, in this embodiment, the powder of the above-described oxide mixture is compression-molded by using a commercially available tablet molding machine (NPA Corporation, model TB-5H, thereby forming the above-mentioned oxide molding. The pressure applied at this time was 40 MPa, and the compact was placed on the above-mentioned powdery mixture placed on an alumina plate and heated to 1000 ° C. The first baking step for 4 hours was performed using a commercially available muffle furnace (manufactured by Motoyama Co., Ltd., model MS-2520.

  In the present embodiment, the molded product that has undergone the first firing step described above is further pulverized and mixed, and then compression-molded again to obtain a final oxide sintered body. The pressure applied at this time was 70 MPa, and the second baking step for 4 hours was performed using the above-described muffle furnace heated to 1500 ° C.

The relative density of the oxide sintered body obtained through the two firing steps described above was about 90%. The crystal structure of this oxide sintered body was measured and analyzed using an XRD analyzer (manufactured by Rigaku Corporation, product name “automatic X-ray explanation device RINT (registered trademark) 2400”). As a result, the above-mentioned oxide sintered body has a crystal structure of titanium dioxide (TiO ₂ ) doped with antimony (Sb), in other words, a rutile structure of (Ti _0.90 Sb _0.10 ) O _2. I found out. By the way, in this XRD measurement, the θ / 2θ method was adopted. Moreover, the tube voltage at the time of X-ray irradiation was 40 kV, and the tube current was 100 mA. Moreover, the target of the X-ray generation part was copper. In addition, any of the following XRD analysis was performed using the above-mentioned XRD analyzer.

Thereafter, as shown in FIG. 1, an oxide film is manufactured on the substrate 10 using a pulse laser deposition apparatus 20. The laser source of the pulse laser deposition apparatus 20 was a model Compex 201 manufactured by Lambda Physik, and the chamber thereof was a pulse laser deposition apparatus manufactured by Neocera. In the present embodiment, the substrate 10 is a borosilicate glass substrate. Further, the above oxide sintered body was adopted as the target 30. After mounting the substrate 10 on the stage (or substrate holder; hereinafter referred to as the stage) 27 in the chamber 21 that is open to the atmosphere, the substrate 10 is attached and mounted using a mounting bracket, and then a known vacuum pump 29 is installed. The air in the chamber 21 was exhausted from the exhaust port 28. After exhausting until the pressure in the chamber 21 was on the order of 10 ⁻⁴ Pa, the temperature of a heater (not shown) inside the stage 27 was set to 100 ° C.

After a while, oxygen (O ₂ ) was supplied into the chamber 21 from the oxygen gas cylinder 25a through the inlet. In the oxide film deposition step in this embodiment, the exhaust by the vacuum pump 29 was adjusted so that the equilibrium pressure of oxygen in the chamber 21 was about 1.5 Pa. In the present embodiment, only oxygen gas is introduced, but the present invention is not limited to this. For example, in addition to oxygen gas, an inert gas such as nitrogen (N ₂ ) gas, helium (He) gas, or argon (Ar) gas accommodated in the gas cylinder 25b shown in FIG. 1 may be introduced. . Further, although the equilibrium pressure of oxygen in the chamber 21 of the present embodiment is about 1.5 Pa, the oxide of the present embodiment is set even if other pressures (for example, 0.1 Pa or more and 100 Pa or less) are set. An oxide film similar to the film can be formed.

  Thereafter, a pulsed krypton fluoride (KrF) excimer laser (wavelength 248 nm) 22 is condensed by the lens 23 and then irradiated to the target 30. As shown in FIG. 2A, the first oxide film 11 is formed on the substrate 10 by scattering the constituent atoms of the target 30 made of the above-described oxide sintered body by the above-described excimer laser irradiation. Here, the composition ratio of the first oxide film 11 of this embodiment substantially matches that of the oxide sintered body that is the target 30. Accordingly, the composition ratio of titanium (Ti) is 1 and antimony (Sb) is about 0.11. The oscillation frequency of the excimer laser of this embodiment was 10 Hz, the energy per unit area of the unit pulse was 200 mJ per pulse, and the number of irradiations was 100,000.

Further, after the formation of the first oxide film 11, the substrate 10 was taken out from the chamber 21 opened to the atmosphere. Thereafter, the first oxide film 11 on the substrate 10 is heated to 2 at 100 ° C. in a chamber having about 1% hydrogen (H ₂ ) gas and about 99% nitrogen (N ₂ ) atmosphere. Heat treatment (annealing treatment) was performed for a time. As a result of this heat treatment, a second oxide film 12 was obtained on the substrate 10 as shown in FIG. 2B. Note that helium (He) or argon (Ar) gas may be used instead of the above-described nitrogen (N ₂ ). In the present embodiment, the first oxide film 11 is exposed to an atmosphere containing about 1% hydrogen (H ₂ ) gas. However, the reducing property represented by hydrogen gas or carbon monoxide (CO) gas is used. By exposing the first oxide film 11 to this gas, at least a part of the effect of this embodiment can be achieved.

  Here, the surface of the first oxide film 11 and the second oxide film 12 obtained in this embodiment is an atomic force microscope (AFM) (made by SII NanoTechnology Inc., model SPI-3700 / SPA- 300 "). As a result, the first oxide film 11 was a very flat film. The second oxide film 12 was also a flat film. Moreover, as a result of measuring the film thickness of the 2nd oxide film 12 using the said laser microscope, the film thickness was about 370 nm. Note that any of the following surface observations was performed using the aforementioned atomic force microscope.

  Further, XRD (X-ray diffraction) analysis was performed on the crystalline states of the first oxide film 11 and the second oxide film 12 described above. As a result, as shown in FIG. 3, in the first oxide film 11 and the second oxide film 12, peaks other than a broad halo peak considered to be derived from amorphous are observed at 20 ° to 30 °. There wasn't. Therefore, based on the result of the above-mentioned XRD analysis, the first oxide film 11 and the second oxide film 12 of this embodiment are both an aggregate of microcrystals that cannot be detected by XRD analysis, and an amorphous state containing microcrystals. Or is considered amorphous.

In addition, the electrical characteristics and conductivity of the first oxide film 11 and the second oxide film 12 described above are based on the Hall effect measurement device (product name “Hall Effect Measurement System HMS-3000 Ver. 3.5” manufactured by ECOPIA). ). As a result, the first oxide film 11 of this embodiment has n-type conductivity, and the conductivity thereof is about 4.37 × 10 ⁻³ S / cm. On the other hand, the second oxide film 12 of the present embodiment has p-type conductivity, and its conductivity is about 1.06 × 10 ⁻² S / cm. Therefore, it was found that the second oxide film 12 becomes an oxide film having p-type conductivity by the above heat treatment. The band gap of the second oxide film 12 was found to be about 3.1 eV. Therefore, it has been clarified that the second oxide film 12 of this embodiment has a considerably wide forbidden band width. In addition, any of the following electrical characteristics and conductivity measurements were performed using the Hall effect measuring apparatus described above.

  In addition, the visible light transmittance (hereinafter simply referred to as “visible light transmittance” or “transmittance”) of the first oxide film 11 and the second oxide film 12 described above is used as a multichannel spectrometer (Hamamatsu Photonics). The product name was analyzed using a product name “Multichannel Spectrometer PMA-12” manufactured by Co., Ltd. As the light detection element, a CCD linear image sensor “C1027-02” having a sensitivity wavelength range of 300 nm to 1100 nm was used. Note that any of the following visible light transmittance analyzes was performed using the aforementioned multichannel spectrometer.

  FIG. 4A is a chart showing the analysis result of the transmittance of light having a wavelength mainly in the visible light region of the second oxide film 12 in the present embodiment. FIG. 4B is a chart showing the analysis result of the transmittance of light having a wavelength mainly in the visible light region of the second oxide film 12 in the present embodiment.

  As shown in FIGS. 4A and 4B, the transmittance of light having a wavelength of 380 nm to 800 nm of the first oxide film 11 is 60% or more, and the light of a wavelength of 400 nm to 800 nm of the second oxide film 12 is used. The transmittance was 60% or more. Therefore, it became clear that both the first oxide film 11 and the second oxide film 12 in this embodiment have high transmittance.

  Furthermore, the surface roughness of the first oxide film 11 and the second oxide film 12 was analyzed by an atomic force microscope. As a result, the root mean square roughness (RMS) (hereinafter also simply referred to as “surface roughness”) of the surface of the first oxide film 11 in the present embodiment is about 2 nm, and the second oxide film 12 is. The surface roughness of was found to be about 6 nm. That is, it was found that the surfaces of the first oxide film 11 and the second oxide film 12 of this embodiment are extremely flat.

<Modification Example (1) of First Embodiment>
The second oxide film 12 was formed under the same conditions as in the first embodiment except that the heating temperature of the first oxide film 11 in the first embodiment was 50 ° C. or 200 ° C. Therefore, the description which overlaps with 1st Embodiment may be abbreviate | omitted.

First, as a result of analysis of electrical characteristics and conductivity, the second oxide film 12 when the first oxide film 11 is heat-treated at 50 ° C. has p-type conductivity and its conductivity. The rate was about 3.86 × 10 ⁻³ S / cm. In addition, the second oxide film 12 when the first oxide film 11 is heated at 200 ° C. has p-type conductivity, and its conductivity is about 8.77 × 10 ⁻³ S / cm. Met.

  In addition, the visible light transmittance was analyzed when the first oxide film 11 in the first embodiment was heat-treated at the above two temperatures. FIG. 4C is a chart corresponding to FIG. 4B of the second oxide film when the first oxide film 11 in this embodiment is heat-treated at 50 ° C. FIG. FIG. 4D is a chart corresponding to FIG. 4B of the second oxide film when the first oxide film 11 in this embodiment is heat-treated at 200 ° C.

  As shown in FIG. 4C, the transmittance of light having a wavelength of 415 nm or more and 800 nm or less of the second oxide film when the first oxide film 11 was heat-treated at 50 ° C. was 60% or more. As shown in FIG. 4D, the transmittance of light having a wavelength of 370 nm or more and 800 nm or less of the second oxide film when the first oxide film 11 was heat-treated at 200 ° C. was 60% or more. Furthermore, regarding the latter, the transmittance of light having a wavelength of 420 nm or more and 800 nm or less was 70% or more. Separately from this embodiment, the same high transmittance as that of this embodiment and the second oxide film 12 can be obtained by exposing the first oxide film 11 to an atmosphere containing hydrogen at 20 ° C. to 25 ° C. Is confirmed.

  Therefore, considering the analysis results of the first embodiment and the modification (1) of the first embodiment, first, the first oxide 11 is not particularly heat-treated, in other words, the room temperature ( It was found that use at 20 ° C. to 25 ° C. is preferable from the viewpoint of improving transmittance. In addition, when the results of additional analysis by the inventors are combined, it is found that exposure of the first oxide film 11 to an atmosphere containing hydrogen at 0 ° C. or more and 200 ° C. or less is also preferable from the viewpoint of improving transmittance. It was. The first oxide film 11 is more preferably heat-treated at 100 ° C. or higher and 200 ° C. or lower from the viewpoint of improving transmittance. In addition, in particular, when the heat treatment is performed at about 100 ° C. (error range is ± 3 ° C.), it is worthy of special mention that the conductivity of the p-type can be further increased. By the way, when the atomic ratio of antimony (Sb) to titanium (Ti) in the first oxide film 11 and the second oxide film 12 is 1, the antimony (Sb) If the number of atoms is 0.08 or more and 0.18 or less, the same effect as the above-described transmittance can be obtained.

  In addition, XRD analysis was performed when the first oxide film 11 in the first embodiment was heat-treated at the two temperatures described above. As a result, both 50 ° C. and 200 ° C. are considered to be an aggregate of microcrystals that cannot be detected by XRD analysis, an amorphous state including microcrystals, or an amorphous state, similar to the result of the present embodiment. Note that a chart of an XRD analysis result of the second oxide film when the heat treatment is performed for 2 hours under a condition of 200 ° C. is typically shown in FIG.

Separately from this embodiment, an XRD analysis in the case where the first oxide film 11 in the first embodiment is heat-treated at 500 ° C. was also performed as a comparative example. As a result, as shown in FIG. 6, when the first oxide film 11 is heated at 500 ° C., the diffraction peak of the crystal structure of anatase phase titanium dioxide (TiO ₂ ) (see the reference data in FIG. 6) It almost matches. Therefore, it has been clarified that the crystallization proceeds when the first oxide film 11 is heated at 500 ° C.

<Second Embodiment>
In the present embodiment, titanium dioxide (TiO ₂ ) and antimony pentoxide (Sb ₂ O ₅ ) are used as starting materials for an oxide sintered body for forming the first oxide film 11 of the first embodiment. Are mixed so that the stoichiometric ratio of titanium (Ti) is 1 and antimony (Sb) is about 0.087. The heating temperature of the first oxide film 11 for forming the second oxide film 12 was 200 ° C. Other than these, the process is the same as that of the first embodiment. Therefore, the description which overlaps with 1st Embodiment may be abbreviate | omitted.

Thereafter, similarly to the first embodiment, an oxide sintered body is manufactured through a compression molding process and a firing process by a tablet molding machine. The relative density of the oxide sintered body of the present embodiment is about 85%. As a result of XRD analysis of the oxide sintered body, it was found that the oxide sintered body had a rutile structure of (Ti _0.92 Sb _0.08 ) O ₂ .

Thereafter, similarly to the first embodiment, a first oxide film was manufactured on the substrate 10 using the pulse laser deposition apparatus 20 shown in FIG. The oxide sintered body having the rutile structure of (Ti _0.92 Sb _0.08 ) O ₂ described above was employed as the target 30.

Further, after the formation of the first oxide film 11, the first oxide film 11 on the substrate 10 is 2 under the condition of 200 ° C. in a chamber having a hydrogen (H ₂ ) gas atmosphere of about 1%. Heat treatment (annealing treatment) was performed for a time. As a result of this heat treatment, a second oxide film 12 was obtained on the substrate 10 as shown in FIG. 2B.

  Here, the surfaces of the first oxide film 11 and the second oxide film 12 obtained in the present embodiment were observed using an atomic force microscope. As a result, the first oxide film 11 was a very flat film. On the other hand, the second oxide film 12 was also a flat film. Moreover, as a result of measuring the film thickness of the second oxide film 12, the film thickness was about 700 nm.

  In addition, the inventors analyzed the crystal state of the first oxide film 11 and the second oxide film 12 described above by XRD (X-ray diffraction). As a result, as shown in FIG. 7, in the first oxide film 11 and the second oxide film 12, no peaks other than the halo peak considered to be derived from amorphous were observed at 20 ° to 30 °. . Therefore, the first oxide film 11 and the second oxide film 12 of the present embodiment are also the same as in the first embodiment, both of an aggregate of microcrystals that cannot be detected by XRD analysis, an amorphous state including microcrystals, Or it is considered to be amorphous.

In addition, the electrical characteristics and conductivity of the first oxide film 11 and the second oxide film 12 described above were analyzed. As a result, the first oxide film 11 of the present embodiment has p-type conductivity, and its conductivity is about 6.13 × 10 ⁻³ S / cm. Further, the second oxide film 12 of the present embodiment has p-type conductivity, and the conductivity thereof is about 3.94 × 10 ⁻³ S / cm.

  In addition, the visible light transmittance of the first oxide film 11 and the second oxide film 12 was also analyzed. As a result, it was confirmed that high transmittance (for example, 60% or more at a wavelength of 400 nm or more and 800 nm or less) can be obtained in the present embodiment as well as the result of the first embodiment.

  By the way, in each above-mentioned embodiment, although the 1st oxide film 11 is manufactured using the pulse laser vapor deposition apparatus 20, the manufacturing method of the 1st oxide film 11 is not limited to this. For example, a physical vapor deposition method (PVD method) represented by an RF sputtering method or a magnetron sputtering method can be applied.

  In addition, the composition ratio of the first oxide film 11 and the second oxide film 12 manufactured in each of the above-described embodiments is at least about the atomic ratio of antimony (Sb) to titanium (Ti). It can be said that it almost reflects the composition ratio of the oxide sintered body used. Therefore, when the atomic ratio of antimony (Sb) to titanium (Ti) in the first oxide film 11 and the second oxide film 12 is 1, the number of titanium (Ti) atoms is 1. If the number of atoms of antimony (Sb) is 0.08 or more and 0.18 or less, it can be said that it is preferable from the viewpoint of obtaining p-type conductivity or obtaining high visible light transmittance.

  Further, in each of the above-described embodiments, the temperature of the heater inside the stage 27 when the first oxide film 11 is manufactured using the pulse laser deposition apparatus 20 is set to 100 ° C., but this temperature is 100 ° C. Is not limited. For example, in order to obtain the first oxide film 11 with high flatness, it is preferable that the set temperature of the heater inside the stage 27 is 0 ° C. or higher and 100 ° C. or lower.

  Moreover, in each above-mentioned embodiment, although the oxide sintered compact is manufactured from the oxide as the target 30 for manufacturing the 1st oxide film 11 or the 2nd oxide film 12, hydroxide ( For example, the oxide sintered body may be manufactured from copper hydroxide), nitrate (for example, copper nitrate), carbonate, or oxalate.

  As described above, modifications that exist within the scope of the present invention including other combinations of the embodiments are also included in the scope of the claims.

  The present invention can be widely used as an oxide film having p-type conductivity or a transparent conductive film having p-type conductivity.

Claims (9)

An oxide film composed of titanium (Ti) and antimony (Sb) (which may contain inevitable impurities), wherein the atomic ratio of antimony (Sb) to titanium (Ti) is the number of atoms of titanium (Ti) Is 1 and the number of atoms of the antimony (Sb) is 0.08 or more and 0.18 or less, and an aggregate of microcrystals, an amorphous state including microcrystals, or an amorphous state and p-type conductivity Oxide film. The oxide film according to claim 1, which transmits light having a wavelength of 400 nm or more and 780 nm or less by 60% or more. Aggregates of microcrystals on the substrate, amorphous containing microcrystals, or amorphous by scattering target atoms of oxide (which may contain inevitable impurities) composed of titanium (Ti) and antimony (Sb) Forming a first oxide film having a p-type conductivity and a method for producing an oxide film. The oxide film according to claim 3, further comprising: forming a second oxide film by exposing the first oxide film to an atmosphere containing a reducing gas at 0 ° C. or more and 200 ° C. or less. Production method. The manufacturing method of the oxide film of Claim 3 or Claim 4 whose temperature of the said board | substrate when forming a 1st oxide film is 0 degreeC or more and 100 degrees C or less. The method for producing an oxide film according to claim 3 or 4, wherein the first oxide film is formed by scattering the constituent atoms of the target by sputtering or pulse laser irradiation. An oxide composed of titanium (Ti) and antimony (Sb) (which may contain inevitable impurities),
The number of atoms of the antimony (Sb) is 0.08 or more and 0.18 or less when the ratio of the number of the antimony (Sb) to the titanium (Ti) is 1 when the number of atoms of the titanium (Ti) is 1. The target according to claim 7, wherein the target is sintered and has a relative density of 75% or more. An antimony (Sb) oxide (which may contain unavoidable impurities) and a titanium (Ti) oxide (which may contain unavoidable impurities) have an atomic ratio of the antimony (Sb) to the titanium (Ti). A mixing step of obtaining a mixture by mixing in a proportion that the number of atoms of the antimony (Sb) is 0.08 or more and 0.18 or less when the number of atoms of titanium (Ti) is 1.
A molding step of obtaining a molded body by compression molding the mixture;
And a sintering step of sintering the molded body by heating.

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