Film-forming aid for chemical vapor deposition method, coating liquid for chemical vapor deposition method, metal oxide film, and method for forming metal oxide film

Abstract

The invention provides a coalescing agent for a chemical vapor deposition method. The coalescing agent contains a compound represented by a general formula (1): R1R2NCONH2, wherein R1 and R2 in the formula are respectively and independently hydrogen atoms, alkyl with 1-22 carbon atoms, amino or hydroxyl. The film-forming auxiliary agent for the chemical vapor deposition method has an excellent effect of improving the film-forming speed, and can obtain a metal oxide film with relatively small surface roughness.

Description

Technical Field

[0001] The present invention relates to a film-forming aid for chemical vapor deposition, a coating liquid for chemical vapor deposition, a metal oxide film and a film-forming method of the metal oxide film. Background Art

[0002] Chemical vapor deposition (CVD) is a film-forming method that is performed by a reaction of raw materials in the gas phase or a chemical reaction on a substrate. Since high vacuum is not required, it is suitable for mass production. Known methods include plasma CVD, atomic layer deposition (ALD), and organometallic CVD.

[0003] In addition, as another CVD method, atomized CVD is known as a film forming method for forming a metal oxide by converting a solution containing metal atoms into a mist consisting of droplets with a particle size of 500 μm or less by ultrasonic waves or the like, and reacting the mist on a substrate heated to 500° C. or less (for example, Patent Documents 1 to 3). Atomized CVD can form a film under atmospheric pressure, and since a micronized solution, i.e., mist, is used, a uniform and dense film can be formed on a substrate, so it is a particularly preferred film forming method.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-140352

[0007] Patent Document 2: Japanese Patent Application Publication No. 2018-172793

[0008] Patent Document 3: International Publication No. 2011 / 027425 Summary of the invention

[0009] 1. Technical issues to be resolved

[0010] To date, a lot of research has been conducted on metal oxide film formation using mist CVD. In order to obtain an industrially satisfactory film formation rate, research has been conducted on methods of forming films at high temperatures or heating the transported mist. However, the film formation rate is still not satisfactory.

[0011] Patent document 3 discloses a film forming method, wherein after a solution containing a metal salt or a complex of a metal element and ethylenediamine as a film forming aid is atomized, mist is supplied to a heated substrate, thereby forming a metal oxide film on the substrate. In the process of studying the formation of a low-resistance metal oxide film by adding a film forming aid, although an increase in the film forming speed was observed, it was still insufficient. Furthermore, there is also the possibility that the surface roughness of the film increases with the increase in the film forming speed, and the surface roughness deteriorates. Therefore, an excellent method is sought that does not deteriorate the surface roughness of the film while increasing the film forming speed.

[0012] The present invention has been made in view of the above-mentioned actual situation, and an object of the present invention is to provide a film-forming aid for chemical vapor deposition which has an excellent effect of increasing the film-forming rate and can obtain a metal oxide film with a small surface roughness.

[0013] Another object of the present invention is to provide a coating liquid for chemical vapor deposition containing the above-mentioned film-forming aid for chemical vapor deposition, a metal oxide film formed from the coating liquid, and a method for forming the metal oxide film.

[0014] (II) Technical solution

[0015] The present invention relates to a film-forming aid for chemical vapor deposition, which contains the general formula (1): R 1 R 2 The compound represented by NCONH2, wherein R 1 and R 2 Each is independently a hydrogen atom, a hydrocarbon group having 1 to 22 carbon atoms, an amino group or a hydroxyl group.

[0016] Furthermore, the present invention relates to a coating liquid for chemical vapor deposition containing a solution of the film-forming aid for chemical vapor deposition and a solution of a metal salt or a complex.

[0017] The present invention also relates to a metal oxide film formed from a solution of the film-forming aid for chemical vapor deposition and a solution of a metal salt or a complex, and having a film thickness of 0.1 μm to 20 μm.

[0018] In addition, the present invention relates to a method for forming a metal oxide film, which comprises the following steps: a step (a1) of separately atomizing a solution of the film-forming aid for chemical vapor deposition and a solution of a metal salt or a complex; and a step (b1) of simultaneously supplying the mist of the solution of the film-forming aid for chemical vapor deposition and the mist of the solution of the metal salt or the complex to a heated substrate surface.

[0019] The present invention also relates to a method for forming a metal oxide film, comprising the steps of: a step (a2) of atomizing the chemical vapor deposition coating liquid; and a step (b2) of supplying the obtained mist to a heated substrate surface.

[0020] (III) Beneficial effects

[0021] The film-forming aid for chemical vapor deposition of the present invention comprises the general formula (1): R 1 R 2 NCONH2 (R 1 and R 2 The compound represented by each independently being a hydrogen atom, a hydrocarbon group having 1 to 22 carbon atoms, an amino group or a hydroxyl group promotes the formation of a metal oxide film, thereby being able to obtain a metal oxide film having an excellent film formation rate and a small surface roughness. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of a metal oxide film forming apparatus in a method for producing a metal oxide film according to one embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of a metal oxide film forming apparatus in a method for producing a metal oxide film according to one embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of an atomizer of a metal oxide film forming apparatus in a method for producing a metal oxide film according to one embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of a mixing tank of a metal oxide film forming apparatus in a method for producing a metal oxide film according to one embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of a film forming section of a film forming apparatus for forming a metal oxide film in a method for producing a metal oxide film according to one embodiment of the present invention. DETAILED DESCRIPTION

[0027] Hereinafter, a chemical vapor deposition film-forming aid, a chemical vapor deposition coating liquid, a metal oxide film, and a method for forming a metal oxide film according to an embodiment of the present invention will be described with reference to the drawings as needed.

[0028] <Film-forming aids for chemical vapor deposition>

[0029] The film-forming aid for chemical vapor deposition (hereinafter also referred to as "CVD film-forming aid") contains the general formula (1): R 1 R 2 NCONH2 (R1 and R 2 Each of them is independently a hydrogen atom, a hydrocarbon group having 1 to 22 carbon atoms, an amino group or a hydroxyl group.

[0030] From the perspective of increasing film forming speed and reducing surface roughness, R in general formula (1) 1 and R 2 Preferably, each independently is a hydrogen atom. In addition, as the hydrocarbon group, linear alkyl, branched alkyl, aralkyl, etc. can be listed, among which linear alkyl and branched alkyl are preferred from the perspective of increasing the film forming speed. From the perspective of increasing the film forming speed, the number of carbon atoms is preferably 1 to 10, and more preferably 1 to 5. Among them, R is particularly preferred. 1 and R 2 In addition, an inclusion compound in which hydrogen peroxide or the like is included can also be used.

[0031] <Solution of film-forming aid for chemical vapor deposition>

[0032] From the perspective of mist generation efficiency, the film-forming aid for chemical vapor deposition is preferably a solution of a film-forming aid for chemical vapor deposition containing a compound represented by the general formula (1) and a solvent. As the solvent, any solvent can be used as long as it can dissolve the compound of the general formula (1), but from the perspective of mist generation efficiency, a solvent having a boiling point of 40°C or more and 150°C or less and a viscosity of 1.3 mPa·sec or less at 25°C is preferred, a solvent having a viscosity of 0.1 mPa·sec or more and 1.0 mPa·sec or less is more preferred, and a solvent having a viscosity of 0.5 mPa·sec or more and 1.0 mPa·sec or less is further preferred. In addition, as the solvent, there can be listed lower alcohols such as methanol, nitrile solvents such as acetonitrile, polar solvents such as water, and non-polar solvents such as aromatic solvents such as toluene. These solvents can also be used in combination of two or more. Among these solvents, polar solvents are preferred, and lower alcohols or water are more preferred from the point of view that the effect of the present invention can be fully obtained by acting as an oxidation source. Furthermore, it is preferred to contain water from the viewpoint of easy handling and preventing the atomized coating liquid from igniting. Here, the oxidation source refers to a supply source of oxygen atoms for converting the metal salt or complex described later into a metal oxide.

[0033] When the solvent is used, the compound represented by the general formula (1) is usually preferably in an amount of 0.1% by weight or more and 20% by weight or less, and more preferably in an amount of 0.5% by weight or more and 10% by weight or less, in the chemical vapor deposition film-forming aid.

[0034] <Metal salt or metal complex>

[0035] As a metal element constituting a metal salt or a metal complex, any metal element can be used as long as it can form an oxide film by chemical vapor deposition. As a metal element, it is preferably selected from one or more of the group IIIA elements, the group IVA elements and the transition metal elements. As the group IIIA elements, Al, Ga, In, etc. can be listed. In addition, as the group IVA elements, Si, Ge, Sn, Pb, etc. can be listed. In addition, as the transition metal element, d-block elements can be listed. From the perspective of ease of acquisition, Al, Si, Zr, and Y are more preferred as metal elements.

[0036] The salt or complex of the metal element may be any salt or complex as long as it can form an oxide film by chemical vapor deposition, for example, salts or complexes of metals such as tri(acetylacetonate)aluminum, polysilazane, tetra(acetylacetonate)zirconium, and (acetylacetonate)yttrium.

[0037] <Solution of metal salt or metal complex>

[0038] From the perspective of fog production efficiency, the metal salt or complex is preferably a solution of a metal salt or complex containing a metal salt or complex and a solvent. As the solvent, any solvent can be used as long as it can dissolve the compound serving as the metal salt or complex. From the perspective of fog production efficiency, a solvent having a boiling point of 40°C or more and 150°C or less is preferred, and a solvent having a boiling point of 50°C or more and 125°C or less is more preferred. In addition, a solvent having a viscosity of 1.3 mPa·sec or less at 25°C is preferred, a solvent having a viscosity of 0.1 mPa·sec or more and 1.0 mPa·sec or less is more preferred, and a solvent having a viscosity of 0.2 mPa·sec or more and 0.8 mPa·sec or less is further preferred. In addition, as the solvent, there can be listed lower alcohols such as methanol, nitrile solvents such as acetonitrile, polar solvents such as water, and non-polar solvents such as aromatic solvents such as toluene. Two or more of these solvents can be mixed and used. In addition, when the solution of the film-forming aid for chemical vapor deposition does not contain a solvent that acts as an oxidation source, as a solvent for the metal salt or complex, lower alcohols or water are more preferred from the point of being able to more fully obtain the effect of the present invention. When a non-polar solvent is used, a compatible lower alcohol can be used, or only water can be atomized and introduced into the mixer for use.

[0039] The solution of the metal salt or complex contains the metal salt or complex and the solvent, and preferably contains 0.2 wt % or more and 20 wt % or less of the metal salt or complex. If the metal salt or complex is less than 0.2 wt %, the film forming rate is reduced, and if it is more than 20 wt %, the surface roughness of the metal oxide layer may increase.

[0040] <Coating liquid for chemical vapor deposition method>

[0041] The coating liquid for chemical vapor deposition contains a solution of the film-forming aid for chemical vapor deposition and a solution of the metal salt or complex. The coating liquid for chemical vapor deposition only needs to contain the film-forming aid for chemical vapor deposition, the metal salt or complex, and their respective solvents.

[0042] <Method for forming metal oxide film>

[0043] The metal oxide film may be formed by chemical vapor deposition, and mist chemical vapor deposition (hereinafter also referred to as "mCVD") is preferred from the viewpoint of excellent film formation speed and uniformity of film formation.

[0044] As mCVD, for example, there can be listed: a method for forming a metal oxide film having a step (a1) of atomizing the solution of the film-forming aid for chemical vapor deposition and the solution of the metal salt or complex, and a step (b1) of simultaneously supplying the mist of the solution of the film-forming aid for chemical vapor deposition and the mist of the solution of the metal salt or complex to the surface of a heated substrate; a method for forming a metal oxide film having a step (a2) of atomizing the coating liquid for chemical vapor deposition, and a step (b2) of supplying the obtained mist to the surface of a heated substrate, etc. More specifically, fine particles obtained by atomizing the raw material are supplied to the surface of the substrate using a carrier gas, and then the fine particles are reacted in an atmosphere at a temperature of 200°C to 500°C. By making the raw material into fine particles and reacting them, a metal oxide film with a fast film forming speed and a small surface roughness can be obtained.

[0045] Figure 1 A schematic diagram of a film forming apparatus (1) in a method for forming a metal oxide film having a step (a1) of separately atomizing a solution of the film forming aid for chemical vapor deposition and a solution of the metal salt or complex is shown in the figure. The film forming apparatus (1) is formed by connecting two atomizers (misting devices), a mixing tank and a film forming machine (film forming unit) using a pipe.

[0046] Figure 2 The schematic diagram of the film forming device (2) in the film forming method of the metal oxide film is shown in the figure, which has the step (a2) of atomizing the coating liquid for chemical vapor deposition and the step (b2) of supplying the obtained mist to the surface of the heated substrate. The film forming device (2) is formed by connecting an atomizer (misting device) and a film forming machine (film forming unit) through a pipe.

[0047] Figure 3A schematic diagram of an atomizer in a film-forming device for a metal oxide film is shown in FIG. The atomizer is composed of a container for loading a raw material and an ultrasonic generator having an ultrasonic vibrator. The container has a Teflon (registered trademark) lid and a bottom formed of a polypropylene or tetrafluoroethylene-hexafluoropropylene copolymer film on a glass cylinder. Two glass pipes are provided on the lid in a manner penetrating the lid. The first pipe is provided for the purpose of conveying a carrier gas (nitrogen) for carrying mist into the container, and the second pipe is provided for the purpose of conveying the mist and the carrier gas generated in the container to a film-forming machine. The container is placed in an ultrasonic generating device together with water, and the ultrasonic wave generated by the ultrasonic vibrator is transmitted to the raw material via water and a film made of polypropylene, etc., thereby atomizing the raw material.

[0048] Figure 4 A schematic diagram of a mixing tank in a film forming device for a metal oxide film is shown in FIG. The mixing tank is provided with a Teflon (registered trademark) cover on a glass container. Three glass pipes are arranged on the cover in a manner of penetrating the cover. Among the three pipes, two pipes are connected to two atomizers through pipes, respectively, and one pipe arranged in the center is connected to the film forming part through a pipe. The mist generated by the atomizer is transported to the film forming part via the mixing tank. The mixing tank is mainly used to mix the mist generated in each atomizer.

[0049] Figure 5 The schematic diagram of the film forming section in the film forming device of the metal oxide film is shown in FIG. The film forming section is composed of a metal jig (jig) connected from an atomizer or a mixing tank and a heating plate. The jig is connected to the atomizer or the mixing tank through a silicone tube and is provided for the purpose of heating the mist and the substrate. When the heated mist passes over the substrate, a chemical reaction occurs on the substrate to form a metal oxide film. In addition, Figure 5 In the present invention, if a jig with a large internal space is used, film formation can be performed not only on a plate-shaped substrate but also on a three-dimensional substrate. The above-mentioned heating plate is provided for the purpose of heating the jig.

[0050] In order to suppress oxidation of the substrate surface, the carrier gas is preferably an inert gas that does not contain 10,000 ppm (volume ratio) or more of oxygen.

[0051] As the material of the substrate, for example, aluminum, stainless steel, zinc, copper, silicon, graphite, glass, etc. can be cited. In addition, as the shape of the substrate, it is not particularly limited as long as it is in the form of a plate or a block, and is preferably a plate-like substrate such as an aluminum plate or a glass plate, a silicon wafer, or a graphite sheet.

[0052] In the mCVD method, the metal oxide layer is preferably formed by heating and reacting a mist of a raw material on a substrate in a temperature atmosphere of 200°C to 500°C, and more preferably at 300°C to 410°C.

[0053] In the raw materials of the mCVD method, if the metal salt or complex is set as (A), the compound represented by the general formula (1) is set as (B), and water is set as (C), then from the perspective of being able to obtain a metal oxide film with a small surface roughness at a high film formation rate, the molar ratio of (A) to (B) ((B) / (A)) is preferably 0.01 to 17, more preferably 0.3 to 10, and even more preferably 0.5 to 5. Furthermore, from the perspective of film formation rate and surface roughness, the molar ratio of (B) to (C) ((C) / (B)) is preferably 1 to 250, more preferably 60 to 180, and even more preferably 100 to 180.

[0054] In the raw materials of the mCVD method, from the perspective of being able to obtain a metal oxide film with a small surface roughness at a high film forming speed, in 100 parts by weight of the total weight of (A), (B) and (C), preferably (A) is 1.7 parts by weight or more and 90 parts by weight or less, more preferably 1.7 parts by weight or more and 50 parts by weight or less, preferably (B) is 0.2 parts by weight or more and 65 parts by weight or less, more preferably 1.2 parts by weight or more and 65 parts by weight or less, and preferably (C) is 5 parts by weight or more and 96 parts by weight or less. At this time, from the perspective of effectively forming a film, the total amount of the solvent is preferably 100 parts by weight or more and 1400 parts by weight or less, more preferably 100 parts by weight or more and 1000 parts by weight or less, and further preferably 100 parts by weight or more and 800 parts by weight or less, relative to 100 parts by weight of the total weight of (A), (B) and (C).

[0055] The metal oxide film is formed from the solution of the chemical vapor deposition film-forming aid and the solution of the metal salt or complex, and has a film thickness of 0.1 μm to 20 μm.

[0056] Example

[0057] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[0058] <Preparation Example>

[0059] <Preparation of film-forming aids for CVD, solutions of metal salts or complexes, and coating solutions for chemical vapor deposition>

[0060] According to the raw materials and the blending amounts described in Tables 1 to 3, a solution of a CVD film-forming aid, a solution of a metal salt or a complex, and a coating solution for chemical vapor deposition were prepared.

[0061] [Table 1]

[0062]

[0063] In Table 1, Al(acac)3 represents tris(acetylacetonate)aluminum ("Aluminum Chelate A", manufactured by Kawaken Fine Chemicals Co., Ltd.);

[0064] Y(acac)3 represents yttrium tris(acetylacetonate) trihydrate (manufactured by Mitsuwa Chemicals Co., Ltd.);

[0065] Zr(acac)4 represents tetrakis(acetylacetonate)zirconium (manufactured by Tokyo Chemical Industry Co., Ltd.);

[0066] The polysilazane refers to TRESMILE ANN120-20 (manufactured by SANWA KAGAKU CORP.).

[0067] [Table 2]

[0068]

[0069] In Table 2, b-1 represents urea (in the general formula (1), R 1 and R 2 is a hydrogen atom);

[0070] b-2 represents urea (in the general formula (1), R 1 and R 2 is a hydrogen atom) (inclusion complex with hydrogen peroxide);

[0071] b-3 represents ethyl urea (in the general formula (1), R 1 is CH3CH2, R 2 is a hydrogen atom);

[0072] b-4 represents 1-decylurea (in the general formula (1), R 1 CH3C9H 18 , R 2 is a hydrogen atom);

[0073] b-5 represents semicarbazide (in the general formula (1), R 1 is amino, R 2 is a hydrogen atom);

[0074] b-6 represents hydroxyurea (in the general formula (1), R 1 is hydroxyl group, R 2 is a hydrogen atom);

[0075] b-7 represents 1,1-dimethylurea (in the general formula (1), R 1 CH3, R 2 is CH3).

[0076] [Table 3]

[0077]

[0078] <Example 1>

[0079] <Formation of metal oxide film on substrate>

[0080] 《Device Preparation》

[0081] use Figure 1 and Figures 3-5The film-forming device (atomizing CVD device) shown in the figure forms a metal oxide film on a substrate by the following method. A polypropylene or tetrafluoroethylene-hexafluoroethylene copolymer film is fixed at a position 1 cm away from the bottom of a glass cylinder (diameter 13 cm, height 15 cm) using an O-ring and a sealant. A Teflon (registered trademark) cover is set on the upper part of the cylinder, two holes are punched in the cover, and glass pipes for nitrogen supply and mist transportation are inserted. The cylinder is immersed in a water bath, and three ultrasonic vibrators (ultrasonic atomization unit HMC-2401; manufactured by Honda Electronics Co., Ltd.) are set directly below the polypropylene or tetrafluoroethylene-hexafluoroethylene copolymer. The above is used as an atomizer and two units are prepared. A Teflon (registered trademark) cover is set on a glass cylindrical container, three holes are punched in the cover, and glass pipes (2 pieces) for connecting the atomizer and the film-forming part are inserted. The above is used as a mixing tank, and connected to two atomizers using a 1.5m silicone tube. Install a substrate (30×30×0.5mm, single-sided polished Al plate, manufactured by TDC CO., LTD., Ra=3~5nm) on the heating plate in the film forming part. The above is used as the film forming part, and connected to the mixing tank using a 1.5m silicone tube. Inject 200mL of the metal salt or complex solution A-1 into the atomizer 1, and inject 100mL of the CVD film-forming aid solution B-1 into the atomizer 2. Let nitrogen (oxygen concentration is less than 1ppm) flow from the nitrogen supply pipe of the atomizer to the exhaust hole of the film forming part at 11L / min (5.5L / min for each atomizer) for 20 minutes. Then, use a heating plate to heat until the metal material temperature reaches 360°C. After confirming that the substrate temperature was stable at 360° C., the ultrasonic oscillators of atomizers 1 and 2 were operated to atomize the solution of the metal salt or complex and the solution of the CVD film-forming aid for 20 minutes to form a metal oxide film.

[0082] Manufacturing Conditions

[0083] The ultrasonic vibrator was operated at a frequency of 2.4 MHz, a DC voltage of 24 V, and a current of 0.6 A. Table 4 shows the metal salt or complex solution, CVD film-forming aid solution, and substrate used.

[0084] <Examples 2 to 13, Comparative Examples 1 to 9>

[0085] In Examples 2 to 13 and Comparative Examples 1 to 9, samples were prepared by the same operation as in Example 1, except that the conditions for forming the metal oxide film of Example 1 were changed to the conditions shown in Tables 4 and 5 (substrate, metal salt or complex solution, CVD film-forming aid solution, film-forming temperature). In Comparative Examples 1, 2, 4 to 9, no CVD film-forming aid was contained, and only water was used.

[0086] <Examples 14 to 16, Comparative Examples 10 to 12>

[0087] In Example 14 and Comparative Examples 10 and 11, a solution of a metal salt or complex and a solution of a CVD film-forming aid were mixed in advance by the following operation to prepare a coating solution for chemical vapor deposition, and a film was formed using the coating solution.

[0088] <Formation of a metal oxide film on a substrate using a coating liquid>

[0089] 《Device Preparation》

[0090] use Figure 2 , 3 and the film-forming device (atomizing CVD device) shown in 5, a metal oxide film is formed on the substrate by the following method. Using an O-ring and a sealant, a polypropylene or tetrafluoroethylene-hexafluoroethylene copolymer film is fixed at a position 1 cm away from the bottom of a glass cylinder (diameter 13 cm, height 15 cm). A Teflon (registered trademark) cover is set on the upper part of the cylinder, two holes are punched in the cover, and glass pipes for nitrogen supply and mist transportation are inserted. The cylinder is immersed in a water bath, and three ultrasonic vibrators (ultrasonic atomization unit HMC-2401; manufactured by Honda Electronics Co., Ltd.) are set directly below the polypropylene or tetrafluoroethylene-hexafluoroethylene copolymer. The above is used as an atomizer and one is prepared. A substrate (30×30×0.5mm) is installed on the heating plate in the film-forming section. The above is used as the film-forming section and connected to the atomizer using a 1.5m silicone tube. 200 mL of coating liquid D-1 was injected into the atomizer, and nitrogen (oxygen concentration was 1 ppm or less) was flowed from the nitrogen supply pipe of the atomizer to the exhaust hole of the film forming part at 5.5 L / min for 20 minutes. Then, the metal material was heated using a heating plate until the temperature of the metal material reached 360° C. After confirming that the substrate temperature was stable at 360° C., the ultrasonic vibrator of the atomizer was operated to atomize the coating liquid for 20 minutes to form a metal oxide film.

[0091] Manufacturing Conditions

[0092] The ultrasonic vibrator was operated at a frequency of 2.4 MHz, a DC voltage of 24 V, and a current of 0.6 A. Table 6 shows the coating liquid and substrate used.

[0093] The samples obtained above were evaluated as follows. The results are shown in Tables 4 to 6.

[0094] <Measurement of Film Thickness of Metal Oxide Film>

[0095] Regarding the measurement of the film thickness of the metal oxide film, chrome glass was used instead of the metal material of Example 1, and each metal oxide film was formed on the chrome glass, and the measurement was performed using a reflection spectroscopic film thickness measuring instrument (F20; manufactured by Filmetrics, Inc.). It was assumed that each metal oxide film was formed on the chrome glass and the metal substrate with the same film thickness. In addition, in order to obtain an accurate film thickness, it is necessary to calculate the film thickness based on the refractive index data. The same sample was observed in advance using an ellipsometer (UVISEL Plus; manufactured by HORIBA, Ltd.) to calculate the refractive index.

[0096] <Evaluation of the effect of increasing film formation speed>

[0097] Regarding the effect of improving the film formation rate, the film formation rate was calculated by dividing the film thickness (μm) obtained by the film thickness measurement by the time (minutes) required for film formation, and the relative film formation rate was calculated based on the film formation rate of the system not containing the compound represented by the general formula (1). The case where the relative film formation rate was 2 or more was evaluated as "◎", the case where it was less than 2 and 1.5 or more was evaluated as "○", the case where it was less than 1.5 and 1.1 or more was evaluated as "△", and the case where it was less than 1.1 was evaluated as "×". Examples 1 to 10 and Comparative Examples 2 to 3 were evaluated based on Comparative Example 1 (for example, film formation rate of Example 1 / film formation rate of Comparative Example 1), and Example 11 and Comparative Example 5 were evaluated based on Comparative Example 4, and Example 12 and Comparative Example 7 were evaluated based on Comparative Example 6, and Example 13 and Comparative Example 9 were evaluated based on Comparative Example 8, and Example 14 and Comparative Example 11 were evaluated based on Comparative Example 10. Examples 15 and 16 were evaluated based on Comparative Example 12.

[0098] <Evaluation of the effect of reducing the surface roughness of the film>

[0099] The surface roughness (Ra) (unit: Å) of the metal oxide film was measured using a contact surface roughness meter (DektakXT-S; manufactured by Bruker Japan Co., Ltd.). The center of the substrate of 0.5 mm was measured to calculate the surface roughness (arithmetic mean roughness) and the standard deviation of the surface roughness. Regarding the effect of reducing the surface roughness of the film, these values ​​were used to calculate the multiplier of the surface roughness and the multiplier of the standard deviation of the surface roughness based on the values ​​of the system (surface roughness and standard deviation of surface roughness) that do not contain the compound represented by the general formula (1). The case where the multiplier of the surface roughness is less than 0.8 is evaluated as "◎", the case where it is greater than 0.8 and less than 1.0 is evaluated as "○", the case where it is greater than 1.0 and less than 1.2 is evaluated as "△", and the case where it is greater than 1.2 is evaluated as "×". The multiplier of the standard deviation of the surface roughness is also evaluated based on the above-mentioned benchmark. Examples 1 to 10 and Comparative Examples 2 to 3 were evaluated based on Comparative Example 1 (e.g., surface roughness of Example 1 / surface roughness of Comparative Example 1), Example 11 and Comparative Example 5 were evaluated based on Comparative Example 4, Example 12 and Comparative Example 7 were evaluated based on Comparative Example 6, Example 13 and Comparative Example 9 were evaluated based on Comparative Example 8, and Example 14 and Comparative Example 11 were evaluated based on Comparative Example 10. Example 15 and Example 16 were evaluated based on Comparative Example 12.

[0100] In addition, in Tables 4 to 6, surface roughness (Å) / film thickness (μm) and standard deviation of surface roughness / film thickness (μm) are shown as reference.

[0101] [Table 4]

[0102]

[0103] [Table 5]

[0104]

[0105] [Table 6]

[0106]

[0107] Since the compounds represented by the general formula (1) are added to form films in Examples 1 to 10, the film forming speed is improved and the surface roughness is improved compared to Comparative Example 1 which does not contain the compound represented by the general formula (1). This is due to the effect of the film-forming aid for CVD containing the compound represented by the general formula (1). In addition, compared with Example 1, Examples 3 and 4 use a film-forming aid with a higher concentration of the compound represented by the general formula (1) for film formation. Although Example 5 is a metal oxide film obtained by changing the type of solvent for film formation, the film forming speed shows the same result as that of Example 1. Although Example 6 is a metal oxide film obtained by using a film-forming aid with a higher concentration of a metal salt or complex in a solution of a metal salt or complex for film formation, the film forming speed shows the same result as that of Example 1. In Examples 7 to 10, compounds represented by the general formula (1) of various structures are used for film formation, and the results are the same as those of Example 1, showing good film forming speed and surface roughness.

[0108] Comparative Example 2, in which the film was formed at a higher temperature than Comparative Example 1, had a slightly improved film forming rate, but poor surface roughness. Comparative Example 3, in which ethylenediamine was used as a CVD film forming aid, had poor film forming rate and surface roughness.

[0109] Since the compounds represented by the general formula (1) were added to form the films in Examples 11 to 13, the film forming speed was improved and the surface roughness was improved compared with Comparative Examples 4, 6 and 8 which did not contain the compounds represented by the general formula (1). In addition, Comparative Examples 5, 7 and 9 which were formed at a temperature higher than that of Comparative Examples 4, 6 and 8 had a slightly improved film forming speed, but the surface roughness was deteriorated.

[0110] In Example 14, since a coating liquid for chemical vapor deposition containing a solution of a film-forming aid for chemical vapor deposition containing a compound represented by the general formula (1) and a solution of a metal salt or a complex is used for film formation, the film formation speed is improved and the surface roughness is improved compared with Comparative Example 10 which does not contain a compound represented by the general formula (1). In Comparative Example 11 which is formed at a temperature higher than that of Comparative Example 10, the film formation speed is slightly improved, but the surface roughness is deteriorated.

[0111] Since Examples 15 to 16 use a coating liquid for chemical vapor deposition that includes a solution of a film-forming aid for chemical vapor deposition containing a compound represented by the general formula (1) and a solution of a metal salt or a complex to form a film, the film forming speed is improved and the surface roughness becomes better compared to Comparative Example 12 that does not contain the compound represented by the general formula (1).

Claims

1. A film-forming aid for chemical vapor deposition, comprising the general formula (1): R 1 R 2 The compound represented by NCONH2, wherein R 1 and R 2 Each is independently a hydrogen atom, a hydrocarbon group having 1 to 22 carbon atoms, an amino group or a hydroxyl group.

2. A coating liquid for chemical vapor deposition, comprising a solution of the film-forming aid for chemical vapor deposition according to claim 1 and a solution of a metal salt or a complex. 3 . A metal oxide film, which is formed from a solution of the film-forming aid for chemical vapor deposition according to claim 1 and a solution of a metal salt or a complex, and has a film thickness of 0.1 μm to 20 μm.

4. A method for forming a metal oxide film, comprising the following steps: A step (a1) of separately atomizing the solution of the chemical vapor deposition film-forming aid and the solution of the metal salt or complex according to claim 1; and A step (b1) of simultaneously supplying the mist of the solution of the chemical vapor deposition film-forming aid and the mist of the solution of the metal salt or complex to the heated surface of the substrate.

5. A method for forming a metal oxide film, comprising the following steps: A step (a2) of atomizing the chemical vapor deposition coating liquid according to claim 2; and A step (b2) of supplying the obtained mist to the heated surface of the substrate.

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