JPH07268637A - Composition for formation of metal oxide thin film pattern and its formation - Google Patents

Abstract

PURPOSE:To efficiently form a negative type sharp metal oxide thin film pattern at a low cost by a small number of stages requiring no resists, to reduce the amt. of applied energy of an active line compared to the case in which fine particles are not dispersed and moreover to reduce the amt. of hydrolyzable metallic compounds. CONSTITUTION:Fine particles are dispersed into a soln. contg. one or >= two kinds of hydrolyzable metallic compounds selected from hydrolyzable organic metallic compounds (such as metal alkoxide) and metal halides, a water generating agent releasing water by the irradiation of an actinic ray (such as 2- nitroethanol) and, if required, an acid generating agent releasing acid by the irradiation of an actinic ray (such as an onium salt). The surface of a substrate is coated with the same dispersion. The obtd. photosensitive film is irradiated with an actinic ray for forming a picture. After that, it is developed by water or an alcohol solvent to remove a nonexposed part, and the substrate is subjected to heat treatment to convert the remaining film into metal oxide, by which a negative type metal oxide thin film pattern is formed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a metal oxide thin film pattern forming composition which is sensitive to actinic rays such as ultraviolet rays, electron beams, ion beams or X-rays, and a metal oxide thin film pattern forming composition using the same. And how to do.

[0002]

2. Description of the Related Art A metal oxide thin film is used in various devices as a capacitor film, an optical waveguide, an optical element, etc. due to its electrical and optical properties. When a metal oxide thin film is used in a device, it is generally necessary to pattern the thin film so as to form a predetermined circuit.

Conventionally, pattern formation of a metal oxide thin film has been
After forming a thin film of a metal oxide on a substrate by a method such as a CVD method, a sputtering method, or a sol-gel method, a resist is applied, and if necessary, the resist film is dried by heating,
It has been carried out through a normal resist patterning process including image forming exposure by radiation, development of a resist, etching of a metal oxide on an exposed portion, and removal of the resist.

[0004]

In the conventional thin film pattern forming method using a resist, (a) the process is complicated and the cost is high.

(B) When the thin film is a complex metal oxide, a specific element is selectively etched, resulting in a deviation of the composition of the obtained thin film.

(C) For etching metal oxides, it is necessary to use a chemical such as a strong acid, which is troublesome in waste liquid treatment.

There are problems such as the above.

An object of the present invention is to use a resist without using
It is to provide a composition capable of forming a metal oxide thin film pattern on a substrate and a thin film pattern forming method.

Another object of the present invention is to provide a composition for forming a metal oxide thin film pattern and a method for forming the thin film pattern, which is capable of forming a thin film pattern by irradiation with a small amount of energy of actinic rays.

[0010]

The composition for forming a metal oxide thin film pattern of the present invention comprises a solution containing a hydrolyzable metal compound and a photosensitizer which releases water upon irradiation with actinic rays. It is formed by dispersing fine particles of an oxide or a substance that becomes an oxide by firing.

The method of forming a metal oxide thin film pattern of the present invention comprises applying the composition according to claim 1 or 2 onto a substrate, exposing the resulting coating film to image formation with actinic rays, and developing with a solvent. After removing the unexposed portion by heat treatment, the film in the exposed portion is converted into a metal oxide by heat treatment.

The present invention will be described in more detail below.

The hydrolyzable metal compound used in the present invention is preferably a hydrolyzable organometallic compound or a metal halide.

The hydrolyzable organometallic compound is not particularly limited as long as it can form a metal hydroxide by hydrolysis, and typical examples thereof include metal alkoxides, metal acetylacetonate complexes, and metals. Mention may be made of carboxylates. The metal alkoxide is preferably a lower alkoxide such as ethoxide, propoxide, isopropoxide, butoxide and isobutoxide. Similarly, the metal carboxylate is also preferably a lower fatty acid salt such as acetate or propionate.

As the metal halide, chloride or the like can be used.

For each metal element, one or more hydrolyzable metal compounds can be used as raw materials.

The metal of the hydrolyzable metal compound is not particularly limited, and a hydrolyzable metal compound corresponding to the intended thin film of metal oxide may be selected.

The compositions and methods of the present invention include lead zirconate titanate (PZT), lanthanum-containing lead zirconate titanate (PLZT), strontium titanate (STO), barium titanate (BTO), and barium strontium titanate (PZT). BSTO), bismuth titanate (Bi ₄ Ti ₃
O _12), tantalum oxide (Ta ₂ O _5), titanium dioxide (TiO _2), lead oxide (PbO), zirconium dioxide (ZrO _2), alumina (Al ₂ O _3), tin dioxide (SnO _2), ruthenium dioxide It can be suitably used for forming a thin film pattern of a metal oxide (including both a composite metal oxide and a single metal oxide) such as (RuO ₂ ). Of course, to form a thin film of these metal oxides, a hydrolyzable organometallic compound and / or metal halide of the metal of these metal oxides is used.

The composition of the present invention may contain, as the hydrolyzable metal compound, only one of the hydrolyzable organometallic compound and the metal halide, or may contain both of them.

As the water generating agent for generating water for hydrolyzing the hydrolyzable metal compound, o-nitrobenzyl alcohol, 2-nitroethanol, formaldehyde, tartaric acid, 2-hydroxybenzyl alcohol, 2
-Carboxybenzyl alcohol, 2-carboxybenzaldehyde, 2-nitrobenzaldehyde, phthalic acid and the like are preferable.

The water-generating agent used in the present invention is irradiated with actinic rays and undergoes a dehydration reaction to generate water.

In the composition of the present invention, in order to further accelerate the hydrolysis reaction of the hydrolyzable metal compound by the water-generating agent, in addition to the water-generating agent, a photosensitizing agent (hereinafter , Acid generator). When an acid generator coexists, the acid generated by the irradiation of actinic rays in the exposed area acts as a catalyst for the curing reaction of the hydrolyzable metal compound, and the curing is further promoted. It is possible to further increase the difference in solubility with the parts and further reduce the irradiation dose.

As the acid generator usable in the present invention in combination with the water generator, those conventionally known in the field of photoresists can be used. Examples include onium salts such as iodonium salts and sulfonium salts; organic halides such as halogen-containing benzene derivatives, halogen-substituted alkanes and cycloalkanes, halogen-containing s-triazine or isocyanurate derivatives;
Alternatively, aromatic sulfonic acid esters such as p-nitrobenzyl ester, benzene polysulfonic acid ester, bisarylsulfonyldiazomethane, 2-phenylsulfonylacetophenone, and sulfonyl compounds can be used.

The water-generating agent and the acid-generating agent may be used either individually or in combination of two or more.

The composition of the present invention comprises these hydrolyzable metal compound and water-generating agent (and optionally an acid-generating agent).
The fine particles are dispersed in the solution.

The fine particles may be a metal oxide,
It may be a substance that becomes an oxide by firing (for example, a hydroxide or a salt insoluble in a solvent described later).

The fine particles may have the same composition as the metal oxide produced from the hydrolyzable metal compound,
It can be different.

The particle size of the fine particles is preferably as small as possible in order to prevent scattering of actinic rays. When ultraviolet rays are used as actinic rays, the particle size of the fine particles is preferably 1500 Å or less, particularly 750 Å or less.

The content ratio of the fine particles is such that the oxide derived from the fine particles in the oxide produced from the composition of the present invention is 50% by weight or less, particularly 30 to 1% by weight. It is suitable.

In the composition for forming a metal oxide thin film pattern of the present invention, a hydrolyzable metal compound as a raw material is used as a suitable organic solvent (eg, alcohols such as ethanol, isopropanol, 2-methoxyethanol; acetic acid, propionic acid, etc.). It can be prepared by dissolving it in a lower aliphatic carboxylic acid, etc.), adding a water-generating agent (or a water-generating agent and an acid-generating agent) to the resulting solution, and then dispersing the fine particles. In addition, you may perform dissolution and dispersion together. When the target is a complex oxide thin film pattern,
Two or more kinds of hydrolyzable metal compounds that are raw materials are used in a proportion that matches the abundance ratio of each metal in the target product.

The concentration of the hydrolyzable metal compound in the composition is preferably within the range of 1 to 20% by weight. The amount of the water generating agent added is 0.001 to 20% by weight, preferably 0.1 to 10% by weight, based on the total weight of the composition.

If the amount of the water-generating agent added is too small, the difference in solubility between the exposed and unexposed areas does not increase and a clear pattern cannot be formed. If the amount of the water-generating agent added is too large, the coating film on the surrounding unexposed area will be modified by irradiation, and a sharp pattern cannot be obtained. When an acid generator is also used in combination, the addition amount of the acid generator is 0.001 to 20% by weight, preferably 0.1 to 1% by weight based on the total weight of the composition.
It is within the range of 0% by weight. In this case, the total amount of the water generating agent and the acid generating agent is preferably 20% by weight or less based on the total weight of the composition.

The resulting solution contained a chelate-forming compound such as acetylacetone, ethanolamine, or ethyl oxobutanoate as a stabilizer for preventing gelation during storage in an amount of 0.1% with respect to 1 mol of the hydrolyzable metal compound. 05-1
You may add in the ratio of 0 mol.

Further, a dispersant may be added in order to enhance the stability of fine particle dispersion. This dispersant is appropriately selected from anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. The amount of the dispersant added is preferably 10 to 0.001% by weight of the fine particles, and more preferably 3 to 0.05% by weight.

In order to disperse the fine particles in this solution, it is preferable to add the fine particles and mix them in a ball mill, but other methods may be used.

The coating of this composition on a substrate is not particularly limited as long as it is a coating method capable of forming a coating film having a uniform film thickness, but a spin coating method is often employed industrially. If necessary, the coating operation can be repeated after the coating film has gelated to obtain a desired coating film thickness. In the present invention, since it is possible to irradiate with a small amount of energy by adding a water-generating agent, it is possible to thicken the coating film.
Generally, the film thickness of the metal oxide thin film formed using the composition of the present invention is preferably in the range of 0.01 to 0.2 μm.

The coating film obtained loses its fluidity after being left for a short time and can be exposed. The standing time may be determined so that the coating film is dried (loss of fluidity) to the extent that actinic radiation for image formation is possible, and is usually in the range of several seconds to several minutes.

Next, imagewise exposure is performed with active rays to form an image corresponding to the desired pattern. The actinic ray is generally an ultraviolet ray, an electron beam, an ion beam, an X-ray or the like, though it depends on the photosensitizer (water generating agent, acid generating agent). The ultraviolet source may be, for example, a low pressure mercury lamp, an excimer laser, or the like. Image forming exposure is carried out by a conventional method.
It can be carried out by a direct writing method in which an actinic ray is irradiated through a mask, or when the actinic ray source is a laser, a patterned laser beam is irradiated. The amount of irradiation energy is not particularly limited, and is usually 100 mJ / cm ² or more, though it varies depending on the film thickness and the type of the photosensitizer.

By the irradiation of this actinic ray, the above-mentioned curing reaction hydrolysis reaction and polymerization reaction of the coating film proceed in the exposed portion, the coating film becomes hard and dense, and the solubility in a solvent such as alcohol decreases. . In the present invention, since the water-generating agent is present, the curing reaction in the exposed area can be selectively promoted with a small amount of actinic ray irradiation energy. for that reason,
Not only those having a very high energy density such as electron beams, but also ultraviolet rays having a lower energy density than those can sufficiently achieve the purpose of irradiation. When an acid generator coexists in the coating film, the acid generated in the exposed area further accelerates the curing reaction of the coating film.

If desired, after this irradiation, the temperature may be 1 to 10 at 40 to 100 ° C. in a dry inert gas (N ₂ , Ar, etc.) atmosphere.
You may leave it for about a minute. By thus blocking the water content in the air and maintaining the temperature, the curing reaction of the coating film in the exposed area can be selectively promoted while suppressing the hydrolysis of the coating film components in the unexposed area. The difference in solubility between the exposed area and the unexposed area is further increased.

After irradiation, the coating film may be dried by heating the entire surface of the substrate, if necessary. This allows
Moisture and organic solvent remaining in the exposed area that remains as a pattern are removed. This total heating is, for example, 100
It may be performed at about 150 ° C for about 5 to 10 minutes.

After that, by developing with an appropriate solvent to remove the uncured coating film in the unexposed area, a negative pattern composed of the exposed area is formed on the substrate.
The solvent used as the developer may be any solvent that can dissolve the material in the unexposed area and has a low solubility in the cured film in the exposed area. Preference is given to using water or alcohols. Suitable alcohols include alkoxy alcohols such as 2-methoxyethanol, 2-ethoxyethanol. In this case, if the dissolving power is too high and dissolution of the exposed portion may occur, the dissolving power can be adjusted by adding an alkyl alcohol such as ethyl alcohol or isopropyl alcohol (IPA) to the above alcohol. As described above, it is not necessary to use a strong corrosive acid such as a mixed acid of hydrofluoric acid / hydrochloric acid for development, and it is possible to perform development with a solvent such as alcohol which is not corrosive and is safe and inexpensive. This is one of the major advantages.

The development is performed, for example, in a solvent at room temperature for 10 seconds to 1 second.
It can be carried out by soaking for about 0 minutes. The developing conditions are set so that the unexposed portion is completely removed and the exposed portion is not substantially removed. Therefore, the development conditions vary depending on the dose of actinic radiation, the presence or absence of subsequent heat treatment, and the type of solvent used for development.

After removing the unexposed area by development, rinsing with a suitable organic solvent which has no or little solubility in the exposed area to prevent excessive dissolution of the coating film. Is preferred. As the rinse liquid, for example, esters (eg, ethyl acetate), ketones (eg, methyl ethyl ketone, methyl isobutyl ketone), hydrocarbons (eg, toluene, n-hexane) and the like can be used. Alcohol having a relatively small polarity such as isopropyl alcohol can also be used as the rinse liquid.

In this way, a negative type coating film pattern in which the exposed portion remains is formed on the substrate. Then, the substrate is heat-treated to completely convert the metal compound in the coating film into a metal oxide, whereby a thin film pattern made of a metal oxide having a desired composition is obtained. This heat treatment is usually 300-80 in the air.
It is preferable to perform firing at 0 ° C. for 1 second to 2 hours.

If necessary, a different type or the same type of metal oxide thin film pattern may be formed on the metal oxide thin film pattern thus formed by the same method.

[0047]

The hydrolyzable metal compound in the composition of the present invention is
It reacts with water to be hydrolyzed, and gels through a sol of hydrous metal oxide. When the reaction proceeds further, a three-dimensional cross-linking polymerization reaction occurs due to a metal-oxygen bond to cure the film.

The composition of the present invention contains a photosensitizer which liberates water upon irradiation with actinic rays, and water is generated from the water-generating agent upon irradiation with actinic rays to cause a hydrolysis reaction of the hydrolyzable metal compound. Is promoted. Therefore, the curing reaction of the film significantly progresses in the exposed area, and the difference in solubility between the exposed area and the unexposed area becomes very large.

When the composition of the present invention contains an acid generator, an acid is generated by irradiation with actinic rays, and the above-mentioned hydrolysis reaction and polymerization reaction are remarkably promoted by the catalytic action of the acid.

Since the composition of the present invention contains fine particles of an oxide or a substance which becomes an oxide by firing, it contains an oxide produced from a hydrolyzable metal compound and an oxide derived from the fine particles. A film is formed. A film having a large film thickness can be easily formed by containing the fine particles.

Further, in the method of the present invention, the irradiation energy of actinic rays is less than that in the case of using a composition containing no fine particles, and therefore the exposure time can be shortened.

In the method of the present invention, a coating film of this composition is formed, imagewise exposed and then contacted with a solvent.
As a result, the unexposed portion is removed. Then, by heat treatment, the product of the exposed portion becomes a thin film of metal oxide.

As the hydrolyzable organometallic compound,
When a compound having the property of being polymerized by actinic radiation is used, the polymerization reaction proceeds along with the above-mentioned hydrolysis reaction, and this also reduces the solubility in the solvent (compared to the unirradiated one).

[0054]

EXAMPLES Examples will be shown below, but these do not limit the present invention. The mask used in the examples is a line-and-space photomask with a line width of 10 μm (width 1
It was a mask in which 0 μm lines were arranged at 10 μm intervals.

The metal oxide thin film patterns formed in the examples were evaluated by measuring the line width of the thin film patterns by microscopic observation. When the measured line width (average value at 10 points) is within ± 5% of the line width of the mask pattern, the formed thin film pattern is considered to be good.
The case in which there was a membrane defect of more than% was regarded as impossible.

(Example 1) This experiment exemplifies formation of a thin film in which SiO ₂ serves as a matrix and fine particles of ITO (indium tin oxide) are dispersed therein.

First, IT having a particle size of 0.05 μm or less
O fine particles were manufactured by the following method. Indium trichloride and tin tetrachloride were coprecipitated and hydrolyzed in pure water to obtain hydroxide powder. This powder was fired at 800 ° C. for 1 hour to obtain an In ₂ O ₃ powder containing 10 wt% SnO _2, that is, an ITO powder. Classify this powder with a sieve to obtain a particle size of 0.05μ
The ITO powder was m or less.

Tetraethyl orthosilicate (TE
5 g of OS) is dissolved in 9 g of isopropanol, 0.87 cc of dilute hydrochloric acid (0.1 N) is added to carry out partial hydrolysis, and the concentration is adjusted with isopropanol so that the weight of the solid (SiO ₂ ) is 7%. It was

1 g of ITO fine powder was added to 100 g of this solution.
g, and stirred with a ball mill for 100 hours to uniformly disperse the ITO fine powder to obtain a uniform solution. 0.5 g of o-nitrobenzyl alcohol was added to this solution, and the concentration was adjusted with ethanol so that the solid content became 5%.
A TO powder dispersion film forming agent was prepared.

1% of this dispersion liquid on Vycor glass
It was applied by spin coating under the conditions of 000 rpm and 30 seconds to prepare a coating film. After leaving this coating film at room temperature for 1 minute, deep ultraviolet rays (center wavelength 25
4 nm) was applied to the coating film through a mask pattern. The irradiation dose was ² J / cm ² , and the mask used had a line width of 10
Line-and-space photomask of μm (width 10μ
It was a mask in which m lines were arranged at 10 μm intervals. After the irradiation with ultraviolet rays, the substrate was heated in a dryer at 100 ° C. for 1 minute to be dried. Then, for development, the substrate was immersed in an etching solution (2-methoxyethanol) at room temperature for 1 minute to completely dissolve and remove the unexposed portion of the coating film. Then, the substrate was immersed in IPA (isopropyl alcohol) as a rinse solution at room temperature for 5 seconds.

After that, baking was performed at 150 ° C. for 10 minutes in the air atmosphere, and at 400 ° C. for 10 minutes in the air atmosphere to form an ITO dispersed SiO ₂ film pattern having a film thickness of about 3000 Å. The surface resistance of this film is 3.4 × 10 ⁷ Ω /
It was □.

Example 2 In this experiment, PbZr _0.52 Ti was used.
_It illustrates the formation of a negative PZT thin film pattern having a composition of _0.48 O ₃ .

First, PZT fine particles having the same composition as this were manufactured as follows.

Lead acetate, zirconium butoxide and titanium isopropoxide were dissolved in 2-methoxyethanol,
When it became uniform, pure water was added. Concentrate this solution,
After drying to dryness, the obtained powder is calcined at 700 ° C. for 1 hour to obtain PZ.
T powder was obtained. This powder was crushed and classified by a sieve.

The particle size of the fine particles is 700Å.

[0066] lead acetate _{[Pb (CH 3 COO) 2} · 3
H ₂ O] 12.25 g and 2-methoxyethanol 70 g
, And heated to 140 ° C. for sufficient dehydration. To this solution, commercially available zirconium n-butoxide [Zr (O
(CH ₂ ) ₃ CH ₃ ) ₄ ] 6.87 g and titanium isopropoxide [Ti (OCH (CH ₃ ) ₂ ) ₄ ] 4.09 g
And added. Thereafter, as the water generating agent 2-nitro ethanol _{(C 2 H 5 NO 3)} 2.9g was added, the whole mass was diluted with as 2-methoxyethanol becomes 105.2 g.

Next, to 100 g of this solution, 1 g of fine particles was added, diluted with the same amount of 2-methoxyethanol as the solution, and mixed. All the fine particles were uniformly dispersed.

The atomic ratio of each metal in the metal oxide thin film pattern forming composition thus prepared (hereinafter referred to as coating liquid) was Pb: Zr: Ti = 1: 0.52: 0.48.

This coating solution was applied on a platinum substrate by a spin coating method at 1000 rpm for 30 seconds to form a coating film. After leaving this coating film at room temperature for 1 minute, the coating film was irradiated with deep ultraviolet rays (center wavelength 254 nm) using a low pressure mercury lamp as a light source through a mask pattern. Irradiation amount is 2J /
cm ² and the mask used was a line-and-space photomask with a line width of 10 μm (a line with a width of 10 μm is 10
The masks were arranged at intervals of μm). After the irradiation with ultraviolet rays, the substrate was heated in a dryer at 100 ° C. for 1 minute to be dried. Then, for development, the substrate was immersed in an etching solution (2-methoxyethanol) at room temperature for 1 minute to completely dissolve and remove the unexposed portion of the coating film. Next, the substrate is rinsed with IP of rinse solution.
It was immersed in A (isopropyl alcohol) at room temperature for 5 seconds. Then, baking was performed at 400 ° C. for 10 minutes in the air atmosphere and further at 500 ° C. for 60 minutes in the air atmosphere to form a PZT negative thin film pattern having a film thickness of about 1000 Å.

It was confirmed by X-ray diffraction that the obtained PZT thin film had a perovskite structure, and by EPMA and XPS analysis that it had a composition of PbZr _0.52 Ti _0.48 O ₃ . The thin film pattern obtained was good.

Similar results were obtained when the KrF excimer laser generating a single wavelength of 249 nm was used as the ultraviolet ray source at the same dose. Further, in this example, the ultraviolet irradiation energy was 500 mJ / cm ² or more (more preferably 1000 mJ / cm ² or more), and a good negative PZT thin film pattern could be formed.

Furthermore, even when the solvent used for development was changed to a mixed solution of 2-methoxyethanol and IPA (mixing ratio was 1: 1 by volume ratio), the same good negative pattern was obtained.

(Examples 3 to 9) P was carried out in the same manner as in Example 2 except that the water generating agent shown in Table 1 was used and the irradiation amount of ultraviolet rays, the etching solution and the etching time were as shown in Table 1.
A ZT thin film was formed. As a result, good thin film patterns were obtained in all cases. It was confirmed that this thin film also had a perovskite structure and had a composition of PbZr _0.52 Ti _0.48 O ₃ .

[0074]

[Table 1]

Comparative Example 1 A PZT thin film pattern was formed in the same manner as in Example 2 except that the water-generating agent 2-nitroethanol was not added to the composition. There is almost no difference in solubility between the unexposed area and the unexposed area, and even after development with water, 2-methoxyethanol or a mixed solvent of 2-methoxyethanol and IPA after heating and drying, the unexposed area is selectively removed. I couldn't.

(Comparative Example 2) (Comparative example in the case of not adding fine particles) A composition (solution) was prepared in the same manner as in Example 2 except that fine particles were not added to the composition. It was applied in the same manner as in Example 2. Then, the exposure amount of ultraviolet rays is set to 120.
A thin film was formed in the same manner as in Example 1 except that the thickness was 0 mJ / cm ² . The thickness of the obtained thin film was 600Å.

(Examples 10 to 23) A solution containing the hydrolyzable metal compound shown in Table 2 and a solvent was prepared in the same manner as in Example 2. (When two or more kinds of hydrolyzable organometallic compounds are used, their mixing ratio was made to match the metal stoichiometric ratio of the target metal oxide.) In this solution, 2- Nitroethanol was added at 2% by weight of the solution.

Next, the oxide fine particles having the same composition as the target composition are dispersed so that the proportion of the total amount of the oxides derived from the hydrolyzable organometallic compound is 5%, and the oxide having the target composition is obtained. A coating solution for forming a thin film was prepared. The average particle diameter of the fine particles used was about 500 Å or less.

Using this coating solution, a metal oxide thin film pattern was formed in the same manner as in Example 1. The coating thickness was about 1000Å in each case, the development was performed with 2-methoxyethanol, and the rinse was performed with n-hexane. In each case, a good negative type thin film pattern made of the metal oxide having the composition shown in Table 2 could be obtained after firing.

[0080]

[Table 2]

(Example 24) (Example in which an acid generator was used in combination) In preparing the solution of Example 2, the acid generator
Phenylsulfonylacetophenone [C ₆ H ₅ SO ₂ C
H ₂ COC ₆ H ₅ ] 0.5 g was added and dissolved, and coating and ultraviolet irradiation were performed in the same manner as in Example 1.
The ultraviolet irradiation dose was 1 J / cm ² . After UV irradiation and drying, it was immersed in 2-methoxyethanol for 1 minute for development. Then, it was immersed in IPA as a rinse liquid and baked in the same manner as in Example 2 to obtain a good negative type pattern made of an oxide thin film (PZT thin film) having a film thickness of about 1000 Å. The perovskite type PZT was confirmed by X-ray diffraction analysis.

The same good negative pattern was obtained when the KrF laser was used as the ultraviolet ray source or when the solvent used for development was a mixed solvent of 2-methoxyethanol and IPA. .

[0083]

According to the present invention, a negative type metal oxide thin film pattern can be formed by using the sol-gel method without using a resist. Efficiency can be achieved. In addition, since the sol-gel method is used, film formation can be performed efficiently at low cost, the area can be easily increased, and there is almost no difference in composition, as compared with vapor phase methods such as CVD and sputtering.

Further, in the present invention, since the water-generating agent is allowed to exist in the coating film, it becomes possible to form a pattern with a small irradiation energy, and a clear pattern can be obtained by using an industrial ultraviolet irradiation device. . Further, since the development can be performed with a relatively safe and inexpensive liquid such as alcohol which is not corrosive, the waste liquid treatment is easy.

If an acid generator is present in addition to the water generator, it becomes possible to form a pattern with a smaller irradiation energy.

In the present invention, since the fine particles are dispersed in the composition, the irradiation energy amount of the actinic rays can be reduced as compared with the case where the fine particles are not added. It is also possible to reduce the amount of hydrolyzable metal compound used.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masa Yonezawa 1-297 Kitabukuro-cho, Omiya-shi, Saitama Mitsubishi Materials Corporation Central Research Laboratory (72) Katsumi Ogi 1-297 Kitabukuro-cho, Omiya-shi, Saitama Mitsubishi Materials Central Research Institute Co., Ltd.

Claims (3)

[Claims] 1. A metal obtained by dispersing fine particles of an oxide or a substance that becomes an oxide by firing in a solution containing a hydrolyzable metal compound and a photosensitizer that releases water upon irradiation with actinic rays. A composition for forming an oxide thin film pattern. 2. The composition for forming a metal oxide thin film pattern according to claim 1, wherein the solution further contains a photosensitizer that liberates an acid upon irradiation with actinic radiation. 3. The composition according to claim 1 or 2 is applied onto a substrate, the resulting coating film is imagewise exposed with actinic radiation, and developed with a solvent to remove the unexposed portion, followed by heat treatment. A method of forming a metal oxide thin film pattern, which comprises converting a film in an exposed portion into a metal oxide.