JPH11258803A - Pattern forming material and pattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a positive surface decorating process instead of a negative surface decorating process. SOLUTION: The pattern forming material consists of a polymer containing groups which produce acids by irradiation of energy beams or heating, and a compd. which produces a base by irradiation of energy beams. The polymer is binary or more-component polymer produced by polymerizing a compd. expressed by the formula with other groups. In the formula, R1 is a hydrogen atom or alkyl group, R2 and R3 are each independently hydrogen atoms, alkyl groups, phenyl groups or alkenyl groups, or bonded to form a cyclic structure of a cyclic alkyl group, cyclic alkenyl group, cyclic alkyl group having a phenyl group or a cyclic alkenyl group having a phenyl group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method of forming a fine resist pattern in a process of manufacturing a semiconductor integrated circuit device and the like, and a pattern forming material used in the method.

[0002]

2. Description of the Related Art Hitherto, in the manufacture of ICs or LSIs, patterns have been formed by photolithography using ultraviolet rays, but with the miniaturization of semiconductor elements, the use of short-wavelength light sources has been promoted. In the case where a short-wavelength light source is used, development of a surface resolution process using dry development has been advanced in recent years in order to increase the depth of focus and improve the practical resolution.

As a surface resolution process, for example, US Pat.
As shown in P5,278,029, after a polysiloxane film is selectively formed on the surface of a resist film made of a resist that generates an acid when exposed, the polysiloxane is used as a mask to form a resist on the resist film. A negative type surface modification process for forming a resist pattern by performing dry etching by using a conventional method has been proposed.

Hereinafter, a method of forming the resist pattern will be described with reference to FIGS.

As a resist which generates an acid when exposed, a copolymer of 1,2,3,4-tetrahydronaphthylideneimino-p-styrenesulfonate (NISS) and methyl methacrylate (MMA) is used. An example will be described.

First, as shown in FIG. 9A, an ArF excimer laser 14 is irradiated using a mask 13 on a resist film 11 applied on a semiconductor substrate 10 and generating an acid when exposed. Then, acid is generated in the exposed portion 11a of the resist film 11. Due to the action of the acid, the exposed portion 11a changes to hydrophilicity and easily adsorbs water in the atmosphere. Therefore, as shown in FIG. 9B, a thin water adsorbing layer 15 is formed near the surface of the exposed portion 11a. Is formed.

Next, when an alkoxysilane gas 16 is introduced into the surface of the resist film 11, the acid generated on the surface of the exposed portion 11a acts as a catalyst to cause hydrolysis and dehydration condensation of the alkoxysilane, and FIG. As shown in c), a metal oxide film 17 is formed on the surface of the exposed portion 11a. Thereafter, when dry etching is performed on the resist film 11 by RIE using O ₂ plasma 18 using the metal oxide film 17 as a mask, a fine resist pattern 19 is formed as shown in FIG. It is.

[0008]

However, according to the above-described pattern forming method, an acid is generated in an exposed portion of a resist film, and a metal oxide film is selectively formed in the exposed portion using the generated acid as a catalyst. Since a resist pattern is formed by performing dry etching using the metal oxide film as a mask, a negative lithography process is performed in which a resist pattern is formed on an exposed portion of the resist film.

The negative type lithography process has the following problems, for example, when forming a contact hole for connecting a multilayer wiring of an integrated circuit.

First, as described below, there is a problem in using a mask usually used for pattern exposure. In the lithography step of forming a contact hole, when a negative lithography process is used as described above, the aperture ratio of the mask becomes very high. That is, on the mask, a light-shielding film for exposure light is formed only in the contact hole portion, while the light-shielding film is removed in portions other than the contact hole in order to transmit the exposure light, and the quartz of the mask substrate is exposed. Become. In general, the ratio of the area occupied by all contact holes to the area of the semiconductor chip is very small, so that the ratio of the exposed quartz area to the area of the light-shielding film in the mask is high, that is, the aperture ratio of the mask is high.

As the aperture ratio of the mask increases, the influence of dust contamination from the environment increases. That is, even if dust adheres to the light-shielding film portion of the mask, there is almost no effect. However, if dust adheres to the transparent portion of the mask, the portion where the dust adheres becomes a light-shielding portion. When exposure is performed using a mask to which dust is attached, a pattern defect occurs in a portion corresponding to the dust attached portion. As described above, the negative lithography process has a high aperture ratio of the mask,
There is a problem that it is susceptible to dust and the yield is easily reduced.

Next, the second problem will be described. In a lithography process for forming a contact hole, a halftone type mask may be used for the purpose of improving the depth of focus. There is a problem that can not be. For this reason, when forming a contact hole, there is a problem that a negative type process has a smaller depth of focus than a positive type process.

The above-mentioned first and second problems occur not only when forming a contact hole but also when using a mask having a large light transmitting portion and when improving the depth of focus.

In view of the above, an object of the present invention is to realize a positive surface modification process instead of a negative surface modification process.

[0015]

In order to achieve the above object, the present invention provides a polymer containing a group that generates an acid by heating or irradiation with a first energy beam; Forming a resist film comprising a compound that generates a base by irradiation with a second energy beam different from the first energy beam. In an exposed portion of the resist film subjected to pattern exposure, an acid generated from the polymer and a base generated from the compound are exposed to light. On the other hand, the acid generated from the polymer is left in the unexposed portion of the resist film which has not been subjected to pattern exposure, and the metal alkoxide is reacted by the catalytic action of the remaining acid to form a metal oxide film.

The first pattern forming material according to the present invention comprises:
It comprises a polymer containing a group that generates an acid when heated, and a compound that generates a base when irradiated with an energy beam.

When the resist film formed of the first pattern forming material is heated, an acid is generated from the polymer over the entire surface. After that, when the resist film is pattern-exposed by an energy beam, the resist film is exposed. In the part, the base is generated from the compound, and the acid generated from the polymer and the base generated from the compound are neutralized, while the acid remains in the unexposed part of the resist film.

The second pattern forming material according to the present invention comprises:
A polymer containing a group that generates an acid when irradiated with a first energy beam in a first energy band, and a polymer that includes a second energy beam in a second energy band different from the first energy band. And a compound that generates a base.

When the entire surface of the resist film formed by the second pattern forming material is exposed by the first energy beam, an acid is generated from the polymer over the entire surface, and the resist film is subjected to pattern exposure by the second energy beam. Then, in the exposed portion of the second energy beam in the resist film, a base is generated from the compound, while the acid generated from the polymer and the base generated from the compound are neutralized,
An acid remains in a portion of the resist film that has not been exposed to the second energy beam.

In the first or second pattern forming material, the polymer has a general formula

[0021]

Embedded image

(However, R ₁ represents a hydrogen atom or an alkyl group, and R ₂ and R ₃ are each independently a hydrogen atom, an alkyl group, a phenyl group or an alkenyl group, or both are cyclic. A cyclic alkyl group, a cyclic alkenyl group, a cyclic alkyl group having a phenyl group, or a cyclic alkenyl group having a phenyl group). preferable.

Here, the proportion of the compound represented by the general formula [Chemical Formula 5] in the binary polymer is arbitrary, but may be 50 mol% or less in order to facilitate neutralization with a base. It may be desirable.

Further, in the first pattern forming material,
The polymer has the general formula

[0025]

Embedded image

(Wherein, R ₁ represents a hydrogen atom or an alkyl group, and R ₄ represents an alkyl group, an alkenyl group, a cyclic alkyl group or a cyclic alkenyl group). The polymer is preferably a binary or higher polymer.

The compound represented by the general formula [Chemical Formula 6] has a feature that almost no acid is generated by light irradiation (energy beam irradiation). Where 2
The proportion of the compound represented by the general formula [Chemical Formula 6] in the original polymer or more is arbitrary, but may be desirably 50 mol% or less in order to facilitate neutralization with a base.

In the first or second pattern forming material, the compound is preferably an acyloxime, a benzyloxycarbonyl compound or formamide.

The first pattern forming method according to the present invention comprises:
A first step of forming a resist film by applying a pattern forming material comprising a polymer containing a group that generates an acid when heated and a compound that generates a base when irradiated with an energy beam onto a semiconductor substrate And a second step of heating the resist film to generate an acid from the polymer, and irradiating the resist film with an energy beam through a mask having a desired pattern shape, thereby forming a base from the compound on the exposed portion of the resist film. A third step of neutralizing the acid generated from the polymer and the base generated from the compound in the exposed portion of the resist film by supplying a metal alkoxide to the resist film, A fourth step of forming a metal oxide film on the surface of the portion, and performing dry etching on the resist film using the metal oxide film as a mask; And a fifth step of forming the door pattern.

According to the first pattern forming method, when the resist film is heated, an acid is generated from the polymer over the entire surface of the resist film. In the exposed portion of the film, a base is generated from the compound, and the acid generated from the polymer and the base generated from the compound are neutralized, while the acid remains in the unexposed portion of the resist film. Next, when a metal alkoxide is supplied to the resist film, the metal alkoxide reacts in the unexposed portion of the resist film due to the catalytic action of the remaining acid to form a metal oxide film, while in the exposed portion of the resist film, Since the metal oxide film is neutralized, no metal oxide film is formed.

A second pattern forming method according to the present invention comprises:
A first step of forming a resist film by applying a pattern forming material comprising a polymer containing a group that generates an acid when heated and a compound that generates a base when irradiated with an energy beam onto a semiconductor substrate And a second step of irradiating the resist film with an energy beam through a mask having a desired pattern shape to generate a base from a compound in an exposed portion of the resist film, and heating the resist film to remove an acid from the polymer. Generating a third step of neutralizing the base generated from the compound and the acid generated from the polymer in the exposed portion of the resist film, and supplying a metal alkoxide to the resist film to form an unexposed portion of the resist film. A fourth step of forming a metal oxide film on the surface of the substrate, and performing dry etching on the resist film using the metal oxide film as a mask to form a resist film comprising the resist film. A fifth step of forming a pattern.

According to the second pattern forming method, when the resist film is subjected to pattern exposure by the energy beam,
A base is generated from the compound in the exposed portion of the resist film,
Thereafter, when the resist film is heated, an acid is generated from the polymer over the entire surface of the resist film, and in the exposed portion of the resist film, the base generated from the compound and the acid generated from the polymer are neutralized. On the other hand, acid remains in the unexposed portions of the resist film. Next, when a metal alkoxide is supplied to the resist film, the metal alkoxide reacts in the unexposed portion of the resist film due to the catalytic action of the remaining acid to form a metal oxide film, while in the exposed portion of the resist film, Since the metal oxide film is neutralized, no metal oxide film is formed.

In the first or second pattern forming method, it is preferable that the fourth step includes a step of absorbing water in an unexposed portion of the resist film.

A third pattern forming method according to the present invention comprises:
A compound that generates a base when irradiated with a first energy beam in a first energy band, and generates an acid when irradiated with a second energy beam in a second energy band different from the first energy band A first step of forming a resist film by applying a pattern forming material comprising a polymer onto a semiconductor substrate, and irradiating the resist film with a first energy beam through a mask having a desired pattern shape; A second step of generating a base from a compound in a portion of the resist film exposed to the first energy beam, and irradiating the entire surface of the resist film with a second energy beam to apply an acid from a polymer to the entire surface of the resist film; By generating the acid, the base generated from the compound and the acid generated from the polymer are neutralized in the first energy beam exposed portion of the resist film. A third step of supplying a metal alkoxide to the resist film to form a metal oxide film on the surface of the resist film where the first energy beam has not been exposed, and a resist using the metal oxide film as a mask. A fifth step of performing dry etching on the film to form a resist pattern made of a resist film.

According to the third pattern forming method, when the resist film is subjected to pattern exposure by the first energy beam, a base is generated from the compound in the exposed portion of the resist film at the first energy beam, and thereafter, the resist film is exposed. Is exposed from the entire surface by the second energy beam, an acid is generated from the polymer. In the first energy beam exposed portion of the resist film, the base generated from the compound and the acid generated from the polymer are neutralized, while the acid remains in the unexposed first energy beam portion of the resist film. I do. Next, when a metal alkoxide is supplied to the resist film, the metal alkoxide reacts in the unexposed portion of the first energy beam of the resist film due to the catalytic action of the remaining acid to form a metal oxide film. In the exposed portion of the film with the first energy beam, the metal oxide film is not formed because it is neutralized.

In the third pattern forming method, the fourth step preferably includes a step of absorbing water in the unexposed portion of the resist film with the first energy beam.

A fourth pattern forming method according to the present invention comprises:
A polymer that generates an acid when irradiated with a first energy beam in a first energy band, and generates a base when irradiated with a second energy beam in a second energy band different from the first energy band A first step of forming a resist film by applying a pattern-forming material comprising a compound to be formed on a semiconductor substrate, and irradiating the entire surface of the resist film with a first energy beam to form a resist film from a polymer. A second step of generating an acid, and irradiating the resist film with a second energy beam through a mask having a desired pattern shape, so that the exposed portion of the second energy beam in the resist film is converted from a compound to a base. Is generated to neutralize the acid generated from the polymer and the base generated from the compound in the exposed portion of the resist film with the second energy beam. A third step of supplying a metal alkoxide to the resist film to form a metal oxide film on a surface of the resist film where the second energy beam has not been exposed, and using the metal oxide film as a mask. A fifth step of performing dry etching on the resist film to form a resist pattern made of the resist film.

According to the fourth pattern forming method, when the resist film is entirely exposed by the first energy beam, an acid is generated from the polymer over the entire surface of the resist film,
Thereafter, when the resist film is subjected to pattern exposure with the second energy beam, a base is generated from the compound in the exposed portion of the resist film with the second energy beam, and an acid generated from the polymer and a base generated from the compound are generated. Is neutralized, while an acid remains in a portion of the resist film that is not exposed to the second energy beam. Next, when a metal alkoxide is supplied to the resist film, the unexposed portion of the second energy beam in the resist film is
The metal alkoxide reacts due to the catalytic action of the remaining acid to form a metal oxide film. On the other hand, the metal oxide film is not formed in the exposed portion of the resist film exposed to the second energy beam because it is neutralized.

In the fourth pattern forming method, the fourth step preferably includes a step of absorbing water in the unexposed portion of the resist film with the second energy beam.

In the first to fourth pattern forming methods,
The polymer has the general formula

[0041]

Embedded image

(However, R ₁ represents a hydrogen atom or an alkyl group, and R ₂ and R ₃ are each independently a hydrogen atom, an alkyl group, a phenyl group or an alkenyl group, or both are cyclic. A cyclic alkyl group, a cyclic alkenyl group, or a cyclic alkyl group having a phenyl group or a cyclic alkenyl group).

Here, the proportion of the compound represented by the general formula [Chemical Formula 7] in the binary polymer is arbitrary, but may be 50 mol% or less in order to facilitate neutralization with a base. It may be desirable.

Further, in the first or second pattern forming method, the polymer is represented by the general formula

[0045]

Embedded image

(Wherein R ₁ represents a hydrogen atom or an alkyl group, and R ₄ represents an alkyl group, an alkenyl group, a cyclic alkyl group or a cyclic alkenyl group). The polymer is preferably a binary or higher polymer.

The compound represented by the general formula [Chemical Formula 8] has a feature that almost no acid is generated by light irradiation (energy beam irradiation). Where 2
The proportion of the compound represented by the general formula [Chemical Formula 8] in the original polymer is arbitrary, but may be desirably 50 mol% or less in order to facilitate neutralization with a base.

In the first to fourth pattern forming methods, the compound is preferably an acyl oxime, a benzyloxy carbonyl compound or formamide.
In particular, examples of the acyl oxime include o-phenylacetyl-aceto-α-naphthone-oxime, o-phenylacetyl-aceto-β-naphtone-oxime, o-phenylacetyl-acetophenone-oxime, and the like.

According to a fifth pattern forming method of the present invention,
A first step of forming a resist film by applying a pattern forming material comprising a polymer containing a group that generates an acid when heated and a compound that generates a base when irradiated with an energy beam onto a semiconductor substrate And a second step of heating the resist film to generate an acid from the polymer, irradiating the resist film with an energy beam through a mask having a desired pattern shape, and then subjecting the resist film to pattern exposure. Performing a water treatment on the film in a gas phase or a liquid phase to generate a base from the compound in an exposed portion of the resist film, and neutralizing the generated base and an acid in the resist film; By exposing the film to a mixed gas atmosphere of water vapor and a metal alkoxide after exposing the film to a water vapor atmosphere, a metal oxide film is formed on the surface of the unexposed portion of the resist film. A step, by performing dry etching of the metal oxide film as a mask the resist film, and a fifth step of forming a resist pattern made of the resist film.

A sixth pattern forming method according to the present invention comprises:
A first step of forming a resist film by applying a pattern forming material comprising a polymer containing a group that generates an acid when heated and a compound that generates a base when irradiated with an energy beam onto a semiconductor substrate And a second step of heating the resist film to generate an acid from the polymer, irradiating the resist film with an energy beam through a mask having a desired pattern shape, and then subjecting the resist film to pattern exposure. By keeping the film under an atmosphere of an inert gas, a base is generated from the compound in the exposed portion of the resist film, and the third step is to neutralize the generated base and the acid of the resist film.
And a fourth step of exposing the resist film to an atmosphere of water vapor and then exposing the resist film to a mixed gas atmosphere of water vapor and metal alkoxide to form a metal oxide film on the surface of the unexposed portion of the resist film. A fifth step of performing dry etching on the resist film using the metal oxide film as a mask to form a resist pattern made of the resist film.

According to a seventh pattern forming method of the present invention,
A first step of forming a resist film by applying a pattern forming material comprising a polymer containing a group that generates an acid when heated and a compound that generates a base when irradiated with an energy beam onto a semiconductor substrate And a second step of heating the resist film to generate an acid from the polymer, irradiating the resist film with an energy beam through a mask having a desired pattern shape, and then subjecting the resist film to pattern exposure. A third step of exposing the film to an atmosphere of water vapor under an atmosphere of an inert gas to generate a base from the compound in an exposed portion of the resist film, thereby neutralizing the generated base and an acid of the resist film; Forming a metal oxide film on the surface of the unexposed portion of the resist film by exposing the resist film to a mixed gas atmosphere of water vapor and a metal alkoxide; A metal oxide film as a mask dry etching is performed, and a fifth step of forming a resist pattern made of the resist film against.

[0052]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS.
(D) is sectional drawing which shows each process of the pattern formation method which concerns on 1st Embodiment of this invention.

As the resist material, a copolymer represented by the following formula [9] (a polymer containing a group capable of generating an acid upon heating) and a compound represented by the following formula [10] (an energy beam (ArF excimer laser)) are used. A mixture of a compound (a compound that generates a base upon irradiation) dissolved in diglyme.

[0054]

Embedded image

[0055]

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First, as shown in FIG. 1A, a resist material having a thickness of 1 μm was spin-coated on a semiconductor substrate 100 made of silicon and pre-baked at a temperature of 90 ° C. for 90 seconds. A film 101 is formed. At this time, no peeling of the film occurred, and the resist film 101 having good adhesion was obtained. Further, as shown in [Chemical formula 11], sulfonic acid was generated from the copolymer represented by [Chemical formula 9] due to the heat of the prebaking.

[0057]

Embedded image

Next, a mask 1 is applied to the resist film 101.
The resist film 101 is irradiated with an ArF excimer laser 104 as an energy beam using
Then, the pattern of the mask 103 is transferred. As a result, o-phenylacetyl-acetophenone-oxime is decomposed on the surface of the exposed portion 101a of the resist film 101 as shown in the chemical reaction formula [Chem. 12] to generate benzylamine.

[0059]

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The unexposed portion 101b of the resist film 101
It exhibits strong acidity due to the function of the sulfonic acid group in the chemical formula shown in [Chemical formula 11]. On the other hand, the exposed portion 10 of the resist film 101
In 1a, as shown in the chemical reaction formula [Chemical formula 12], o-phenylacetyl-acetophenone-oxime is decomposed to generate basic benzylamine, and the benzylamine functions as a sulfonic acid group. Neutralize to some extent to counteract acidity due to

The unexposed portion 101b of the resist film 101
Exposure part 101a neutralized to show strong acidic polarity
In this state, water is easily adsorbed. That is, in the unexposed portion 101b, a strong acidic polarity group is present, and the hydrogen bond with water is strengthened, so that water is easily absorbed. On the other hand, in the exposed portion 101a, the hydrogen bond with water is weakened by the neutralization, so that the water is hardly absorbed.

Next, as shown in FIG. 1B, the semiconductor substrate 100 is kept in air at a relative humidity of 95% at a temperature of 30 ° C. for 30 minutes to form a resist film 101.
Is supplied to the surface of the substrate. This way,
Water vapor 105 is adsorbed on the surface of the unexposed portion 101b where water is easily adsorbed, and water is diffused from the surface of the unexposed portion 101b to a deep portion, for example, a portion of 100 nm. Since the exposed portion 101a is neutralized, water is hardly adsorbed, and the water adsorbing layer 106 is selectively formed on the unexposed portion 101b.

Next, as shown in FIG. 1C, while the semiconductor substrate 100 is held in air at a relative humidity of 95% at a temperature of 30 ° C., methyltriethoxysilane (MTEOS) as a metal alkoxide is used. Is sprayed onto the surface of the resist film 101 for 30 minutes, so that the metal oxide film 10
8 are selectively formed. In this case, an acid (H ⁺ ) from sulfonic acid acts as a catalyst to cause a reaction between MTEOS hydrolysis and dehydration condensation to form a metal oxide film 108. The metal oxide film 108 grows where an acid (H ⁺ ) as a catalyst and water are present.

According to the first embodiment, the resist film 10
In the first exposed portion 101a, the sulfonic acid is neutralized by the generation of benzylamine to lose its function as a catalyst, and it is difficult for water to be absorbed, so that no metal oxide film is formed. On the other hand, the unexposed portion 101b of the resist film 101
In the above, the metal oxide film 108 is formed because H ⁺ of the catalyst is present and a sufficient amount of water is absorbed.

Next, as shown in FIG. 1 (d), by using the O ₂ plasma 109 and the metal oxide film 108 as a mask R
By performing IE (Reactive Ion Etching)
A resist pattern 110 is formed. In this case, the O ₂ plasma RIE condition is, for example, a parallel plate type RIE.
Using the device, power: 900W, pressure: 0.7Pa,
Flow rate: 40 SCCM.

According to the first embodiment, the unexposed portion 101
Since the metal oxide film 108 is selectively formed only on the portion b, and etching is performed using the metal oxide film 108, the unexposed portion 10
A 0.15 μm positive resist pattern 110 having a cross section perpendicular to 1b can be formed.

In the step shown in FIG. 1B, since water vapor 105 is supplied to the resist film 101, water is diffused from the surface of the unexposed portion 101b of the resist film 101 to a deep portion. Since the growth of the film 108 proceeds inside the resist film 101, the metal oxide film 108 having a large thickness can be formed.

Further, in the step shown in FIG.
Since MTEOS is supplied to the resist film 101 in air at a relative humidity of 95%, evaporation of the water absorbed by the resist film 101 is prevented, and the metal oxide film 10 is removed.
Since the water necessary for forming the layer 8 is supplied and the equilibrium state of the water is maintained, the metal oxide film 108 having a sufficient thickness to withstand RIE of O ₂ plasma can be formed.

As described above, according to the first embodiment, the resist film 101 in which an acid is generated from the copolymer by heating is subjected to pattern exposure, and the exposed portion 101a generates a base to expose the resist film 101. While neutralizing the acidity of the portion 101a, the metal oxide film 108 is selectively formed only on the unexposed portion 101b, and then the resist film 101 is etched using the metal oxide film 108 as a mask. And a fine positive resist pattern 110 can be formed.

Since the unexposed portion 101b is forcibly absorbing water before the growth of the metal oxide film 108, the metal oxide film 108 having a sufficient film thickness necessary for dry development by O ₂ plasma RIE is formed. can do.

As the metal alkoxide, MTEOS was used, but instead of CH ₃ Si (OCH ₃ )
₃ (methyltrimethoxysilane), Si (OCH ₃ ) _{4
(Tetramethoxysilane), Si (OC 2 H5)} 4 ( _{tetraethoxysilane), Ti (OC 2 H 5} ) 4, Ge
(OC ₂ H ₅ ) ₄ , Al (OC ₂ H ₅ ) ₃ or Zr (O
Other metal alkoxides such as C ₂ H ₅ ) ₃ may be supplied in the gas or liquid phase.

Although RIE using O ₂ plasma is used as a method for dry development, ECR (Electron Cyclotron Resonance Etching) using O ₂ plasma may be used instead. Further, as an etching gas type, SO ₂ gas or the like may be added to O ₂ gas.

Although an ArF excimer laser is used as an exposure light source, an i-line, a KrF excimer laser, VUV, EUV, EB, X-ray, or the like may be used instead.

Further, the unexposed portion 10 of the resist film 101
In the step of diffusing water to the surface of 1b, the semiconductor substrate 100 is held in water vapor. Alternatively, liquid water may be supplied to the resist film 101 on the semiconductor substrate 100. However, it is preferable to supply gas-phase water rather than liquid-phase water, because the diffusion of water proceeds quickly and the depth of the metal oxide film 108 increases.

(Second Embodiment) FIGS. 2A to 2D
FIGS. 4A to 4C are cross-sectional views illustrating each step of a pattern forming method according to a second embodiment of the present invention. FIGS.

As a resist material, a copolymer represented by the following formula [Chemical Formula 13] (a polymer containing a group generating an acid upon heating) and a compound represented by the following Formula [Chemical Formula 14] (energy beam (ArF excimer laser)) are used. A mixture of a compound (a compound that generates a base upon irradiation) dissolved in diglyme.

[0077]

Embedded image

[0078]

Embedded image

First, as shown in FIG. 2A, the resist material is spin-coated on a semiconductor substrate 200 made of silicon, and pre-baked at a temperature of 120 ° C. for 90 seconds to form a film having a thickness of 1 μm. Is formed. At this time, no peeling of the film occurred, and the resist film 201 having good adhesion was obtained. Further, as shown in [Chemical Formula 15], sulfonic acid was generated from the copolymer represented by [Chemical Formula 13] due to the heat of the prebaking.

[0080]

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Next, mask 2 is applied to resist film 201.
The resist film 201 is irradiated with an ArF excimer laser 204 as an energy beam using
Is transferred to the mask 203. As a result, o-phenylacetyl-acetophenone-oxime is decomposed on the surface of the exposed portion 201a of the resist film 201, as shown in the chemical reaction formula [Chem. 16], to generate benzylamine.

[0082]

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The unexposed portion 201b of the resist film 201
It exhibits strong acidity due to the function of the sulfonic acid group in the chemical formula shown in [Formula 15]. On the other hand, the exposed portion 20 of the resist film 201
In 1a, o-phenylacetyl-acetophenone-oxime is decomposed to generate basic benzylamine as shown in the chemical reaction formula [Formula 16], and the benzylamine functions as a sulfonic acid group. Neutralize to some extent to counteract acidity due to

The unexposed portion 201b of the resist film 201
Exposure portion 201a neutralized to show strong acidic polarity
In this state, water is easily adsorbed. That is, in the unexposed portion 201b, since a group having strong acidic polarity is present, the hydrogen bond with water is strengthened, so that water is easily absorbed. On the other hand, in the exposure unit 201a, the hydrogen bond with water is weakened by the neutralization, so that the water is hardly absorbed.

Next, as shown in FIG. 2B, the semiconductor substrate 200 is kept in air at a relative humidity of 95% at a temperature of 30 ° C. for 30 minutes to form a resist film 201.
Water vapor 205 is supplied to the surface of. This way,
Water vapor 205 is adsorbed on the surface of the unexposed portion 201b where water is easily adsorbed, and water is diffused from the surface of the unexposed portion 201b to a deep portion, for example, a portion of 100 nm. Since the exposed portion 201a is neutralized, water is hardly adsorbed, and the water adsorbing layer 206 is selectively formed on the unexposed portion 201b.

Next, as shown in FIG. 2C, while the semiconductor substrate 200 is held in air at a relative humidity of 95% at a temperature of 30 ° C., methyltrimethoxysilane (MTMOS) as a metal alkoxide is used. Is sprayed onto the surface of the resist film 201 for 20 minutes, so that the metal oxide film 20
8 are selectively formed. In this case, an acid (H ⁺ ) from sulfonic acid acts as a catalyst to cause a reaction between hydrolysis and dehydration condensation of MTMOS to form a metal oxide film 208. The metal oxide film 208 grows where an acid (H ⁺ ) as a catalyst and water are present.

According to the second embodiment, the resist film 20
In the first exposed portion 201a, the sulfonic acid is neutralized by the generation of benzylamine and loses its function as a catalyst, and water is hardly absorbed, so that no metal oxide film is formed. On the other hand, the unexposed portion 201b of the resist film 201
In the above, the metal oxide film 208 is formed because H ⁺ of the catalyst is present and a sufficient amount of water is absorbed.

[0088] Next, as shown in FIG. 2 (d), with O ₂ plasma 209 and the metal oxide film 208 as a mask R
By performing IE (Reactive Ion Etching)
A resist pattern 210 is formed. In this case, the O ₂ plasma RIE condition is, for example, a parallel plate type RIE.
Using the device, power: 900W, pressure: 0.7Pa,
Flow rate: 40 SCCM.

According to the second embodiment, the unexposed portion 201
Since the metal oxide film 208 is selectively formed only on the portion b, and etching is performed using the metal oxide film 208, the unexposed portion 20
A 0.15 μm positive resist pattern 210 having a cross section perpendicular to 1b can be formed.

In the step shown in FIG. 2B, since water vapor 205 is supplied to the resist film 201, water is diffused from the surface of the unexposed portion 201b of the resist film 201 to a deep portion. Since the growth of the film 208 proceeds inside the resist film 201, the metal oxide film 208 having a large thickness can be formed.

Further, in the step shown in FIG.
Since MTMOS is supplied to the resist film 201 in air at a relative humidity of 95%, evaporation of water absorbed by the resist film 201 is prevented and the metal oxide film 20 is prevented from being evaporated.
Since the water necessary for forming the layer 8 is supplied and the equilibrium state of the water is maintained, the metal oxide film 208 having a sufficient thickness to withstand RIE of O ₂ plasma can be formed.

As described above, according to the second embodiment, the resist film 201 in which an acid is generated from the copolymer by heating is subjected to pattern exposure, and the exposed portion 201a generates a base to expose the resist film 201. While the acidity of the portion 201a is neutralized, the metal oxide film 208 is selectively formed only on the unexposed portion 201b, and thereafter, the resist film 201 is etched using the metal oxide film 208 as a mask. And a fine positive resist pattern 210 can be formed.

In order to forcibly absorb water in the unexposed portion 201b before the growth of the metal oxide film 208, the metal oxide film 208 having a sufficient film thickness required for dry development by RIE of O ₂ plasma is formed. can do.

As the metal alkoxide, MTMOS was used. Instead, CH ₃ Si (OC ₂ H ₅ ) _{3 was used.}
(Methyltriethoxysilane), Si (OCH ₃ ) ₄
(Tetramethoxysilane), Si (OC ₂ H ₅ ) ₄ (tetraethoxysilane), Ti (OC ₂ H ₅ ) ₄ , Ge
(OC ₂ H ₅ ) ₄ , Al (OC ₂ H ₅ ) ₃ or Zr (O
Other metal alkoxides such as C ₂ H ₅ ) ₃ may be supplied in the gas or liquid phase.

Although RIE using O ₂ plasma is used as a method of dry development, ECR (Electron Cyclotron Resonance Etching) using O ₂ plasma may be used instead. Further, as an etching gas type, SO ₂ gas or the like may be added to O ₂ gas.

Although an ArF excimer laser is used as an exposure light source, an i-line, a KrF excimer laser, VUV, EUV, EB, X-ray, or the like may be used instead.

Further, the unexposed portion 20 of the resist film 201
In the step of diffusing water to the surface of 1b, the semiconductor substrate 200 is held in water vapor. Alternatively, liquid water may be supplied to the resist film 201 on the semiconductor substrate 200. However, it is preferable to supply gas-phase water rather than liquid-phase water, because the diffusion of water proceeds quickly and the depth of the metal oxide film 208 increases.

(Third Embodiment) FIGS. 2A to 2D
FIGS. 9A and 9B are also cross-sectional views illustrating respective steps of a pattern forming method according to a third embodiment of the present invention.

As a resist material, a copolymer represented by the following formula [Chemical Formula 17] (a polymer containing a group generating an acid upon heating) and a compound represented by the following Formula [Chemical Formula 18] (energy beam (ArF excimer laser)) are used. A mixture comprising a compound (a compound that generates a base upon irradiation) dissolved in monoglyme is used.

[0100]

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[0101]

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First, as shown in FIG. 2A, the resist material is spin-coated on a semiconductor substrate 200 made of silicon, and pre-baked at a temperature of 80 ° C. for 90 seconds to form a resist having a thickness of 1 μm. A film 201 is formed.
At this time, no peeling of the film occurred, and the resist film 201 having good adhesion was obtained. In this pre-bake,
No acid was generated from the copolymer represented by the formula [7].

Next, a mask 2 is applied to the resist film 201.
The resist film 201 is irradiated with an ArF excimer laser 204 as an energy beam using
Is transferred to the mask 203. By doing so, o-phenylacetyl-acetonaphthone-oxime is decomposed on the surface of the exposed portion 201a of the resist film 201 to generate benzylamine.

Next, the resist film 201 is heated at 120 ° C.
Baking at a temperature of 90 seconds. Due to the heat of the baking, sulfonic acid was generated from the copolymer represented by Chemical Formula 17, as shown in the chemical reaction formula of Chemical Formula 19.

[0105]

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The unexposed portion 201b of the resist film 201
It exhibits strong acidity due to the function of the sulfonic acid group in the chemical formula shown in [Chemical Formula 19]. On the other hand, the exposed portion 20 of the resist film 201
In 1a, since o-phenylacetyl-acetonaphthone-oxime is decomposed to generate basic benzylamine, the benzylamine counteracts the acidity caused by the action of the sulfonic acid group, and is thus neutralized to some extent.

The unexposed portion 201b of the resist film 201
Exposure portion 201a neutralized to show strong acidic polarity
In this state, water is easily adsorbed. That is, in the unexposed portion 201b, since a group having strong acidic polarity is present, the hydrogen bond with water is strengthened, so that water is easily absorbed. On the other hand, in the exposure unit 201a, the hydrogen bond with water is weakened by the neutralization, so that the water is hardly absorbed.

Next, as shown in FIG. 2B, the semiconductor substrate 200 is kept in air at a temperature of 30 ° C. and a relative humidity of 95% for 30 minutes to form a resist film 201.
Water vapor 205 is supplied to the surface of. This way,
Water vapor 205 is adsorbed on the surface of the unexposed portion 201b where water is easily adsorbed, and water is diffused from the surface of the unexposed portion 201b to a deep portion, for example, a portion of 100 nm. Since the exposed portion 201a is neutralized, water is hardly adsorbed, and the water adsorbing layer 206 is selectively formed on the unexposed portion 201b.

Next, as shown in FIG. 2C, with the semiconductor substrate 200 held in air at a relative humidity of 95% at a temperature of 30 ° C., methyltrimethoxysilane (MTMOS) as a metal alkoxide is used. Is sprayed onto the surface of the resist film 201 for 20 minutes, so that the metal oxide film 20
8 are selectively formed. In this case, an acid (H ⁺ ) from sulfonic acid acts as a catalyst to cause a reaction between hydrolysis and dehydration condensation of MTMOS to form a metal oxide film 208. The metal oxide film 208 grows where an acid (H ⁺ ) as a catalyst and water are present.

According to the third embodiment, the resist film 20
In the first exposed portion 201a, the sulfonic acid is neutralized by the generation of benzylamine and loses its function as a catalyst, and water is hardly absorbed, so that no metal oxide film is formed. On the other hand, the unexposed portion 201b of the resist film 201
In the above, the metal oxide film 208 is formed because H ⁺ of the catalyst is present and a sufficient amount of water is absorbed.

[0111] Next, as shown in FIG. 2 (d), with O ₂ plasma 209 and the metal oxide film 208 as a mask R
By performing IE (Reactive Ion Etching)
A resist pattern 210 is formed. In this case, the O ₂ plasma RIE condition is, for example, a parallel plate type RIE.
Using the device, power: 900W, pressure: 0.7Pa,
Flow rate: 40 SCCM.

According to the third embodiment, the unexposed portion 201
Since the metal oxide film 208 is selectively formed only on the portion b, and etching is performed using the metal oxide film 208, the unexposed portion 20
A 0.15 μm positive resist pattern 210 having a cross section perpendicular to 1b can be formed.

Further, in the step shown in FIG. 2B, since water vapor 205 is supplied to the resist film 201, since water is diffused from the surface of the unexposed portion 201b of the resist film 201 to a deep portion, metal oxide is formed. Since the growth of the film 208 proceeds inside the resist film 201, the metal oxide film 208 having a large thickness can be formed.

Further, in the step shown in FIG.
Since MTMOS is supplied to the resist film 201 in air at a relative humidity of 95%, evaporation of water absorbed by the resist film 201 is prevented and the metal oxide film 20 is prevented from being evaporated.
Since the water necessary for forming the layer 8 is supplied and the equilibrium state of the water is maintained, the metal oxide film 208 having a sufficient thickness to withstand RIE of O ₂ plasma can be formed.

As described above, according to the third embodiment, after the resist film 201 is subjected to pattern exposure to generate a base in the exposed portion 201a, an acid is generated from the copolymer by heating to expose the base. While neutralizing the basicity of the portion 201a, the metal oxide film 208 is selectively formed only on the unexposed portion 201b, and then the resist film 201 is etched using the metal oxide film 208 as a mask. An excellent and fine positive resist pattern 210 can be formed.

Since the unexposed portion 201b is forcibly absorbing water before the growth of the metal oxide film 208, the metal oxide film 208 having a sufficient film thickness necessary for dry development by O ₂ plasma RIE is formed. can do.

As the metal alkoxide, MTMOS was used. Instead, CH ₃ Si (OC ₂ H ₅ ) _{3 was used.}
(Methyltriethoxysilane), Si (OCH ₃ ) ₄
(Tetramethoxysilane), Si (OC ₂ H ₅ ) ₄ (tetraethoxysilane), Ti (OC ₂ H ₅ ) ₄ , Ge
(OC ₂ H ₅ ) ₄ , Al (OC ₂ H ₅ ) ₃ or Zr (O
Other metal alkoxides such as C ₂ H ₅ ) ₃ may be supplied in the gas or liquid phase.

As the dry development method, RIE using O ₂ plasma is used, but ECR (Electron Cyclotron Resonance Etching) using O ₂ plasma may be used instead. Further, as an etching gas type, SO ₂ gas or the like may be added to O ₂ gas.

Although an ArF excimer laser is used as an exposure light source, an i-line, a KrF excimer laser, VUV, EUV, EB or X-ray may be used instead.

Further, the unexposed portion 20 of the resist film 201
In the step of diffusing water to the surface of 1b, the semiconductor substrate 200 is held in water vapor. Alternatively, liquid water may be supplied to the resist film 201 on the semiconductor substrate 200. However, it is preferable to supply gas-phase water rather than liquid-phase water, because the diffusion of water proceeds quickly and the depth of the metal oxide film 208 increases.

(Fourth Embodiment) FIGS. 3A to 3C and FIGS. 4A and 4B are cross-sectional views showing steps of a pattern forming method according to a third embodiment of the present invention. FIG.

Examples of the resist material include a copolymer represented by the following chemical formula (a polymer containing a group that generates an acid by irradiation with a second energy beam (i-line));
(A compound that generates a base by irradiation with a first energy beam (ArF excimer laser))
Is dissolved in diglyme and a mixture is used.

[0123]

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[0124]

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First, as shown in FIG. 3A, the resist material is spin-coated on a semiconductor substrate 300 made of silicon, and heated at a temperature of 90 ° C. for 90 seconds to form a resist having a thickness of 1 μm. A film 301 is formed. At this time, no peeling of the film occurred, and a resist film 301 having good adhesion was obtained.

Next, mask 3 is applied to resist film 301.
The pattern of the mask 303 is transferred to the resist film 301 by irradiating an ArF excimer laser 304 as a first energy beam using the light-emitting element 03. As a result, o-tert-butylacetyl-acetophenone-oxime is decomposed on the surface of the exposed portion 301a of the resist film 301 as shown in the chemical reaction formula [Chem. 22] to generate amine.

[0127]

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Next, as shown in FIG. 3B, a resist film 3 is formed by using an i-ray 305 as a second energy beam.
01 is entirely exposed. By doing so, Ar
In the exposed portion 301a that has been pattern-exposed by the F excimer laser 304, as shown in the chemical reaction formula [Chem. 12], the entire surface is exposed to the i-ray 305, so that acidic sulfonic acid is generated.

[0129]

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On the other hand, in the unexposed portion 301b where the pattern exposure by the ArF excimer laser 304 was not performed, as shown in the chemical reaction formula [Chemical Formula 23], the i-line 3
Since the sulfonic acid is generated by the whole surface exposure by the method of No. 05, it shows acidity. At this time, since the unexposed portion 301b has a strong acidic polarity, water is more likely to be adsorbed than the neutralized exposed portion 301a.

Next, as shown in FIG. 3C, the resist film 301 is held by keeping the semiconductor substrate 300 in air at a temperature of 30 ° C. and a relative humidity of 95% for 30 minutes.
Water vapor 307 is supplied to the surface of. This way,
Water vapor 307 is adsorbed on the surface of the unexposed portion 301b where water is easily adsorbed, and water is diffused from the surface of the unexposed portion 301b to a deep portion, for example, a portion of 100 nm. Since the exposed portion 301a is neutralized, water is hardly adsorbed, and a water adsorption layer 308 is selectively formed on the unexposed portion 301b.

Next, as shown in FIG. 4A, with the semiconductor substrate 300 held in air at a temperature of 30 ° C. and a relative humidity of 95%, MT
When the EOS vapor 309 is sprayed on the surface of the resist film 301 for 30 minutes, the unexposed portion 301b of the resist film 301 is exposed.
Metal oxide film 310 is selectively formed on the surface of. In this case, the acid (H ⁺ ) from the sulfonic acid acts as a catalyst to produce MT
A reaction between hydrolysis and dehydration condensation of EOS occurs, and a metal oxide film 310 is formed. The metal oxide film 310 grows where an acid (H ⁺ ) as a catalyst and water are present.

According to the fourth embodiment, the resist film 30
In the first exposed portion 301a, the function of the amine is neutralized by the generation of sulfonic acid to lose the function as a catalyst, and it is difficult for water to be absorbed. Therefore, no metal oxide film is formed. On the other hand, in the unexposed portion 301b of the resist film 301, a metal oxide film 310 is formed because a catalyst acid is present and a sufficient amount of water is absorbed.

[0134] Next, as shown in FIG. 4 (b), by using the O ₂ plasma 311 and the metal oxide film 310 as a mask R
By performing IE, a resist pattern 312 is formed. In this case, the RIE conditions of the O ₂ plasma are set, for example, by using a parallel plate type RIE apparatus with a power of 900.
W, pressure: 0.7 Pa, flow rate: 40 SCCM.

According to the fourth embodiment, the unexposed portion 301
b, a metal oxide film 310 is selectively formed only on the unexposed portion 30 because the metal oxide film 310 is etched using the metal oxide film 310.
A 0.15 μm positive resist pattern 312 having a cross section perpendicular to 1b can be formed.

In the process shown in FIG. 3C, since water vapor 307 is supplied to the resist film 301, water is diffused from the surface of the unexposed portion 301b of the resist film 301 to a deep portion. Since the growth of the metal oxide film 310 proceeds inside the resist film 301, the metal oxide film 310 having a large thickness can be formed. In particular, since the acid is generated only on the surface portion of the resist film 301, the thickness of the water adsorption layer 308 can be limited to the depth at which the acid is generated. Can be prevented from wrapping around.

Further, in the step shown in FIG.
Since MTEOS is supplied to the resist film 301 in air at a relative humidity of 95%, evaporation of water absorbed by the resist film 301 is prevented and the metal oxide film 31 is removed.
Since the water necessary for forming 0 is supplied and the equilibrium state of water is maintained, the metal oxide film 310 having a sufficient thickness to withstand RIE of O ₂ plasma can be formed.

As described above, according to the fourth embodiment, after pattern exposure is performed using the first energy beam to generate a base in the exposed portion 301a, the entire surface is formed using the second energy beam. Exposure is performed to generate an acid, so that the exposed portion 301 is pattern-exposed.
While neutralizing a, the unexposed portion 301b is made acidic to selectively form the metal oxide film 310 only on the unexposed portion 301b, and then the resist film 3 is formed using the metal oxide film 310.
Since the etching is performed on 01, a fine positive type resist pattern 312 having a good shape can be formed. In addition, since the unexposed portion 301b is forcibly absorbing water before the growth of the metal oxide film 310, the metal oxide film 310 having a sufficient film thickness required for dry development by RIE of O ₂ plasma may be formed. it can.

Incidentally, in the fourth embodiment, MTEOS was used as the metal alkoxide, but CH ₃ Si (OCH ₃ ) ₃ (methyltrimethoxysilane), Si (OCH ₃ ) ₄ was used instead. _{(tetramethoxysilane), Si (OC 2 H 5} ) 4 ( _{tetraethoxysilane), Ti (OC 2 H 5} ) 4, Ge (OC 2 H 5) 4,
Other metal alkoxides such as Al (OC ₂ H ₅ ) ₃ or Zr (OC ₂ H ₅ ) ₃ may be used in the gas or liquid phase.

As the method of dry development, RIE using O ₂ plasma is used, but ECR (Electron Cyclotron Resonance Etching) using O ₂ plasma may be used instead. Further, as an etching gas type, SO ₂ gas or the like may be added to O ₂ gas.

The unexposed portion 301 of the resist film 301
b) in the step of diffusing water to the surface of the semiconductor substrate 3
Although 00 is held in water vapor, liquid water may be supplied to the resist film 301 on the semiconductor substrate 300 instead. However, it is preferable to supply gas-phase water rather than liquid-phase water, because the diffusion of water proceeds quickly and the depth of the metal oxide film 310 increases.

(Modification of Fourth Embodiment) A polymer containing a group capable of generating an acid by a first energy beam (for example, i-ray) (a copolymer represented by Chemical Formula 20) and a second
Energy beam (eg, ArF excimer laser)
A mixture with a compound that generates a base (compound represented by Chemical Formula 21) is used as a resist material.

After the entire surface of the resist film is exposed to the first energy beam to generate an acid from the copolymer,
Pattern exposure is performed by the second energy beam to generate a base in the exposed portion of the resist film exposed to the second energy beam. By doing so, in the exposed portion of the resist film with the second energy beam, the acid generated from the copolymer and the base generated from the compound are neutralized.

On the other hand, in the unexposed portion of the resist film where the second energy beam has not been exposed, the acid generated from the copolymer remains. After supplying water vapor to absorb the water, the water vapor and the alkoxysilane are separated. When supplied, a metal oxide film is formed.

Next, a resist pattern is formed by etching the resist film using the metal oxide film.

According to the modification of the fourth embodiment,
As in the first to fourth embodiments, a fine positive resist pattern having a good shape can be formed.

In the first embodiment, the second embodiment, the third embodiment, the fourth embodiment and the modifications thereof, as the polymer, [Chemical Formula 9], [Chemical Formula 13], [Chemical Formula 13] Chemical 1
7] and [Chemical Formula 20], but instead of this, for example, a copolymer containing a group that generates a sulfonic acid, such as those represented by Chemical Formulas 24 to 30 A combination may be used, and a polymer containing a group having a strong acid property may be used instead of the group that generates sulfonic acid.

[0148]

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[0149]

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[0150]

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[0151]

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[0152]

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[0153]

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[0154]

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The proportion of the group generating sulfonic acid or the group having the property of a strong acid in the copolymer is not limited, but is preferably 50 mol% or less in order to facilitate neutralization with a base. Sometimes it is desirable.

In the first embodiment, the second embodiment,
In the third embodiment, the fourth embodiment and modifications thereof, the compound that generates a base includes, for example, [Chemical Formula 3]
Compounds containing a group that generates an amine as shown in [1] to [Formula 36] may be used, or a compound that generates a group having basic properties may be used instead of the group that generates an amine. it can.

[0157]

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[0158]

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[0159]

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[0160]

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[0161]

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[0162]

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Further, the first embodiment, the second embodiment,
In the third embodiment, the fourth embodiment and the modifications thereof, a polymer containing a sulfonic acid-generating group was used. However, instead of this, the group shown in [Formula 37] may be used as the sulfonic acid-generating group. A binary polymer obtained by polymerization may be used.

[0164]

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In the fourth embodiment, an ArF excimer laser is used as an exposure light source in pattern exposure using a first energy beam. Instead, an i-ray, a KrF excimer laser, an EB or an X-ray is used. Etc. may be used. In this case, it is necessary to use a compound that generates a base by irradiation with these energy beams, instead of the compound represented by Chemical Formula 21. Although the i-line is used as the exposure light source in the overall exposure using the second energy beam, another light source may be used.
Also in this case, instead of the polymer represented by [Chemical Formula 20],
It is necessary to use a polymer containing a group that generates an acid by irradiation with another light source.

In the first to fourth embodiments, the selectivity of the metal oxide film as the surface modification film is not sufficient, and the residue formed of the metal oxide film remains on the semiconductor substrate after forming the resist pattern. There is a problem that occurs.

Therefore, in the first embodiment, the mechanism by which o-phenylacetyl-acetophenone-oxime was decomposed to generate benzylamine when the surface of the resist film was subjected to pattern exposure with an energy beam was examined. The mechanism by which o-phenylacetyl-acetophenone-oxime is decomposed to generate benzylamine is as shown in [Formula 38].

[0168]

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First, when light is irradiated, o-phenylacetyl-acetophenone-oxime undergoes a first reaction, that is, radical decomposition, and is decomposed into radicals a, CO ₂ , and radicals b. After that, a second reaction occurs, and the radical a and the radical b are combined, and then the third reaction, that is, hydrolysis by moisture in the air occurs, and benzylamine is generated.

By the way, the present inventor repeated experiments by increasing the amount of exposure to ArF excimer laser light in order to increase the amount of base (OH ⁻ ) generated in the unexposed portions of the resist film and reduce residues. As a result, a residue was formed on the semiconductor substrate.

Further, when the chemical reaction shown in [Chemical Formula 38] was carried out in various environments, it was found that the amount of benzylamine produced differs depending on the environment in which the chemical reaction is carried out. The reaction No. 2 was found to be inhibited by the influence of impurities such as carbon present in the atmosphere. That is, the third reaction in the chemical reaction formula shown in [Chemical Formula 38], that is, hydrolysis by atmospheric moisture is necessary, but at this time, the second reaction is inhibited by impurities such as carbon present in the atmosphere. Because

A method for reducing the residue of the metal oxide film generated on the semiconductor substrate after forming the resist pattern will be described below.

(Fifth Embodiment) Hereinafter, a pattern forming method according to a fifth embodiment of the present invention will be described with reference to FIG.
6 (a) to 6 (c) and FIGS. 6 (a) to 6 (c).

First, as shown in FIG. 5A, a resist material having the following composition was applied on a semiconductor substrate 400 to form a resist film 401 having a thickness of 0.5 μm.

Polymer: poly (propylidene iminostyrene sulfonic acid (14 mol%)-co-methyl methacrylic acid (86 mol%)) 10 g Base generating compound: o-phenylacetylacetophenone oxime 2.3 g Solvent: diglyme 40 g Next, the resist film 401 is heated 402 by a hot plate at a temperature of 90 ° C. for 60 seconds, and acid (H) is applied over the entire surface of the resist film 401 as shown in FIG. ⁺ ).

Next, as shown in FIG. 5C, using a mask 403 having a desired pattern shape, an ArF excimer laser beam 404 (NA: 0.55) is used to perform exposure at an exposure energy of 250 mJ / cm ² . Perform FIG.
In (c), 401a indicates an exposed portion, and 401b indicates an unexposed portion.

Next, as shown in FIG. 6A, a steam process for supplying steam 406 over the entire surface of the resist film 401 is performed in an atmosphere of N ₂ gas 405. In this case, the reaction is not hindered by impurities in the atmosphere, and therefore, in the exposed portion 401a of the resist film 401, a base (O) composed of benzylamine from o-phenylacetylacetophenone oxime, which is a base generating compound,
H ⁻ ) is sufficiently formed, and the fully formed base (OH
^- ) Neutralizes the acid (H ⁺ ) in the resist film 401 almost completely.

Next, as shown in FIG. 6B, a steam process for supplying steam 406 and a CVD process for supplying methyltrimethoxysilane 407 are performed over the entire surface of the resist film 401. By doing so, the resist film 4
The polysiloxane film 408 as a metal oxide film is formed only in the unexposed portion 401b of No. 01.

Next, as shown in FIG. 6C, the resist film 401 is developed by performing dry etching with an O ₂ gas 409 using the polysiloxane film 408 as a mask to form a resist pattern 410. . By doing so, no residue is formed in the exposed portion 401a of the resist film 401.

According to the fifth embodiment, N ₂ gas 405
In the above atmosphere, the steam treatment for supplying the steam 406 over the entire surface of the resist film 401 is performed, so that the second reaction in the chemical reaction formula shown in [Chem. Since the third reaction in the formula is promoted, the generation efficiency of the base from the base generating compound is improved.

(Sixth Embodiment) Hereinafter, a pattern forming method according to a sixth embodiment of the present invention will be described with reference to FIG.
6C, FIGS. 6B and 6C, and FIGS. 7A and 7B.
This will be described with reference to FIG.

First, as shown in FIG. 5A, a resist material having the same composition as in the fourth embodiment is applied on a semiconductor substrate 400 to form a resist film 401.
At a temperature of 90 ° C. with respect to the resist film 401,
By performing heating 402 using a hot plate for 60 seconds, acid (H ⁺ ) is generated over the entire surface of the resist film 401 as shown in FIG. 5B, and thereafter, as shown in FIG. 5C. Mask 403 having a desired pattern shape
Exposure is performed using ArF excimer laser light 404 by using.

Next, as shown in FIG. 7A, moisture 420 is supplied in a gas phase or a liquid phase over the entire surface of the resist film 401. By doing so, the base generating compound ο-
Since phenylacetylacetophenone oxime absorbs a large amount of water, the base (OH ⁻ ) composed of benzylamine is sufficiently generated from o-phenylacetylacetophenone oxime in the exposed portion 401 a of the resist film 401, and the sufficiently generated base is formed. The acid (H ⁺ ) in the resist film 401 is almost completely neutralized by (OH ⁻ ).

Next, as shown in FIG. 7B, after performing a steam process for supplying steam 406 over the entire surface of the resist film 401, as shown in FIG. A steam process for supplying steam 406 and a CVD process for supplying methyltrimethoxysilane 407 are performed over the entire surface. By doing so, the resist film 4
The polysiloxane film 408 as a metal oxide film is formed only in the unexposed portion 401b of No. 01.

Next, as shown in FIG. 6C, the resist film 401 is developed by performing dry etching with an O ₂ gas 409 using the polysiloxane film 408 as a mask to form a resist pattern 410. . By doing so, no residue is formed in the exposed portion 401a of the resist film 401.

According to the sixth embodiment, since the water 420 is supplied to the pattern-exposed resist film 401 in a gas phase or a liquid phase, the third reaction in the chemical reaction formula shown in [Chem.
Is promoted, so that the efficiency of generating a base from the base generating compound is improved.

(Seventh Embodiment) Hereinafter, a pattern forming method according to a seventh embodiment of the present invention will be described with reference to FIG.
6C, FIGS. 6B and 6C, and FIGS. 8A and 8B.
This will be described with reference to FIG.

First, as shown in FIG. 5A, a resist material having the same composition as that of the fourth embodiment is applied on a semiconductor substrate 400 to form a resist film 401.
At a temperature of 90 ° C. with respect to the resist film 401,
By performing heating 402 using a hot plate for 60 seconds, acid (H ⁺ ) is generated over the entire surface of the resist film 401 as shown in FIG. 5B, and thereafter, as shown in FIG. 5C. Mask 403 having a desired pattern shape
Exposure is performed using ArF excimer laser light 404 by using.

Next, as shown in FIG. 8A, the resist film 401 is kept under an atmosphere of N ₂ gas 430. In this case, since the reaction is not hindered by impurities in the atmosphere, the exposed portion 401a of the resist film 401
A base consisting of benzylamine from o-phenylacetylacetophenone oxime, which is a base generating compound (O
H ⁻ ) is sufficiently formed, and the fully formed base (OH
^- ) Neutralizes the acid (H ⁺ ) in the resist film 401 almost completely.

Next, as shown in FIG. 8B, after performing a steam process for supplying steam 406 over the entire surface of the resist film 401, as shown in FIG. A steam process for supplying steam 406 and a CVD process for supplying methyltrimethoxysilane 407 are performed over the entire surface. By doing so, the resist film 4
The polysiloxane film 408 as a metal oxide film is formed only in the unexposed portion 401b of No. 01.

Next, as shown in FIG. 6C, the resist film 401 is developed by performing dry etching with an O ₂ gas 409 using the polysiloxane film 408 as a mask to form a resist pattern 410. . By doing so, no residue is formed in the exposed portion 401a of the resist film 401.

According to the seventh embodiment, since the resist film 401 subjected to the pattern exposure is kept under an atmosphere of N ₂ gas 430, the _second resist in the chemical reaction formula shown in [Chemical Formula 38] is used.
Is not inhibited, so that the efficiency of base generation from the base generating compound is improved.

Incidentally, in the fifth and seventh embodiments,
Although N ₂ gases 405 and 430 were used as the inert gas,
Instead, another inert gas such as Ar gas may be used.

In the fifth to seventh embodiments,
Methyltrimethoxysilane 40 as alkoxysilane
Although 7 was supplied, methyltriethoxysilane, ethyltriethoxysilane or ethyltrimethoxysilane may be used instead. Further, the present invention is not limited to these.

Also, in the fifth to seventh embodiments,
O ₂ was dry-etched by gas as an etching gas species, the O ₂ gas may be added to SO ₂ gas or the like.

[0196] Further, in the fifth to seventh embodiments, an exposure was ArF excimer laser beam, the present invention is not limited thereto. Alternatively, for example, F ₂ such as light VUV Light, EUV light such as 13 nm light, electron beam, X-ray, or the like may be used.

[0197]

According to the first pattern forming material, the acid generated from the polymer and the base generated from the compound are neutralized in the exposed portion of the resist film, while the acid generated in the unexposed portion of the resist film is neutralized. Remains, that is, the acid can be selectively left only in the unexposed portions of the resist film, so that a positive surface modification process can be realized.

According to the second pattern forming material, in the portion of the resist film exposed to the second energy beam, the acid generated from the polymer and the base generated from the compound are neutralized, while the second energy beam in the resist film is neutralized. Since the acid remains in the unexposed part of the energy beam, that is, the acid can be selectively left only in the unexposed part of the second energy beam in the resist film, realizing a positive surface modification process. can do.

Further, since the first or second pattern forming material is a mixture of a polymer containing a group that generates an acid and a compound that generates a base, the flexibility of the mixing ratio between the polymer and the compound is reduced. is there.

In the first or second pattern-forming material, the polymer is a binary polymer or more obtained by polymerizing a compound represented by the general formula [1] with another group, or
In the first pattern forming material, when the polymer is a binary polymer or more obtained by polymerizing another group to a compound represented by the general formula [Chemical Formula 2], metal oxidation occurs in an unexposed portion of the resist film. When forming a film, the sulfonic acid generated from the polymer exerts a strong catalytic action, so that a positive type surface modification process with high contrast can be realized.

In the first or second pattern forming material, when the compound is an acyl oxime, a benzyloxy carbonyl compound or formamide, an amine is generated in the exposed portion of the resist film, and the amine strongly neutralizes the acid. Therefore, a positive type surface modification process with high contrast can be realized.

According to the first pattern forming method, when the resist film is pattern-exposed by an energy beam,
In the exposed part of the resist film, while the acid generated from the polymer and the base generated from the compound are neutralized, while the acid remains in the unexposed part of the resist film, when the metal alkoxide is supplied to the resist film, In the exposed portion of the resist film, the metal oxide film is not formed because it is neutralized. On the other hand, in the unexposed portion of the resist film, the metal oxide film is formed by the catalytic action of the acid. Thereby, a good and fine resist pattern having a positive pattern shape can be formed.

According to the second pattern forming method, when the resist film is heated, the exposed portion of the resist film
While the acid generated from the polymer and the base generated from the compound neutralize, while the acid remains in the unexposed portion of the resist film, when a metal alkoxide is supplied to the resist film, in the exposed portion of the resist film, Since the metal oxide film is not formed due to the neutralization, the metal oxide film is formed by the catalytic action of the acid in the unexposed portion of the resist film. A good and fine resist pattern can be formed.

In the first or second pattern formation method, if the fourth step includes a step of absorbing water into the unexposed portion of the resist film, the water diffuses from the surface to a deep portion in the unexposed portion of the resist film. Therefore, the thickness of the metal oxide film formed on the surface of the unexposed portion of the resist film increases.

According to the third pattern forming method, when the resist film is pattern-exposed by the first energy beam, the exposed portion of the resist film exposed to the first energy beam contains the base generated from the compound and the polymer. While the generated acid neutralizes, the first in the resist film
When the metal alkoxide is supplied to the resist film because the acid remains in the unexposed portion of the energy beam, the metal oxide film is not formed in the exposed portion of the first energy beam in the resist film because the metal alkoxide is neutralized. On the other hand, in the unexposed portion of the first energy beam of the resist film, a metal oxide film is formed by the catalytic action of an acid.
A good and fine resist pattern having a positive pattern shape can be formed.

In the third pattern forming method, if the fourth step includes a step of absorbing water in the unexposed portion of the first energy beam in the resist film, the unexposed portion of the first energy beam in the resist film may be used. In this case, water diffuses from the surface to a deep portion, so that the thickness of the metal oxide film formed on the surface of the resist film where the first energy beam is not exposed is increased.

According to the fourth pattern formation method, when the resist film is subjected to pattern exposure by the second energy beam, the exposed portion of the resist film exposed to the second energy beam is exposed to the acid generated from the polymer and the compound. While the generated base neutralizes, the second in the resist film
When the metal alkoxide is supplied to the resist film because the acid remains in the unexposed portion of the energy beam, the metal oxide film is not formed in the exposed portion of the second energy beam of the resist film because the metal alkoxide is neutralized. On the other hand, the metal oxide film is formed by the catalytic action of the acid in the unexposed portion of the second energy beam in the resist film.
A good and fine resist pattern having a positive pattern shape can be formed.

In the fourth pattern forming method, if the fourth step includes the step of absorbing water in the unexposed portion of the second energy beam in the resist film, the non-exposed portion of the second energy beam in the resist film may be used. In this case, water diffuses from the surface to a deep portion, so that the thickness of the metal oxide film formed on the surface of the resist film where the second energy beam is not exposed becomes large.

In the first to fourth pattern forming methods,
The polymer is a binary polymer or more obtained by polymerizing another group with a compound represented by the general formula [Chemical Formula 3], or
Wherein the polymer has the general formula [Chemical Formula 4]
When the compound represented by is a binary polymer or more obtained by polymerizing another group, when forming a metal oxide film in an unexposed portion of the resist film, sulfonic acid exerts a strong catalytic action, Since a highly selective metal oxide film can be formed only on the unexposed portions of the resist film, a favorable and finer resist pattern having a positive pattern shape can be formed.

In the first to fourth pattern forming methods,
When the compound is an acyl oxime, a benzyloxycarbonyl compound or formamide, an amine is generated in the exposed portion of the resist film, and the amine strongly neutralizes the acid. Since an oxide film can be formed, a favorable and finer resist pattern having a positive pattern shape can be formed.

According to the fifth pattern forming method, after a resist film in which an acid has been generated is subjected to pattern exposure,
In order to perform water treatment in a gas phase or a liquid phase on a resist film subjected to pattern exposure, in an exposed portion of the resist film,
The compound generates a base sufficient to neutralize the acid in the resist film. Therefore, in the exposed portion of the resist film,
Since no metal oxide film is formed because no acid remains, no residue composed of the metal oxide film is formed on the semiconductor substrate after the formation of the resist pattern.

According to the sixth pattern forming method, after a resist film in which an acid has been generated is subjected to pattern exposure,
Since the resist film that has been subjected to the pattern exposure is maintained in an atmosphere of an inert gas, a sufficient amount of base is generated from the compound in the exposed portion of the resist film to neutralize the acid of the resist film. For this reason, in the exposed portion of the resist film, no metal oxide film is formed because no acid remains, so that no residue made of the metal oxide film is formed on the semiconductor substrate after the formation of the resist pattern.

According to the seventh pattern forming method, after a resist film in which an acid is generated is subjected to pattern exposure,
Since the pattern-exposed resist film is exposed to an atmosphere of water vapor under an atmosphere of an inert gas, a sufficient amount of base is generated from the compound in the exposed portion of the resist film to neutralize the acid of the resist film. For this reason, in the exposed portion of the resist film, no metal oxide film is formed because no acid remains, so that no residue made of the metal oxide film is formed on the semiconductor substrate after the formation of the resist pattern.

Further, according to the seventh pattern forming method,
The step of exposing the resist film to the atmosphere of water vapor under an inert gas atmosphere omits the step of exposing the resist film to an atmosphere of water vapor performed before the step of exposing the resist film to an atmosphere of a mixed gas of water vapor and a metal alkoxide. be able to.

Therefore, according to the fifth to seventh pattern forming methods, since a residue made of a metal oxide film is not formed on a semiconductor substrate after a resist pattern has been formed, a cause of a defect caused by the residue in a later step is prevented. Therefore, the yield in the semiconductor manufacturing process can be improved.

[Brief description of the drawings]

FIGS. 1A to 1D are cross-sectional views showing each step of a pattern forming method according to a first embodiment of the present invention.

FIGS. 2A to 2D are cross-sectional views showing each step of a pattern forming method according to a second or third embodiment of the present invention.

FIGS. 3A to 3C are cross-sectional views illustrating respective steps of a pattern forming method according to a fourth embodiment of the present invention.

FIGS. 4A and 4B are cross-sectional views illustrating respective steps of a pattern forming method according to a fourth embodiment of the present invention.

FIGS. 5A to 5C are cross-sectional views illustrating respective steps of a pattern forming method according to a fifth embodiment of the present invention.

FIGS. 6A to 6C are cross-sectional views illustrating respective steps of a pattern forming method according to a fifth embodiment of the present invention.

FIGS. 7A and 7B are cross-sectional views illustrating respective steps of a pattern forming method according to a sixth embodiment of the present invention.

FIGS. 8A and 8B are cross-sectional views illustrating respective steps of a pattern forming method according to a seventh embodiment of the present invention.

FIGS. 9A to 9D are cross-sectional views showing steps of a conventional pattern forming method.

[Explanation of symbols]

100 semiconductor substrate 101 the resist film 101a exposed portion 101b unexposed portion 103 mask 104 ArF excimer laser 105 steam 106 adsorption layer 107 MTEOS steam 108 metal oxide film of water 109 O ₂ plasma 110 resist pattern 200 semiconductor substrate 201 the resist film 201a exposed portion 201b Unexposed portion 203 Mask 204 ArF excimer laser 205 Water vapor 206 Water absorption layer 207 MTMOS vapor 208 Metal oxide film 209 O ₂ plasma 210 Resist pattern 300 Semiconductor substrate 301 Resist film 301a Exposed portion 301b Unexposed portion 303 Mask 304 ArF excimer Laser 305 i-ray 307 Water vapor 308 Water adsorption layer 309 MTEOS vapor 310 Metal oxide film 311 O ₂ plasma 312 Resist Pattern 400 semiconductor substrate 401 resist film 401a exposed part 401b unexposed part 402 heating 403 mask 404 ArF excimer laser 405 atmosphere of N ₂ gas 406 water vapor 407 methyltrimethoxysilane 408 polysiloxane film 409 dry etching of O ₂ gas 410 resist pattern 420 Atmosphere of moisture 430 N ₂ gas

Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03F 7/38 512 G03F 7/38 512 H01L 21/027 H01L 21/30 502R 568 569H

Claims (18)

[Claims] 1. A pattern forming material comprising: a polymer containing a group that generates an acid when heated; and a compound that generates a base when irradiated with an energy beam. 2. A polymer containing a group that generates an acid when irradiated with a first energy beam in a first energy band, and a second energy in a second energy band different from the first energy band. A pattern forming material comprising: a compound that generates a base when irradiated with a beam. 3. The polymer has the general formula: (Provided that R ₁ represents a hydrogen atom or an alkyl group, and R ₂ and R ₃ each represent a hydrogen atom, an alkyl group, a phenyl group or an alkenyl group, each of which is independent of each other, or a cyclic alkyl group formed by both of them; , A cyclic alkenyl group,
3) a compound represented by the formula: (a) represents a cyclic alkyl group having a phenyl group or a cyclic alkenyl group having a phenyl group; 3. The pattern forming material according to item 1. 4. The polymer has a general formula: (However, R ₁ represents a hydrogen atom or an alkyl group, and R ₄ represents an alkyl group, an alkenyl group, a cyclic alkyl group or a cyclic alkenyl group). The pattern forming material according to claim 1, which is a polymer of 5. The pattern forming material according to claim 1, wherein the compound is an acyl oxime, a benzyloxy carbonyl compound, or formamide. 6. A resist film is formed by applying on a semiconductor substrate a pattern forming material comprising a polymer containing a group that generates an acid when heated and a compound that generates a base when irradiated with an energy beam. A first step of heating the resist film to generate an acid from the polymer; and irradiating the resist film with an energy beam through a mask having a desired pattern shape. A third step of generating a base from the compound in the exposed portion of the resist film to neutralize an acid generated from the polymer and a base generated from the compound in the exposed portion of the resist film; Supplying a metal alkoxide to the film to form a metal oxide film on the surface of the unexposed portion of the resist film;
And a fifth step of dry-etching the resist film using the metal oxide film as a mask to form a resist pattern made of the resist film. . 7. A resist film is formed by applying on a semiconductor substrate a pattern forming material comprising a polymer containing a group that generates an acid when heated and a compound that generates a base when irradiated with an energy beam. A first step of irradiating the resist film with an energy beam through a mask having a desired pattern shape to generate a base from the compound in an exposed portion of the resist film; and A third step of neutralizing the base generated from the compound and the acid generated from the polymer in the exposed portion of the resist film by heating the resist film to generate an acid from the polymer; A metal alkoxide to form a metal oxide film on the surface of the unexposed portion of the resist film.
And a fifth step of dry-etching the resist film using the metal oxide film as a mask to form a resist pattern made of the resist film. . 8. The pattern forming method according to claim 6, wherein the fourth step includes a step of absorbing water in an unexposed portion of the resist film. 9. A compound that generates a base when irradiated with a first energy beam in a first energy band, and a second compound in a second energy band different from the first energy band.
A first step of applying a pattern forming material comprising a polymer that generates an acid when irradiated with an energy beam onto a semiconductor substrate to form a resist film; and a mask having a desired pattern shape on the resist film. A second energy beam irradiating a first energy beam through the compound to generate a base from the compound in an exposed portion of the resist film with the first energy beam; and a second energy beam to the resist film. By generating acid from the polymer on the entire surface of the resist film by irradiating the entire surface of the resist film, in the exposed portion of the first energy beam in the resist film, generated from the polymer generated from the base and the polymer generated from the compound A third step of neutralizing an acid; and supplying a metal alkoxide to the resist film to form a first energy in the resist film. A fourth step of forming a metal oxide film on the surface of the unexposed portion of the negative beam, and a dry etching of the resist film using the metal oxide film as a mask to form a resist pattern made of the resist film. 5. A pattern forming method, comprising: 10. The pattern forming method according to claim 9, wherein the fourth step includes a step of absorbing water in an unexposed portion of the resist film with the first energy beam. 11. A polymer that generates an acid when irradiated with a first energy beam in a first energy band, and a second energy band in a second energy band different from the first energy band.
A first step of applying a pattern-forming material comprising a compound that generates a base when irradiated with an energy beam onto a semiconductor substrate to form a resist film; and applying a first energy beam to the resist film. A second step of irradiating the entire surface to generate an acid from the polymer in the resist film, and irradiating the resist film with a second energy beam through a mask having a desired pattern shape, By generating a base from the compound in the second energy beam exposed portion of the resist film, the second energy beam exposed portion in the resist film is generated from the acid generated from the polymer and the compound. A third step of neutralizing a base and a metal alkoxide to the resist film to form a second gas in the resist film; A fourth step of forming a metal oxide film on the surface of the unexposed portion of the energy beam, and dry etching the resist film using the metal oxide film as a mask to form a resist pattern made of the resist film A pattern forming method, comprising: a fifth step. 12. The pattern forming method according to claim 11, wherein the fourth step includes a step of absorbing water in an unexposed portion of the resist film with the second energy beam. 13. The polymer represented by the general formula: (Provided that R ₁ represents a hydrogen atom or an alkyl group, and R ₂ and R ₃ each represent a hydrogen atom, an alkyl group, a phenyl group or an alkenyl group, each of which is independent of each other, or a cyclic alkyl group formed by both of them; , A cyclic alkenyl group,
7. A polymer represented by the formula (2), which is a cyclic alkyl group or a cyclic alkenyl group having a phenyl group).
13. The pattern forming method according to any one of items 12 to 12. 14. The polymer has the general formula: (Wherein, R ₁ represents a hydrogen atom or an alkyl group, and R ₄ represents an alkyl group, an alkenyl group, a cyclic alkyl group or a cyclic alkenyl group). The pattern forming method according to claim 6, wherein the polymer is a polymer. 15. The pattern forming method according to claim 6, wherein the compound is an acyl oxime, a benzyloxy carbonyl compound, or formamide. 16. A resist film is formed by applying on a semiconductor substrate a pattern forming material comprising a polymer containing a group that generates an acid when heated and a compound that generates a base when irradiated with an energy beam. A second step of heating the resist film to generate an acid from the polymer; and irradiating the resist film with an energy beam through a mask having a desired pattern shape. After doing
By subjecting the resist film subjected to the pattern exposure to water treatment in a gas phase or a liquid phase, a base is generated from the compound in an exposed portion of the resist film, and the generated base and the acid of the resist film are interposed. Forming a metal oxide film on the surface of the unexposed part of the resist film by exposing the resist film to a mixed gas atmosphere of water vapor and a metal alkoxide after exposing the resist film to a water vapor atmosphere; A fourth step of performing dry etching on the resist film using the metal oxide film as a mask to form a resist pattern made of the resist film. Pattern formation method. 17. A resist film is formed by applying on a semiconductor substrate a pattern forming material comprising a polymer containing a group that generates an acid when heated and a compound that generates a base when irradiated with an energy beam. A second step of heating the resist film to generate an acid from the polymer; and irradiating the resist film with an energy beam through a mask having a desired pattern shape. After doing
By holding the pattern-exposed resist film in an atmosphere of an inert gas, a base is generated from the compound in an exposed portion of the resist film, and a generated base and an acid of the resist film are neutralized. Forming a metal oxide film on the surface of the unexposed portion of the resist film by exposing the resist film to a mixed gas atmosphere of water vapor and a metal alkoxide after exposing the resist film to a water vapor atmosphere; And a fifth step of dry-etching the resist film using the metal oxide film as a mask to form a resist pattern made of the resist film. . 18. A resist film is formed by applying on a semiconductor substrate a pattern forming material comprising a polymer containing a group that generates an acid when heated and a compound that generates a base when irradiated with an energy beam. A second step of heating the resist film to generate an acid from the polymer; and irradiating the resist film with an energy beam through a mask having a desired pattern shape. After doing
By exposing the pattern-exposed resist film to an atmosphere of water vapor under an atmosphere of an inert gas, a base is generated from the compound in an exposed portion of the resist film, and the generated base and an acid of the resist film are converted. A third step of neutralizing, a fourth step of exposing the resist film to a mixed gas atmosphere of water vapor and a metal alkoxide to form a metal oxide film on a surface of an unexposed portion of the resist film, A fifth step of performing dry etching on the resist film using the metal oxide film as a mask to form a resist pattern made of the resist film.