JP2000292927A - Pattern forming material and pattern forming method by using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive pattern forming method superior in various characteristics, such as sensitivity and resolution and roughness of pattern edges, at the time of forming the pattern by development using an aqueous alkaline solution. SOLUTION: This pattern forming material contains (a) a resin obtained by additionally reacting a binder resin having a carboxylic group and/or a phenolic hydroxyl group with a compound having at least 2 vinyl ether groups in a molecule in the presence of an acid catalyst, and (b) at least a compound to be induced to produce an acid by irradiation with radiation. The above binder resin has a weight average molecular weight(Mw) to a number average molecular weight (Mn) ratio (Mw/Mn) in the range of 1.0-2.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern forming material used for microfabrication of semiconductor devices and the like, and more particularly, to generating an acid in a pattern latent image forming portion by pattern exposure to ionizing radiation such as X-rays and electron beams. The present invention relates to a pattern-forming material and a pattern-forming method that change the solubility of an irradiated part and an unirradiated part in an aqueous alkali solution by a reaction using an acid as a catalyst, and make a pattern appear in a developing step using an aqueous alkali solution as a developer.

[0002]

2. Description of the Related Art In recent years, miniaturization of semiconductor integrated circuits has been progressed with high integration, and high resolution, sensitivity, and good pattern shapes have been required for resists to be used. As such a resist, a chemically amplified resist that causes a reaction that changes the solubility in a developer by the catalytic action of an acid generated by exposure has attracted attention, and a large number of chemically amplified resist compositions have been proposed. As a positive resist, US Pat. No. 3,779,778,
The composition described in JP-A-59-45439 is known. According to the descriptions of these conventional examples, as a medium for changing the solubility, for example, a compound or a polymer containing a protecting group (acetal, t-butoxycarbonyl group, etc.) which is deprotected (separated) by an acid catalyst is disclosed. ing. In the resist containing such a medium, the exposed portion is melted by the development, and the unexposed portion remains, so that a positive pattern can appear.

In this reaction mechanism, the molecular size of the acid generated from the acid precursor and the effect of inhibiting the dissolution of the acid precursor in an alkaline developer are factors determining sensitivity and resolution. Methanesulfonic acid, trifluoromethanesulfone Onium salts having an alkylsulfonic acid such as an acid as an acid type, esters of an alkylsulfonic acid with pyrogallol, and trifluoromethanesulfonic acid of N-hydroxyimide are widely used.

In recent years, the minimum size of a semiconductor integrated circuit has become less than quarter microns, and it has become an important issue to obtain a resist pattern with high dimensional accuracy in order to improve the yield of integrated circuit production. Currently used chemical amplification type positive resists are mainly composed of alkali-soluble polymers. These polymers are composed of molecules having various molecular weights. Since polymers having different molecular weights have different solubilities in a developing solution, it has been found that unevenness (roughness) is formed on the edge of a resist pattern after development, which causes a reduction in dimensional accuracy. Japanese Patent Application Laid-Open No. 6-2 / 1994 discloses a pattern forming material which avoids this
As described in JP-A-66099, the weight average molecular weight (Mw), the number average molecular weight (Mn),
And a method for controlling the molecular weight dispersity (Mw / Mn) is known. Thereby, the roughness of the resist pattern can be improved to some extent.

[0005]

The resist containing an alkali-soluble resin whose molecular weight characteristics are controlled according to the prior art described above is:
The severe limitation of the content of low molecular weight components having high alkali solubility results in a serious drawback in that the dissolution rate of the entire resin is reduced, and as a result, the resist sensitivity is significantly reduced.

An object of the present invention is to solve the problems of the prior art and to provide a pattern forming material capable of forming a resist pattern with high sensitivity and high resolution, and a method for forming the pattern.

[0007]

Means for Solving the Problems As a result of diligent studies, the present inventors have found that an alkali-soluble binder resin and a specific structure are used as a new pattern forming material satisfying both the control of the roughness of a resist pattern and the improvement of resist sensitivity. A compound having a vinyl ether group having the following formula (1) was reacted under an acid catalyst, and attention was paid to a resin having a cross-linking structure generated by addition of a carboxyl group or a phenolic hydroxyl group of a binder resin to a vinyl ether group.

The formation of this crosslinked structure increases the molecular weight of the binder resin and is modified into a resin having low solubility in an aqueous alkali solution. The resist using this resin is
Since the crosslinked structure is cut by the catalytic reaction of the acid generated by irradiation with radiation, the original binder resin can be easily exposed.

Therefore, according to the present invention, a low molecular weight resin and a monodispersed resin having excellent alkali solubility, which could not be used as a matrix resin of a conventional resist, can be used as a binder resin. The present invention has been found to be a positive pattern forming material having a novel function of achieving uniform molecular size appearing in an exposed portion together with the improvement of the composition, and completed the present invention.

That is, the present invention relates to a resin obtained by subjecting (a) a binder resin containing a carboxyl group and / or a phenolic hydroxyl group to an acid-catalyzed addition reaction with a compound containing at least two or more vinyl ether groups in one molecule. , (B) a pattern-forming material comprising at least a compound that generates an acid upon irradiation, and a pattern-forming method using the composition.

The binder resin having a carboxyl group and / or a phenolic hydroxyl group used in the present invention includes, for example, a novolak resin obtained by polycondensing a phenol having at least one phenolic hydroxyl group with an aldehyde. . That is, phenol, o-
Cresol, m-cresol, p-cresol, 2,3
Phenols having one or more phenolic hydroxyl groups such as xylenol, 2,4-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, resorcinol, Phenols having two or more phenolic hydroxyl groups such as catechol, phloroglucin, pyrogallol,
Phenols having three or more phenolic hydroxyl groups such as hydroxyhydroquinone are exemplified. These phenols may be used alone or in combination of two or more.

Further, the above novolak resin is subjected to a fractional precipitation treatment, for example, by dissolving the resin in a good solvent, methyl isobutyl ketone, ethyl acetate, ethylene glycol monoethyl ether acetate and the like, and then hexane, chlorobenzene, xylene, toluene and diethyl ether. By pouring into a poor solvent such as, for example, the resin from which the low molecular weight has been removed is precipitated, and the obtained precipitate is further fractionated to obtain a desired molecular weight, a number average molecular weight (Mn) with respect to a weight average molecular weight (Mw). (Mw / Mn, hereinafter referred to as polydispersity).

Further, an alkali-soluble resin such as a vinylphenol polymer, a halogenated vinylphenol polymer, and a carboxyl group-containing polymer can also be used.

As the vinylphenol polymer,
Homopolymers of vinyl phenol and copolymers with components copolymerizable with vinyl phenol are preferred. Examples of the copolymerizable component include acrylic acid derivatives, methacrylic acid derivatives, styrene derivatives, maleic anhydride, maleic imide derivatives, and acrylonitrile.

Examples of the halogenated vinyl phenol polymer include 4-vinyl-2-chlorophenol and 4-vinyl-2-chlorophenol.
Vinyl-2,6-dichlorophenol, 4-vinyl-2
Polymers in which vinylphenols such as -bromophenol and 4-vinyl-2,6-dibromophenol are used alone or in combination of two or more.

As the carboxyl group-containing polymer,
Acrylic acid derivatives, methacrylic acid derivatives, crotonic acid,
A homopolymer of a carboxyl group-containing monomer such as itaconic acid, a copolymer of two or more carboxyl group-containing monomers, or a carboxyl group-containing monomer and another copolymerizable monomer Copolymers are preferred.

The alkali-soluble binder resin obtained by the above method has a weight average molecular weight (Mw) of 2,000 to 20,
000, the ratio of the number average molecular weight (Mn) to the weight average molecular weight (Mw) (polydispersity) is in the range of 1.0 to 2.0,
Preferably, the range is 1.0 to 1.5. When the weight average molecular weight is less than 2,000, there are difficulties in developing characteristics and uniformity of the coating film. When the weight average molecular weight exceeds 20,000, the resolution is remarkably reduced. Furthermore, the polydispersity is 2.
If it exceeds 0, the degree of cross-linking by the compound containing a vinyl ether group varies, and the effect of the present invention cannot be obtained.

In the present invention, a specific polyhydroxy compound can be used as the alkali-soluble binder resin. That is, those having three or more benzene rings, three or more hydroxyl groups, and two or less hydroxyl groups in one benzene ring are preferable.

As the compound having the above structure, for example, tris (4-hydroxyphenyl) methane, tris (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, α, α, α'-tris (4-
(Hydroxyphenyl) -1-ethyl-4-isopropylbenzene, 2,6-bis [(2-hydroxy-5-methylphenyl) methyl] -4-methylphenol, 2,
2'-methylenebis [6-[(2-hydroxy-5-methylphenyl) methyl] -4-methylphenol], 4
-[Bis (4-hydroxyphenyl) methyl] -2-methoxyphenol, 4,4 ', 4 ", 4"'-(1,2-
Ethanediylidene) tetrakisphenol, 4,4 ',
4 ″, 4 ′ ″-(1,2-ethanediylidene) tetrakis [2-methylphenol], 4,6-bis [(4-hydroxyphenyl) methyl] -1,3-benzenedio-
2,6-bis (4-hydroxyphenyl) methyl-
4-methylphenol, 4,4 ′, 4 ″, 4 ′ ″-(1,
4-phenylenedimethylidyne) tetrakisphenol,
C-undecyl calix [4] resorcinol arene,
Methyl calix [4] resorcinol arene, and the above phenols include hydroxybenzyl, hydroxyalkylbenzyl, dihydroxybenzyl, halogen, alkyl, cycloalkyl, alkoxy, acyl, acyloxy, nitro, hydroxyl, cyano, acyl halide, carboxyl, alcohol, Examples include compounds having at least one type of substituent selected from alkyl halides and the like.

The compound containing a vinyl ether group used in the present invention is preferably a compound containing at least two vinyl ether groups in one molecule. For example, phenols having two or more phenolic hydroxyl groups such as resorcinol, catechol, and hydroquinone;
Phenols having three or more phenolic hydroxyl groups such as phloroglucin, pyrogallol, and hydroxyhydroquinone, bisphenols, trisphenols, trinuclear phenols, and some or all of the hydrogen atoms of the hydroxyl groups of tetrakisphenols are ethyl vinyl ether A compound substituted with at least one selected from a group, a methyl vinyl ether group and a vinyl ether group is preferred.

Cycloalkanes, biphenyls,
In naphthalenes and anthracenes, a compound having two or more hydroxyl groups or glycoloyl groups has a part or all of the hydrogen atoms of the hydroxyl group substituted with at least one selected from an ethyl vinyl ether group, a methyl vinyl ether group, and a vinyl ether group. Compounds can also be used.

The content of the vinyl ether group-containing compound of the present invention is desirably from 10 to 100 parts by weight based on 100 parts by weight of the alkali-soluble binder resin. When the content is within this range, it is possible to give a satisfactory pattern shape with sufficient sensitivity to radiation and suppressed roughness. If the content is less than 10 parts by weight, the effect of the present invention cannot be obtained, and if the content is more than 100 parts by weight, sensitivity is lowered, which is not preferable.

The resist composition of the present invention includes, for example,
Surfactants for preventing striation (uneven coating) and improving developability, bisphenols, trisphenolalkanes, trinuclear phenols, tetrakisphenols for adjusting the dissolution rate of resin Or a compound containing a protective group (acetal group, ketal group, t-butoxycarbonyl group, etc.) which is deprotected (separated) by an acid catalyst, a polymer containing a protecting group for a resist solution, and a non-acid catalyst. A basic compound for suppressing diffusion to the exposed portion, an ion dissociating compound such as onium halide, and a humectant such as tetraethylene glycol can be added as necessary.

[0024]

Next, specific examples and comparative examples of the present invention will be described. It should be noted that these examples are merely examples under suitable specific conditions within the scope of the present invention, and the present invention is not limited only to these examples.

(Synthesis example 1 of vinyl ether) An example of synthesis of a compound having a vinyl ether group is shown below. Dissolve 2.5 g of tris (4-hydroxyphenyl) methane in 50 ml of dimethyl sulfoxide. 10 ml of hexane was added to 1.8 g of sodium hydride (in 50% solid oil) to dissolve the dispersion medium, and the mixture was poured at 25 ° C.
The reaction was performed while stirring for an hour. In addition, 2
-Chloroethyl vinyl ether (10 g) was added dropwise at 70 ° C.
For 12 hours. The reaction mixture is dropped into 1000 ml of water to precipitate the product. The aqueous solution containing the product was transferred to a separating funnel and extracted with 200 ml of diethyl ether. The ether solution is a 2N NaOH aqueous solution 50
Wash by adding ml and wash with water until neutral. The ether solution washed with water was concentrated under reduced pressure to obtain a product. From the infrared absorption spectrum and the NMR spectrum analysis of this product, it was confirmed that all of the hydrogen atoms of the three hydroxyl groups of tris (4-hydroxyphenyl) methane were substituted with ethyl vinyl ether groups.

(Synthesis example 2 of vinyl ether) Tris (4-hydroxyphenyl) of the synthesis example 1 of vinyl ether described above
Similar results were obtained using phloroglucin instead of methane.

(Synthesis example 3 of vinyl ether) Tris (4-hydroxyphenyl) of synthesis example 1 of vinyl ether described above
Similar results were obtained using bis (p-hydroxyphenyl) methane instead of methane.

(Synthesis Example 4 of Vinyl Ether) Similar results were obtained by using vinyl chloride instead of 2-chloroethyl vinyl ether in Synthesis Example 1 of vinyl ether described above.

(Resin Synthesis Example 1) A resin synthesis example obtained by an acid-catalyzed addition reaction of an alkali-soluble binder resin and a compound containing a vinyl ether group will be described below.

Α, α, α'-tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene
-Hydroxybenzyl group hexa-substituted product (positions of 4-hydroxybenzyl group substituted at 4-hydroxyphenyl group are at positions 2 and 6) (molecular weight: 1060) : 3 μm / sec): 2.0 g and the compound of the synthetic example 1 of vinyl ether: 1.0 g are dissolved in 50 ml of 1,4-dioxane. To this was added 0.01 g of pyridinium p-toluenesulfonate and reacted at 25 ° C. for 6 hours.
Thereafter, the reaction solution was concentrated under reduced pressure to obtain a white solid. This solid was dissolved in ethyl acetate, transferred to a separating funnel,
Wash with 50 ml of N NaOH and wash with water until neutral. The ethyl acetate solution washed with water is concentrated under reduced pressure to precipitate a solid in hexane. After filtration, vacuum drying gave the product.

The product was confirmed to be a resin having a weight average molecular weight (Mw) of 5100 and a polydispersity of 2.5 by GPC (using a differential refractive index detector). It was also found that the dissolution rate of the resin in a 2.38% by weight aqueous solution of tetramethylammonium hydroxide was as small as 0.1 nm / sec.

(Resin Synthesis Example 2) Vinyl ether compound of Resin Synthesis Example 1 (vinyl ether synthesis example 1)
Similar results were obtained using the same vinyl ether compound: 0.6 g instead of 0 g.

(Resin Synthesis Example 3) A similar result was obtained by using 1,4-cyclohexanedimethanol divinyl ether instead of the vinyl ether compound of Resin Synthesis Example 1 described above.

(Resin Synthesis Example 4) Instead of the vinyl ether compound of Resin Synthesis Example 1 described above, vinyl ether synthesis example 2
Similar results were obtained using the vinyl ether compound of

(Resin Synthesis Example 5) Instead of the vinyl ether compound of Resin Synthesis Example 1 described above, Vinyl Ether Synthesis Example 3
Similar results were obtained using the vinyl ether compound of

(Resin Synthesis Example 6) α, α, α'-tris (4-hydroxyphenyl) -1 of Resin Synthesis Example 1 described above.
Similar results were obtained using poly (methacrylic acid) (Mw: 7000, polydispersity: 1.07) in place of the hexa-substituted 4-hydroxybenzyl group of -ethyl-4-isopropylbenzene.

(Resin Synthesis Example 7) α, α, α'-tris (4-hydroxyphenyl) -1 of Resin Synthesis Example 1 described above.
Similar results were obtained using methyl calix [4] resorcinarene instead of hexa-substituted 4-hydroxybenzyl group of -ethyl-4-isopropylbenzene.

Example 1 Resin of Resin Synthesis Example 1: 100
4 parts by weight of tri-substituted ester of pyrogallol and ethanesulfonic acid as an acid precursor were dissolved in 2-heptanone to prepare a solution having a solid content of 15% by weight. This solution was filtered using a Teflon membrane filter having a pore size of 0.2 μm to obtain a resist solution.

The above-mentioned resist solution was dropped on a silicon wafer, and after spin coating, heat-treated at 100 ° C. for 5 minutes to obtain a 0.35
A μm-thick resist film was obtained. The substrate is irradiated with an electron beam by changing the irradiation amount in a stepwise manner with an electron beam lithography system (electron beam acceleration voltage is 30 kV), and then heat-treated at 100 ° C. for 2 minutes. Accelerated reactions to increase solubility.

After the above-mentioned heat treatment, an aqueous solution containing 2.38% by weight of tetramethylammonium hydroxide was immersed in a developing solution for 30 seconds, and the residual film thickness of the irradiated portion was measured. Electron beam sensitivity characteristics were determined from the relationship between the residual film thickness and the amount of electron beam irradiation. The sensitivity curve of the present invention showed a high sensitivity of 7.0 μC / cm ² and a high contrast without a film loss (FIG. 1).

A line and space pattern of 0.2 μm is drawn on the substrate coated with the resist solution of the present invention with an irradiation amount of 11.0 μC / cm ² using an electron beam drawing apparatus (acceleration voltage of electron beam is 50 kV). did. Heat treatment at 100 ° C. for 2 minutes promoted a reaction for increasing the solubility of the latent image portion in an aqueous alkaline solution. After the above heat treatment, an aqueous solution containing 2.38% by weight of tetramethylammonium hydroxide was immersed for 50 seconds in a developing solution to obtain a resist pattern.
It was found that the resist pattern of the present invention had a rectangular cross-sectional shape, and the unevenness of the pattern edge was as small as 10 nm or less.

Example 2 The procedure of Example 1 was followed except that Resin Synthesis Example 3 was used instead of Resin Synthesis Example 1. In this embodiment, the same result as in the first embodiment was obtained.

Example 3 The procedure of Example 1 was followed except that Resin Synthesis Example 4 was used instead of Resin Synthesis Example 1. In this embodiment, the same result as in the first embodiment was obtained.

Example 4 The procedure of Example 1 was followed except that Resin Synthesis Example 5 was used instead of Resin Synthesis Example 1. In this embodiment, the same result as in the first embodiment was obtained.

Example 5 The procedure of Example 1 was followed except that Resin Synthesis Example 6 was used instead of Resin Synthesis Example 1. In this embodiment, the same result as in the first embodiment was obtained.

Example 6 The procedure of Example 1 was followed except that Resin Synthesis Example 7 was used instead of Resin Synthesis Example 1. In this embodiment, the same result as in the first embodiment was obtained.

(Comparative Example 1): Conventional Example In Example 1, the resin of Synthesis Example 5: m, p-cresol novolak resin (Mw: 77) instead of 100 parts by weight
00, polydispersity: 4.9) (Dissolution rate in 2.38% by weight aqueous solution of tetramethylammonium hydroxide: 22
nm / sec): 85 parts by weight, poly (p-vinylphenol) having an ethoxyethyl group as an acid-decomposable group (80% introduction of ethoxyethyl groups): 15 parts by weight Performed according to method. As a result, the resist showed an electron beam sensitivity of 3.0 μC / cm ² , but the unevenness of a 0.2 μm pattern formed by an electron beam lithography apparatus was 2 μm.
It was found to be as large as 0 nm or more.

Example 7 An example in which the resist composition of Example 1 is applied to a process for processing a photomask using an electron beam lithography technique (acceleration voltage of an electron beam is 50 kV) will be described below.

First, the above-described resist was dropped on a blank for photomask (manufactured by HOYA Corporation) having a two-layer light-shielding film of a chromium film and a chromium oxide film formed on a quartz substrate. Heat treatment was performed for a minute to obtain a resist film having a thickness of 0.3 μm. A 0.25 μm line and space pattern was drawn on this substrate at an irradiation dose of 11.0 μC / cm ² using an electron beam writing apparatus (acceleration voltage of the electron beam was 50 kV), followed by heat treatment at 100 ° C. for 5 minutes. This accelerated the reaction to increase the solubility of the latent image portion in an aqueous alkali solution.

After the above heat treatment, an aqueous solution containing 2.38% by weight of tetramethylammonium hydroxide was immersed in a developing solution for 50 seconds to obtain a resist pattern. The resist pattern of the present invention had a rectangular cross section and a line width of 0.5 μm as designed. Next, dry etching of the chromium two-layer film was performed by reactive ion etching with a mixed gas of CH ₂ Cl ₂ and O _{2 using} the development pattern as a mask. The resist was removed with methyl acetate cellosolve, and the etched shape of the chromium film was confirmed by an electron microscope. As a result, a pattern having a vertical cross-sectional shape was confirmed.

In the above embodiment, an example was described in which an electron beam was used to form a latent image. However, since an acid precursor generates an acid similarly to electron beam irradiation even when irradiated with actinic radiation other than an electron beam,
In the present invention, even when a latent image was formed using actinic radiation such as X-rays in addition to the electron beam, the same results as in the above example could be obtained.

[0052]

According to the present invention, a resist pattern having high sensitivity and excellent resolution with respect to ultraviolet rays, far ultraviolet rays, electron beams, X-rays, and other actinic radiations can be formed, and can be developed with an alkaline aqueous solution. Therefore, it is suitably used as a resist for ultrafine processing in the manufacture of semiconductor devices such as ICs and LSIs. Further, according to the pattern forming method of the present invention, the throughput and the yield at the time of manufacturing an integrated circuit are improved.

[Brief description of the drawings]

FIG. 1 is a graph showing electron beam sensitivity characteristics of a resist in Example 1 of the present invention.

[Explanation of symbols]

 1: Sensitivity characteristic curve of the pattern forming material of Example 1.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 61/14 C08L 61/14 5F046 G03F 7/38 511 G03F 7/38 511 H01L 21/027 C08G 8/36 // C08G 8/36 H01L 21/30 502R 569A (72) Inventor Yui Arai 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo F-term in Central Research Laboratory, Hitachi, Ltd. F-term (reference) 2H025 AA01 AA02 AA03 AA04 AB16 AB17 AC01 AC05 AC06 AD03 BE10 BJ10 CB20 CB21 CB29 CB41 CB43 CB55 CB56 FA01 FA12 FA17 2H096 AA25 AA27 BA11 DA01 EA06 EA07 FA01 GA08 4J002 BC121 BG011 CC041 CC051 CC061 EV236 EV246 FD206 GP03 4J033 CA01 CA12 ACOB AJA42J BA02S BA03P BA15S BB01P BB03P BC04H BC43H BC43S CA01 CA04 CA3 1 DA04 HA11 HA19 HA61 JA38 5F046 BA07 JA04 LA12 LA18

Claims (6)

[Claims] 1. A resin obtained by subjecting a binder resin containing a carboxyl group and / or a phenolic hydroxyl group to an acid-catalyzed addition reaction with a compound containing at least two or more vinyl ether groups in one molecule, And (b) a compound which generates an acid upon irradiation. 2. The pattern-forming material according to claim 1, wherein the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the binder resin of the component (a).
Is in the range of 1.0 to 2.0. 3. The pattern-forming material according to claim 1, wherein the binder resin as the component (a) has three or more benzene rings, three or more hydroxyl groups, and one benzene ring. A pattern-forming material, which is a polyhydroxy compound having two or less hydroxyl groups. 4. The pattern-forming material according to claim 1, wherein the compound having a vinyl ether group of the component (a) has a vinyl ether group directly or via a linking group at a hydroxyl group portion of a compound having at least two hydroxyl groups. A pattern-forming material characterized by having a structure in which it is bonded together. 5. A step of applying the pattern-forming material according to claim 1 to a substrate to form a coating film, a heat treatment step for removing a coating solvent, and applying radiation to the coating film. A pattern forming method comprising: a step of forming a predetermined pattern latent image; a step of accelerating an acid-catalyzed reaction; and a developing step of developing a pattern using an alkaline aqueous solution as a developing solution. 6. The pattern forming method according to claim 5, wherein an electron beam or an X-ray is used as a radiation source.