JPH0823152A - Patterning method - Google Patents

Abstract

(57) [Summary] [Objective] A mask pattern made of a metal oxide is formed without using an organic resist to simplify the patterning process. [Structure] After forming a first film 2 on a substrate 1 (or directly without forming it), a photosensitive second film 3 is formed, and the second film 3 is used as a predetermined mask pattern. Then, dry etching is performed to pattern the first film 2 (or the substrate 2). A composition containing a hydrolyzable metal compound and a photosensitizer that releases water upon irradiation with actinic rays is applied to form a second film 3, and the second film 3 is imagewise exposed with actinic rays. Then, after developing with a solvent to remove the unexposed portion, heat treatment is performed to convert the film in the exposed portion into a metal oxide to form a mask pattern. [Effect] Since the mask pattern can be formed by using the sol-gel method without using a resist, the manufacturing process can be shortened and the efficiency can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a patterning method by dry etching used in a manufacturing process of semiconductor devices. More specifically, the present invention relates to a patterning method that is an improved method of forming a mask pattern for dry etching.

[0002]

2. Description of the Related Art As a conventional example in which a predetermined pattern is formed on a substrate by dry etching, Japanese Patent Laid-Open No. 17517/1993 is known.
An example of the method for forming the metal pattern described in Japanese Patent No. 4 will be described with reference to FIG.

First, as shown in FIG. 3A, a metal film 12 is formed on a substrate 11, and an inorganic film 13 is formed thereon.
Further, an organic resist film 1 for ordinary photolithography
4 is deposited.

Next, the resist film 14 formed is exposed to light.
A development process is performed to form a resist mask 14A made of a resist film as shown in FIG. Subsequently, the inorganic film 13 is removed by reactive ion etching or the like, and the mask pattern 13 made of the inorganic film is formed as shown in FIG.
Form A.

Then, the resist mask 14A is removed as shown in FIG. 3D by an asher process using oxygen plasma. Next, the metal film 12 is etched by dry etching using a halogen gas to obtain the state shown in FIG. After that, the mask pattern 13A of the remaining inorganic film is removed if necessary.

In JP-A-60-243284, a method of directly forming an inorganic film 13 on a substrate 11 and then forming a resist film 14 thereon as shown in FIG. 4 (a). Is listed. In this case, the exposure of the resist film 14
The resist mask 14A is formed by development as shown in FIG. 3B, and then the resist mask 14A is formed by ion etching or the like.
A mask pattern 13A made of an inorganic film as shown in FIG.
Is formed. Then, asher processing is performed as shown in FIG.
After removing the resist mask 14A as shown in (d), a dry etching process is performed. As a result, as shown in FIG. 4E, the surface 11A itself of the substrate 11 is patterned (roughened) according to a predetermined pattern.

[0007]

In the above conventional method, the process is complicated and the cost is increased because the resist film 14 is formed.

An object of the present invention is to form a mask pattern made of a metal oxide without using an organic resist,
Accordingly, it is to provide a patterning method in which the process is simplified.

[0009]

According to a patterning method of a first aspect, a photosensitive second layer is formed after a first film is formed on a substrate.
Film is formed, and the second film is formed into a predetermined mask pattern, and then the first film is etched according to the mask pattern by performing a dry etching process to form a target pattern derived from the first film. In the patterning method for allowing the second film to remain on the substrate, a composition containing at least a hydrolyzable metal compound and a photosensitizer that liberates water upon irradiation with actinic rays is used as the first film. When the second film is patterned by coating on the film, the second film is imagewise exposed with actinic rays and developed with a solvent to remove the unexposed portion, followed by heat treatment. Then, the film of the exposed portion is converted into a metal oxide, whereby the mask pattern made of the metal oxide is formed.

The patterning method of claim 2 is the method of claim 1.
In above, the composition is characterized by further containing a photosensitizer which liberates an acid upon irradiation with actinic radiation.

According to a third aspect of the patterning method, a photosensitive film is formed on a substrate, the photosensitive film is used as a predetermined mask pattern, and a dry etching process is performed to etch the surface of the substrate according to the mask pattern. In the patterning method for forming a concave portion of a target pattern on the surface of the substrate, the photosensitive film contains at least a hydrolyzable metal compound and a photosensitizer that liberates water upon irradiation with actinic rays. When the photosensitive film is formed by coating the photosensitive film on the substrate, and the photosensitive film is patterned, the photosensitive film is imagewise exposed with actinic rays and developed with a solvent to remove the unexposed portion, It is characterized in that the film of the exposed portion is converted into a metal oxide by heat treatment, thereby forming the mask pattern made of the metal oxide.

The patterning method according to claim 4 is the method according to claim 3.
In above, the composition is characterized by further containing a photosensitizer which liberates an acid upon irradiation with actinic radiation.

The present invention will be described in detail below with reference to the drawings.

1 (a) to 1 (d) are sectional views showing an embodiment of the patterning method according to claim 1, and FIGS.
(C) is sectional drawing which shows the one Example method of the patterning method of Claim 3.

In the method shown in FIGS. 1A to 1D, the first film 2 to be patterned is first formed on the substrate 1.
Evaporation method, sputtering method, CVD method, MOCVD
Method, MBE method, sol-gel method or the like.

As the first film 2, Si, Ge, C
Semiconductor or compound semiconductor film such as aAs, InP, GaN; Al, Al alloy such as Al—Cu alloy, Ti, Nb,
Ta, Cr, Mo, W, Ni, Pb, Pt, Ir, C
Metals or alloy films of u, Au, etc .; ITO (indium tin oxide), ATO (antimony tin oxide), FTO (fluorine tin oxide), FATO (fluorine antimony tin oxide), AZO (aluminum zinc oxide) , PZT (lead zinc titanium oxide), RuO ₂ , MgF ₂ , CaF ₂ ,
A metal oxide film such as SrF ₂ or BaF ₂ ; or a resin film such as polyimide or acryl can be formed, and the thickness thereof is not particularly limited.
It is set to about 10 μm.

The substrates are Si substrate, Ge substrate, MgO substrate, LiNbO ₃ substrate, GaAs substrate, I substrate.
An nP substrate, a GaN substrate, a Vycor glass substrate, a silica glass substrate or the like can be used.

After forming the first film 2, a hydrolyzable metal compound, a photosensitizer which releases water by irradiation with actinic rays (hereinafter referred to as "water generating agent"), and further, if necessary. A composition (hereinafter, referred to as “mask pattern forming agent”) containing a photosensitizer (hereinafter, referred to as “acid generator”) that liberates acid upon irradiation with actinic rays is applied on the first film 2. , Figure 1
As shown in (b), a photosensitive coating film (second film) 3 is formed.

As the hydrolyzable metal compound contained in the mask pattern forming agent, the general formula A can be obtained by baking the coating film.
Hydrolyzable organometallic compounds or metal halides capable of forming metal oxides represented by BO ₃ are preferred.

A is Y, Sr, Ba, Ca, Mg,
One or more selected from the group consisting of Pb, Sn, Al, Ta and Li, and B is Y, Zr, Ti, N
One or more selected from the group consisting of b, Ta, Sb and Al.

Specific examples of the metal oxide represented by ABO ₃ and other metal oxides suitable for the present invention include PbZ.
rTiO ₃ , SrTiO ₃ , BaTiO ₃ , BaSrT
iO ₃ , LiNbO ₃ , TiO ₂ , Al ₂ O ₃ , ZrO
₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , Y ₂ O ₃ , SnO ₂ , Z
nO, Sn (Sb) O ₂ (Sb / Sn = 0.1 to 15)
%), Zn (Al) O (Al / Zn = 0.1-15%)
Etc.

The hydrolyzable organometallic compound which forms such a metal oxide is not particularly limited as long as it can form a hydroxide of the above metal by hydrolysis, but its typical example is Can include metal alkoxides, metal acetylacetonate complexes, and metal 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, fluoride or the like can be used.

These hydrolyzable metal compounds may be used alone or in combination of two or more in a predetermined ratio depending on the metal element composition of the metal oxide produced.

As the water generating agent for generating water for hydrolyzing the hydrolyzable metal compound, o-nitrobenzyl alcohol, 1-hydroxymethyl-2-nitronaphthalene, 2-nitroethanol, formaldehyde,
One or more selected from the group consisting of tartaric acid, 2-hydroxybenzyl alcohol, 2-carboxybenzyl alcohol, 2-carboxybenzaldehyde, 2-nitrobenzaldehyde and phthalic acid are exemplified.

This water-generating agent is irradiated with actinic rays and undergoes a dehydration reaction to generate water.

In 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, an acid-generating agent which releases an acid upon irradiation with actinic rays is used in combination. May be. 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, those conventionally known in the field of photoresist 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; and also o- or p-nitrobenzyl. Examples thereof include esters, benzene polysulfonates, bisarylsulfonyldiazomethanes, aromatic sulfonates such as 2-phenylsulfonylacetophenone, and sulfonyl compounds.

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

The mask pattern forming agent used in the present invention is
After dissolving the raw material hydrolyzable metal compound in a suitable organic solvent (eg, alcohols such as ethanol, isopropanol, 2-methoxyethanol, n-butanol; lower aliphatic carboxylic acids such as acetic acid and propionic acid), It can be prepared by adding a water generating agent (or a water generating agent and an acid generating agent) to the obtained solution and dissolving them.

In the present invention, the concentration of the hydrolyzable metal compound in the mask pattern forming agent is preferably within the range of 1 to 20% by weight in terms of the metal oxide produced. The concentration of the water generator is 0.001 to 20% by weight, particularly 0.1 to 10% by weight, and the concentration of the acid generator is 20% by weight or less, especially 0.001 to 20% by weight, and especially It is within the range of 0.1 to 10% by weight. In this case, the total concentration of the water generator and the acid generator is preferably 20% by weight or less.

If the amount of the water-generating agent added is too small, the difference in solubility between the exposed area and the unexposed area 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.

In the mask pattern forming agent, a chelate-forming compound such as acetylacetone, ethanolamine or ethyl oxobutanoate is used as a stabilizer for preventing gelation during storage with respect to 1 mol of the hydrolyzable metal compound. You may add in the ratio of 0.05-10 mol.

The coating of the mask pattern forming agent on the first film 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 industrially adopted. Often. If necessary, the coating operation can be repeated after the coating film has gelated to obtain a desired coating film thickness. Since the mask pattern forming agent according to the present invention can be irradiated with a small amount of energy by adding a water-generating agent, the coating film can be thickened.

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 a desired mask 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. The image-forming exposure can be carried out by irradiating an actinic ray through a mask by a conventional method, or by a direct writing method of irradiating a patterned laser beam when the actinic ray source is a laser. The irradiation energy amount is not particularly limited and varies depending on the film thickness and the type of the photosensitizer, but is usually 100 mJ / cm ² or more.

By the irradiation of this actinic radiation, 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 coexists, 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 irradiation with the actinic rays,
40 to 10 in a dry inert gas (N ₂ , Ar, etc.) atmosphere
You may leave at 0 degreeC for about 1 to 10 minutes. 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 carried out 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 first film. The solvent used as the developer may be any solvent that can dissolve the material in the unexposed area and has low solubility in the cured film in the exposed area. Generally, it is preferred to use 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. Thus, it is not necessary to use a corrosive acid such as a hydrofluoric acid / hydrochloric acid mixed acid for development.
It is one of the great advantages of the present invention that development can be carried out in a solvent such as alcohol which is not corrosive and is safe and inexpensive.

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 first film 2 of the substrate 1. afterwards,
When the substrate 1 is heat-treated to completely convert the metal compound in the coating film into the metal oxide, the desired metal oxide thin film mask pattern 3A is obtained. This heat treatment is usually preferably carried out by firing at 300 to 800 ° C. for 1 second to 2 hours in the atmosphere or oxygen atmosphere.
Is preferably about 0.01 to 1.0 μm in thickness after this heat treatment.

After the mask pattern 3A is formed in this manner, dry etching is performed in accordance with a conventional method, and the portion of the first film 2 which is not protected by the mask pattern 3A is etched.
Is etched.

In this dry etching, a microwave plasma etching apparatus or the like is used and the pressure is 1 to 200 mTorr.
r, RF power (1 to 200 MHz) 0.1 to 1000
It can be performed under the condition of about W. Further, as the etching gas, HF, CF ₄ , HCl, HBr, Br ₂ ,
BCl ₃ , Cl ₂ , CCl ₂ F ₂ , SF ₆ , BF ₃ , S
A halogen-based gas such as iF ₄ , C ₃ F ₈ or the like can be used. Specifically, the above-mentioned gas and Ar, O ₂ , NO ₂ , N _{2 can be used.}
It is often used as a mixed gas such as, and those having the following compositions are preferably used.

BCl ₃ / Cl ₂ / HBr, CCl ₂ F ₂
/ O ₂ / HBr, CF ₄ / O ₂ / HBr, SF ₆ , SF
₆ / HBr, Ar / Cl ₂ / O ₂ , CF ₄ / H ₂ , CC
l ₄ / Cl ₂ As a result, the first film 2 is etched according to the mask pattern 3A made of the second film, and the target pattern 2A derived from the first film 2 remains on the substrate 1.

Although the mask pattern 3A is removed as necessary, it may be used without removing the mask pattern 3A. Further, the mask pattern 3A may be removed by a dry etching process.

The method according to claim 3 can be carried out in the same manner as the method according to claim 1, except that the mask pattern forming agent is applied directly to the substrate 1 without forming the first film.

That is, first, as shown in FIG. 2A, a coating film (photosensitive film) 3 is similarly formed on the substrate 1 by using the mask pattern forming agent according to the above-mentioned method, and similarly. Exposure and development are performed to form a mask pattern 3A.

Then, by dry etching according to the above-described method, the substrate 1 is etched according to the mask pattern 3A, and the surface of the substrate 1 is etched to form the concave portion 1A of the target pattern.

The etching depth of the substrate 1 is appropriately determined according to the purpose of use of the substrate, but in the normal case, it is 0.
It is set to about 1 to 50 μm.

Also in the method of the third aspect, the mask pattern 3A is removed as necessary, but it can be used without removing it.

[0053]

The hydrolyzable metal compound in the mask pattern forming agent according to the present invention is hydrolyzed by reacting with water, and is gelled through the sol of hydrous metal oxide. When the reaction further proceeds, the metal-oxygen bond is formed. As a result, a three-dimensional cross-linking polymerization reaction occurs and the film is cured. This mask pattern forming agent contains a water-generating agent that liberates water upon irradiation with actinic rays, and water is generated from this water-generating agent upon irradiation with actinic rays to accelerate the hydrolysis reaction of the hydrolyzable metal compound. To be done. Therefore, in the exposed area, the curing reaction of the film obtained by applying the mask pattern forming agent remarkably progresses, and the difference in solubility between the exposed area and the unexposed area becomes very large.

After exposing the coating film of this mask pattern forming agent to form an image, the unexposed portion is removed by bringing it into contact with a solvent. Then, by heat treatment, the product of the exposed portion remains as a mask pattern.

When the mask pattern forming agent 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.

[0056]

EXAMPLES The present invention will be described in more detail with reference to the following examples.

Example 1 An Al--Cu alloy film was patterned according to the method shown in FIG.

First, Al-C having a film thickness of 5 μm is formed on a Si substrate.
A u alloy film is vapor-deposited (FIG. 1A), and a mask pattern forming agent having the composition shown in Table 1 is applied onto this Al—Cu alloy film by spin coating at 3000 rpm for 15 seconds to form a coating film. Was formed (FIG. 1 (b)).

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. The irradiation dose is 90
0 mJ / cm ² and the mask used has a line width of 10 μm
It was a line and space photomask. After the ultraviolet irradiation, the substrate was heated and dried at 100 ° C. for 1 minute in the air atmosphere. Next, for development, the substrate was immersed in an etching solution (2-methoxyethanol) at room temperature for 1 minute to 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. Then, it is baked in an air atmosphere at 400 ° C. for 5 minutes, and further in an air atmosphere at 500 ° C. for 10 minutes to form Al-
A mask pattern made of a TiO ₂ film having a thickness of 0.05 μm was obtained on the Cu alloy film (FIG. 1 (c)).

Next, this substrate was placed in a chamber for microwave plasma etching, and anisotropic etching was performed. As the etching gas, the following mixed composition was used, the chamber pressure was 1.0 to 3.0 Pa, and the magnetic field was 150 G.
auss, RF power (13.56 MHz) 800 W.

Etching gas composition (sccm) BCl ₃ : 8 Cl ₂ : 15 HBr: 15 As a result, as shown in FIG. 1D, a substrate obtained by etching the Al—Cu alloy film into a target pattern shape can be obtained. It was

Example 2 In Example 1, the MgO substrate was used as the substrate, and the first
A PZT film (thickness: 0.5 μm) was formed as the film of No. 2, and the same process was performed except that the mask pattern forming agent having the composition shown in Table 1 was used as the second film. A mask pattern made of a BaSrTiO ₃ film having a film thickness of 0.01 μm was formed.

Next, this substrate was placed in a chamber for microwave plasma etching, and anisotropic etching was performed. An etching gas having the following mixed composition was used, the chamber pressure was 100 mTorr, and the magnetic field was 100 Ga.
Uss and RF power (13.56 MHz) 800W.

Etching gas composition (sccm) CCl ₂ F ₂ : 8 O ₂ : 5 HBr: 15 As a result, as shown in FIG. 1D, a substrate in which the PZT film was etched into a target pattern shape could be obtained. .

Example 3 In Example 1, a polyimide film (thickness: 2 μm) was formed as the first film, and a mask pattern forming agent having the composition shown in Table 1 was used as the second film. Except for the above, the procedure is the same as above, except that a 0.01 μm thick Al ₂ film is formed on the polyimide film.
A mask pattern made of an O ₃ film was formed.

Next, this substrate was placed in a chamber for microwave plasma etching, and the chamber was 200 mT in pressure with an etching gas having the same composition as that used in Example 1.
orr, magnetic field 150 Gauss, RF power (13.5
Anisotropic etching was performed under the conditions of 6 MHz) and 100 W.

As a result, as shown in FIG. 1D, it was possible to obtain a substrate in which the polyimide film was etched into a target pattern shape.

Example 4 In Example 1, a Vycor glass substrate was used as the substrate, an ITO film (thickness 0.3 μm) was formed as the first film, and a mask having the composition shown in Table 1 was formed as the second film. The same procedure is performed except that the film is formed using the pattern forming agent, and I
Sn (Sb) O ₂ (Sb with a thickness of 0.01 μm is formed on the TO film.
/Sn=2.8%) to form a mask pattern.

Next, this substrate was placed in a chamber for microwave plasma etching, and the chamber pressure was 100 mT with the etching gas having the same composition as that used in Example 2.
orr, magnetic field 150 Gauss, RF power (13.5
Anisotropic etching was performed under the conditions of 6 MHz and 600 W.

As a result, as shown in FIG.
A substrate in which the O film was etched into a target pattern shape could be obtained.

Example 5 In Example 1, a RuO ₂ film (thickness: 0.2 μm) was formed as the first film, and a mask pattern forming agent having the composition shown in Table 1 was used as the second film. The same procedure was performed except that the film was formed, and a PbZ film having a thickness of 0.01 μm was formed on the RuO ₂ film.
A mask pattern made of the rTiO ₃ film was formed.

Next, this substrate was placed in a chamber for microwave plasma etching, and the etching gas having the following composition was used, the chamber pressure was 100 mTorr, and the magnetic field was 150 G.
The anisotropic etching was performed under the conditions of aus and RF power (13.56 MHz) of 150 W.

Etching gas composition (sccm) CF ₄ : 10 O ₂ : 5 HBr: 15 As a result, as shown in FIG. 1D, a substrate in which the RuO ₂ film was etched into a target pattern shape could be obtained.

Example 6 A substrate was patterned according to the method shown in FIG.

First, in Example 1, exposure and development were performed in the same manner as in Example 1 except that the mask pattern forming agent having the composition shown in Table 1 was directly applied without forming the first film. A mask pattern made of a SrTiO ₃ film having a film thickness of 0.01 μm was formed.

Next, this substrate was set for a chamber for microwave plasma etching, and SF ₆ : 2 sccm was set.
Etching gas, chamber pressure 50μbar, magnetic field 1
Anisotropic etching was performed under the conditions of 00 Gauss and RF power density of 0.5 W / cm ² .

As a result, as shown in FIG. 2C, it was possible to obtain a Si substrate (etching depth: 2 μm) that was etched into a target pattern shape.

Example 7 The same procedure as in Example 6 was carried out except that a CaAs substrate was used as the substrate and the mask pattern forming agent having the composition shown in Table 1 was used, and a BaSr film having a thickness of 0.02 μm was formed on the substrate.
A mask pattern made of a TiO ₃ film was formed.

Next, this substrate was placed in a chamber for microwave plasma etching, and an etching gas having the following composition was used, the chamber pressure was 1.0 to 3.0 Pa, and the magnetic field was 150.
Gauss, RF power (13.56MHz) 600W
Anisotropic etching was performed under the above conditions.

Etching gas composition (sccm) Ar: 8 Cl ₂ : 15 O ₂ : 5 As a result, as shown in FIG. 2D, the CaAs substrate (etching depth 2.3) was etched into a target pattern shape.
μm) could be obtained.

Example 8 A mask pattern made of a Ta ₂ O ₅ film having a film thickness of 0.01 μm was formed on a substrate in the same manner as in Example 6 except that the mask pattern forming agent having the composition shown in Table 1 was used. Was formed.

Next, this substrate was placed in a chamber for microwave plasma etching, and anisotropic etching was performed in the same manner as in Example 6.

As a result, as shown in FIG. 2D, it was possible to obtain a Si substrate (etching depth: 3 μm) that was etched into a target pattern shape.

Example 9 In Example 6, an InP substrate was used as the substrate and Table 1
The same procedure was performed except that the mask pattern forming agent having the composition shown in FIG.
_A mask pattern consisting of _three films was formed.

Next, this substrate was placed in a chamber for microwave plasma etching, and anisotropic etching was performed in the same manner as in Example 1.

As a result, as shown in FIG. 2D, it was possible to obtain an InP substrate (etching depth: 2 μm) that was etched into a target pattern shape.

[0087]

[Table 1]

[0088]

As described in detail above, according to the patterning methods of the first and third aspects, a mask pattern made of a metal oxide can be easily and accurately formed without using an organic resist. Therefore, according to the present invention, the patterning process by dry etching is greatly simplified, and the patterning cost and the patterning efficiency are significantly improved.

According to the patterning methods of the second and fourth aspects, more efficient patterning can be performed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a method of an embodiment of a patterning method of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment method of the patterning method of the present invention.

FIG. 3 is a cross-sectional view showing a conventional patterning method.

FIG. 4 is a cross-sectional view showing a conventional patterning method.

[Explanation of symbols]

 1 Substrate 1A Recess 2 First Film 2A Target Pattern 3 Second Film (Photosensitive Film) 3A Mask Pattern

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication H01L 21/3065 H05K 3/28 C (72) Inventor Tsutomu Atsugi 1-297 Kitabukuro-cho, Omiya-shi, Saitama Address Mitsubishi Materials Corp. Central Research Laboratory (72) Inventor Katsumi Ogi 1-297 Kitabukuro-cho, Omiya City, Saitama Prefecture Mitsubishi Materials Corp. Central Research Laboratory

Claims (4)

[Claims] 1. A first film is formed on a substrate, a photosensitive second film is formed, the second film is formed into a predetermined mask pattern, and a dry etching process is performed to form the second film. In the patterning method, wherein the first film is etched according to the mask pattern to leave a target pattern derived from the first film on the substrate, the second film is composed of at least a hydrolyzable metal compound,
When the second film is patterned by forming a composition containing a photosensitizer that releases water upon irradiation with actinic radiation on the first film, the second film is formed by patterning the second film. Image-wise exposing with actinic rays, developing with a solvent to remove the unexposed area, and then heat-treating to convert the film in the exposed area into metal oxide, thereby forming the mask pattern made of metal oxide. And a patterning method. 2. The patterning method according to claim 1, wherein the composition further contains a photosensitizer that liberates an acid upon irradiation with actinic radiation. 3. A photosensitive film is formed on a substrate, the photosensitive film is formed into a predetermined mask pattern, and then the surface of the substrate is etched according to the mask pattern by dry etching to form a mask on the surface of the substrate. In a patterning method for forming concave portions of a target pattern, the photosensitive film, at least a hydrolyzable metal compound,
When the photosensitive film is patterned by forming a composition containing a photosensitizer which releases water upon irradiation with actinic rays on the substrate, the photosensitive film is imaged with the actinic rays. After exposing and developing with a solvent to remove the unexposed portion, heat treatment is performed to convert the film in the exposed portion into metal oxide, thereby forming the mask pattern made of metal oxide. Method. 4. The patterning method according to claim 3, wherein the composition further contains a photosensitizer that liberates an acid upon irradiation with actinic radiation.