WO2008069014A1

WO2008069014A1 - Surface modifier for resist and method for the formation of resist patterns with the same

Info

Publication number: WO2008069014A1
Application number: PCT/JP2007/072362
Authority: WO
Inventors: Tomoya Kumagai; Jun Koshiyama; Kazumasa Wakiya; Atsushi Sawano
Original assignee: Tokyo Ohka Kogyo Co., Ltd.
Priority date: 2006-12-08
Filing date: 2007-11-19
Publication date: 2008-06-12
Also published as: TW200900883A

Abstract

The invention provides a surface modifier for resist which can modify the surface of photoresist film to enhance the wettability of the surface by a developer sufficiently and which is excellent in safety; and a method for the formation of resist patterns with the modifier. A surface modifier for resist which consists of an aqueous solution of at least one amine oxide represented by the general formula (1) or (2): (1) (2) wherein R1 is either alkyl of 8 to 20 carbon atoms which may be interrupted by oxygen or hydroxyalkyl; and n and m are each an integer of 1 to 5.

Description

Specification

Resist surface modifier and resist pattern forming method using the same

TECHNICAL FIELD [0001] The present invention relates to a resist surface modifier capable of modifying a photoresist film surface and improving wettability to a developer, and a resist pattern forming method using the same.

Background art

[0002] In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization is rapidly progressing due to advances in lithography technology. As a method for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, in the past, ultraviolet rays such as g-line (436nm) and i-line (365ηm) were used. Currently, KrF excimer laser (248 nm) and ArF excimer laser (193 nm) are used. Mass production of the used semiconductor devices has started, and F-excimer lasers (157 nm) with shorter wavelengths than these excimer lasers have also been tested

2

Debate is taking place.

[0003] Currently, a resin having a fluorine atom or a siloxane bond in a resin skeleton is used as a base resin of a photoresist composition used at a short wavelength of 200 nm or less because of excellent transparency. However, since fluorine and siloxane are highly water-repellent materials, the developer does not spread evenly, and there is a risk of developing failure.

Therefore, recently, the photoresist film surface is treated with an aqueous solution containing a fluorosurfactant having an amine salt of carboxylic acid or sulfonic acid as a hydrophilic group to improve the wettability of the developer, and then developed. There has been proposed a technique for performing (see Patent Document 1).

Patent Document 1: JP 2006-259760

Disclosure of the invention

Problems to be solved by the invention

[0005] However, such a fluorosurfactant described in Patent Document 1 cannot sufficiently increase the wettability of the photoresist film surface to a desired level, and is also toxic or Since many of them have high persistence, there is a need for a resist surface modifier that can improve the wettability to the developer by modifying the photoresist film surface and has excellent safety. It was done.

[0006] The present invention has been made in view of such conventional circumstances, and can improve the wettability with respect to the developer by modifying the photoresist film surface and is excellent in safety. It is an object of the present invention to provide a resist surface modifier and a resist pattern forming method using the same.

Means for solving the problem

[0007] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using an aqueous solution containing a specific amine oxide compound, and the present invention is completed. It came to.

That is, a first aspect of the present invention is a resist surface modifier comprising an aqueous solution containing at least one amine oxide compound represented by the following general formulas (1) and (2).

[Chemical 1

ΐη _{η + 1}

1- N— O

I

lmH2m + l

C „H ₂ „ OH

1- N- →-O (2)

I

(In the formulas (1) and (2), R ¹ represents an alkyl or hydroxyalkyl group having 8 to 20 carbon atoms which may be interrupted by an oxygen atom, and n and m represent an integer of !! to 5) )

[0009] Further, the second aspect of the present invention includes a step of providing a photoresist film on a substrate, a step of selectively exposing the photoresist film through a mask pattern, and a step of exposing the photoresist film after exposure. A resist pattern forming method comprising: a step of treating with a resist surface modifier of the invention; and a step of developing the photoresist film after the treatment with the resist surface modifier.

The invention's effect

According to the present invention, the photoresist film surface can be modified to be hydrophilic. Therefore, By treating the photoresist film with a resist surface modifier before development, the wettability with respect to the developer can be sufficiently increased and the occurrence of defective development can be prevented.

BEST MODE FOR CARRYING OUT THE INVENTION

[0011] [Resist surface modifier]

The resist surface modifier of the present invention comprises an aqueous solution containing a specific amine oxide compound. Hereinafter, each component constituting the resist surface modifier will be described in detail.

[0012] <Aminoxide compound>

As the amine oxide compound contained in the resist surface modifier, at least one amine oxide compound represented by the following general formulas (1) and (2) is used.

[Chemical 2] 1- N— I- O

I

MH2m + l

C „H ₂ „ OH

1- N- →-O (2)

I

R ¹ in the formulas (1) and (2) is a linear or branched long-chain alkyl group having 8 to 20 carbon atoms, such as an octyl group, a noel group, a decyl group, a lauryl group. , Pentadecyl group, myristyl group, palmityl group, stearyl group and the like. Examples of such a long-chain alkyl group in which the carbon chain may be interrupted by an oxygen atom include the following general formulas (5) and (compounds). ^{_{R 4 - (0CH 2 CH2)}} r (5) R 4 - (OCH 2 CH 2 CH 2) - (6)

(In the formulas (5) and (6), R ⁴ represents an alkyl group, and p and q represent an integer such that the total number of carbon atoms in the formula is 8 to 20.)

[0014] The two lower alkyl groups in the formula (1) are preferably two lower alkyl groups having 1 to 3 carbon atoms such as a methyl group, an ethyl group, and a propyl group, in the formula (2). As the lower hydroxyalkyl group, a lower hydroxyalkyl group having 1 to 4 carbon atoms such as a methylol group, a hydroxyethyl group, a hydroxypropyl group, or a hydroxybutyl group is more preferable. These may be either straight chain or branched.

[0015] The two lower alkyl groups in the formula (1) and the two lower hydroxyalkyl groups in the formula (2) are preferably the same as each other, but may be different from each other. Therefore, preferred examples of the amine oxide compound represented by the formula (1) include octyl dimethyl amine oxide, dodecyl dimethyl amine oxide, decyl dimethyl amine oxide, lauryl dimethyl amine oxide, cetyl dimethyl amine oxide, stearyl. Long-chain alkyl dimers such as dimethylaminoxide, isohexyljetylamine oxide, nonyljetylamine oxide, lauryljetylamine oxide, isopentadecylmethylethylamine oxide, stearylmethylpropylamine oxide Lower alkylamine oxides are mentioned, and preferable examples of the amineoxide compound represented by the formula (2) include lauryl di (hydroxyethyl) amine oxide, cetyljetanol amine oxide, stearyl di (hydroxide). Long-chain alkyldi-lower alkanolamines such as til) amineoxides dodecyloxyethoxyethoxyethoxydidi (methyl) amineoxides, long-chain alkyloxyalkyldi-lower alkylamine oxides such as stearyloxysutyldi (methyl) amineoxides It is done.

[0016] The resist surface modifier may further contain at least one amine compound represented by the following general formulas (3) and (4), if desired. H _2n + iC _n -N— (3)

I

R ³ R ²

I

HOH _2n C _n -N— (4)

I

R ³

(In the formulas (3) and (4), R ² and R ³ each independently represent an alkyl group or hydroxyalkyl group having 8 to 20 carbon atoms which may be interrupted by an oxygen atom, and n represents 1 to 5 [0017] R ² and R ³ in the formulas (3) and (4) are linear or branched long-chain alkyl groups having 8 to 20 carbon atoms, such as an octyl group and a Noel group. Decyl group, lauryl group, pentadecyl group, myristyl group, palmityl group, stearyl group and the like. Examples of such long-chain alkyl groups in which the carbon chain may be interrupted by an oxygen atom include those represented by formulas (5) and (6).

[0018] As one lower alkyl group in the formula (3), one lower alkyl group having 1 to 3 carbon atoms such as a methyl group, an ethyl group, and a propyl group is more preferable. As the lower hydroxyalkyl group, a lower hydroxyalkyl group having 1 to 4 carbon atoms such as a methylol group, a hydroxyethyl group, a hydroxypropyl group, or a hydroxybutyl group is more preferable. These may be either straight chain or branched.

[0019] R ² and R ³ in the formulas (3) and (4) are preferably the same as each other, but may be different from each other. Accordingly, preferred examples of the amine oxide compound represented by the formula (3) include dioctylmethylamine oxide, didodecylmethylamine oxide, didecylmethylamine oxide, dilaurylmethylamine oxide, dicetylmethyl. Amine oxide, distearylmethylamine oxide, diisohexylethylamine oxide, dinonylethylamine oxide, dilaurylethylamine oxide, diisopentadecylethylamine oxide, distearylpropylamine oxide Di-long-chain alkyl lower alkyl amine oxides such as the amine oxide compounds represented by formula (4) are preferred! /, Examples As di-long-chain alkyl lower alkyls such as dilauryl (hydroxyethyl) amine oxide, dicetyl ethanolamine oxide, distearyl (hydroxyethyl) amine oxide, noramine amine oxide or didodecyloxyethoxyethoxyethyl. Examples thereof include di-long-chain alkyloxyalkyl lower alkylamine oxides such as (methyl) amine oxide and distearyloxetyl (methyl) amine oxide.

Here, the amine oxide compound represented by the formulas (3) and (4) is insoluble in an aqueous solvent alone, but is mixed with the amine oxide compound represented by the formulas (1) and (2). In particular, it can be dissolved in an aqueous solvent. Further, by mixing the amine oxide compound represented by the formulas (1) and (2) and the amine oxide compound represented by the formulas (3) and (4), the compounds represented by the formulas (1) and (2) are represented. The surface modification effect of the photoresist film can be improved as compared with the case where only the amine oxide compound is used.

When the resist surface modifier contains the amine oxide compound represented by the formulas (3) and (4), the amine oxide compound represented by the formulas (1) and (2) and the formulas (3) and (4) ) Is preferably 99:;! To 80:20, more preferably 95: 5-85: 15, more preferably /. When the proportion of the amine oxide compound represented by the formulas (1) and (2) is larger than this range, the surface modification effect tends to decrease. There is.

[0022] The total content of these amineoxide compounds is preferably 0.1 mass ppm to 10 mass% in the resist surface modifier. 0. If less than 1 ppm by mass, the surface modification effect of the photoresist film is reduced, and it becomes difficult to disperse and diffuse on the photoresist film surface. If it exceeds 10% by mass, the resist surface modifier penetrates into the photoresist film and the photoresist film. May dissolve and the pattern shape may deteriorate.

[0023] <Solvent>

As the solvent for the resist surface modifier, it is preferable to use water alone, but if desired, a mixed solvent of water and a water-miscible organic solvent can be used. Examples of the water-miscible organic solvent include monohydric alcohol organic solvents such as methanol, ethanol, and propanol, ethylene glycol, propylene glycol, diethylene glycol, glycerin, alkyl etherified products and esterified products thereof. Preferred are monohydric alcohol-based organic solvents That's right.

[0024] The blending amount of the water-miscible organic solvent is preferably 0.01 to 10% by mass in the solvent, more preferably 0.1 to 5% by mass. By blending the water-miscible organic solvent in this manner, the resist surface modifier can be efficiently dispersed and diffused on the photoresist film surface.

[0025] <Other ingredients>

If desired, the resist surface modifier may further contain an anionic surfactant. Examples of the anionic surfactant include a known alkyl group having 8 to 20 carbon atoms (a hydroxyl group and a carboxyl group may be included, and a phenyl group and an alkylene oxide group may be interposed in the middle of the alkyl chain). May be a straight chain or a branched chain), and a neutral salt such as an alkyl sulfate, an alkyl sulfonate, an alkyl phosphate or the like.

[0026] By containing this anionic surfactant, it is possible to reduce the surface tension of the resist surface modifier, and at the same time, the surface modification effect of the photoresist film is improved as compared with the case where only the amine oxide compound is contained. Can be improved.

[0027] When the anionic surfactant is contained in the resist surface modifier, the content of the amine oxide compound in the resist surface modifier is from 1 mass ppm to! Mass%, preferably from 10 mass ppm to 1000 mass ppm, more preferred <30 mass ppm to 300 mass ppm, particularly preferred <30 mass ppm to 200 mass ppm. The content of the anionic surfactant in the resist surface modifier is 1 mass ppm to;! Mass%, preferably 10 mass ppm to 2000 mass ppm, more preferably <is 50 mass ppm to 1000 mass. ppm, particularly preferred <200 mass ppm to 700 mass ppm is preferred.

[0028] In addition, as the resist surface modifier, polyalkylene glycol (for example, polyethylene glycolol, polypropylene glycolol, poly (ethyleneglycolanol propylene glycol)) or an alkyl ether thereof (for example, methyl ether, Ethyl ether). These content in the resist surface modifying agent, 1 wt ppm to 5 mass ^_0/0 preferably fixture 0.5; more preferably 1-3 mass ^_0/0!. By containing this polyalkylene glycol or its alkyl ether, it is possible to efficiently disperse and diffuse the resist surface modifier on the photoresist film surface. [0029] The resist surface modifier may further contain a soluble polymer containing a nitrogen atom in the molecular structure, that is, a polymer soluble in the solvent used, if desired. This nitrogen atom may be contained in the side chain as a nitrogen-containing substituent which may be contained in the backbone molecular chain of the polymer! /.

[0030] Examples of the soluble polymer in which the nitrogen atom is contained in the basic molecular chain include, for example, a polymer of a lower alkylimine or another monomer that forms a water-soluble polymer alone with a lower alkyleneimine. A copolymer may be mentioned, but polyethyleneimine is particularly preferable because it is easily available. This polyethyleneimine can be easily produced, for example, by ring-closing polymerization of ethyleneimine in the presence of an acid catalyst such as carbon dioxide, chlorine, hydrobromic acid, P-toluenesulfonic acid, etc. The power of manpower as S

[0031] Further, examples of the soluble polymer containing a nitrogen-containing substituent in the side chain include polymers or copolymers of unsaturated hydrocarbons having an amino group or a substituted amino group or a nitrogen-containing heterocyclic group. An example of the unsaturated hydrocarbon polymer having an amino group is polyallylamine. This polyallylamine can be easily obtained, for example, by heating allylamine hydrochloride in the presence of a radical polymerization initiator.

[0032] Preferred as a soluble polymer containing a nitrogen-containing substituent used in the present invention! / Is a monomer unit having a nitrogen-containing heterocyclic group represented by the following general formula (7) It is a water-soluble resin containing

[Chemical 5]

(In the formula (7), R ⁵ represents a hydrogen atom or a methyl group, and X represents a nitrogen-containing heterocyclic group.) [0033] Examples of X in the formula (7) include a pyrrolyl group, an imidazolyl group, and a pyrazolyl group. Group S, thiazolinol group, oxazolyl group, isoxazolyl group, pyridyl group, birazyl group, pyrimidyl group, pyridazyl group, triazolyl group, indolyl group, quinolyl group, butyrolatatum group, force prolatatam group, and other forces S It may be a nitrogen heterocyclic group. These heterocyclic groups The bonding position of may be a nitrogen atom or a carbon atom without particular limitation.

[0034] The soluble polymer containing a monomer unit having such a nitrogen-containing heterocyclic group is, for example, a monomer having a nitrogen-containing heterocyclic group represented by the following general formula (8), or this monomer: Can be produced by polymerizing or copolymerizing a mixture of monomer and water-soluble heavy CX R ———— a nitrogen atom that forms a coalescence! /, Monomer. This polymerization or copolymerization can be performed by a conventional method for producing a polymer or copolymer such as a solution polymerization method or a suspension polymerization method.

[Chemical 6]

CH

(In Formula (8), R ⁵ and X have the same meanings as in Formula ( ⁷ ).)

[0035] Preferable monomers represented by the formula (8) include butyrimidazole, butyl imidazoline, butyrpyridine, butyrpyrrolidone, vinylenomonoreforin, and butyr strength prolactam. Burimidazole, buriumidazoline, and burpi oral lidon are particularly preferred.

[0036] Further, as a monomer that does not contain a nitrogen atom and forms a water-soluble polymer alone,

For example, a hydroxyalkyl ester of butyl alcohol, acrylic acid or methacrylic acid. These monomers may be used alone or in combination of two or more.

[0037] When a monomer having a nitrogen-containing heterocyclic group and a monomer not containing a nitrogen atom that forms a water-soluble polymer alone are copolymerized, the mixing ratio is from 10: 0 to 1: 9 is preferred, 9:;! To 2: 8 is more preferred. Further, the mass average molecular weight of the copolymer is preferably from 500 to 150,000, more preferably from 1,000 to 50,000. As this copolymer, a copolymer containing a cationic monomer is particularly preferable. Such copolymers are commercially available, for example, from the company BASF (product names “LUVITEC VPI55K72WJ” and “Sokalan HP56 I”). , Polyburuimidazoline is sold by Toso Company It is.

[0038] The content of the soluble polymer in the resist surface modifier is preferably 0.1 mass ppm to 10 mass%, more preferably 0.5 mass ppm to 5 mass%. By containing this soluble polymer, the surface of the photoresist film can be further modified to be hydrophilic, the wettability with respect to the developer can be improved, and the occurrence of development failure can be prevented.

[0039] If desired, the resist surface modifier may be adjusted to an acidity of pH 6 or lower by adding an acid, or a basic compound having a pH of 8 or higher by adding an ammine compound or quaternary ammonium hydroxide. You may adjust it. By adding these, it is possible to prevent the resist surface modifier from deteriorating with time.

[0040] Examples of such acids include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, oxalic acid, fumaric acid, maleic acid, phthalic acid, peracetic acid, sulfuric acid, trifluoroacetic acid, and ascorbic acid. Is mentioned.

[0041] Examples of the amine compounds include monoethanolamine 2- (2-aminoethoxy) ethanol, and the quaternary ammonium hydroxides include tetramethylammonium hydroxide, tetraethylammonium. Hydroxide, 2-hydroxyethyltrimethylammonium hydroxide, tetrapropylammonium hydroxide, methyltripropylammonium hydroxide, tetraptylammonium hydroxide, methyltributylammonium And hydroxides.

[0042] Such a resist surface modifier can modify the photoresist film surface to be hydrophilic. Therefore, by treating the photoresist film with this resist surface modifier before development, the wettability with respect to the developer can be improved and the development failure can be prevented.

[0043] [Resist pattern formation method]

The resist pattern forming method of the present invention comprises a step of providing a photoresist film on a substrate, a step of selectively exposing the photoresist film via a mask pattern, and a photoresist surface modifier of the present invention after the exposed photoresist film. And a step of developing the photoresist film after the treatment with the resist surface modifier. Hereinafter, each step of the resist pattern forming method will be described in detail.

[0044] First, a photoresist film is provided on a substrate. As a substrate, silicon wafer is generally used. However, it is not particularly limited. In addition, a known photoresist composition for forming a photoresist film can be used S, and the resist surface modifier of the present invention is based on a resin having a fluorine atom or a siloxane bond in the resin skeleton. This is particularly effective when using a photoresist composition as a resin. In this step, a photoresist composition solution is applied onto a substrate such as a silicon wafer using a spinner and dried to form a photoresist film.

Next, the photoresist film is selectively exposed through the mask pattern. In this step, the formed photoresist film is selectively exposed through a mask pattern to form a latent image, and then subjected to post-exposure heat treatment (PEB).

Next, the exposed photoresist film is treated with the resist surface modifier of the present invention. In this step, a resist surface modifier is applied to the surface of the photoresist film with a spinner and dried. By this treatment, the surface of the photoresist film is modified to be hydrophilic.

Next, the photoresist film after the treatment with the resist surface modifier is developed. In this step, for example 1; the development processing is performed using a 10 mass ^_0/0 alkali current image liquid such as tetramethylammonium Niu arm hydroxide aqueous solution. As described above, the surface of the photoresist film is modified to be hydrophilic by treatment with the resist surface modifier of the present invention, so that the wettability of the developer is increased and the development process is performed satisfactorily. Can do.

Example

[Examples 1 and 2, Comparative Example 1]

[Evaluation of wettability of photoresist film to resist surface modifier]

Apply an anti-reflective coating solution (product name "ARC-29A", manufactured by Brewer) on 8 inch silicon wafer, heat treatment at 215 ° C for 60 seconds, and reflect with 77nm thickness After providing the anti-reflection film, a photoresist (product name “TARF-P7145”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the anti-reflection film, heat-treated at 145 ° C. for 60 seconds, and a 180 nm-thick photoresist. A film was formed. The photoresist film thus obtained was exposed through a mask pattern with a 130 nm diameter contact hole using an exposure apparatus (product name “Nikon NSR-S302A” manufactured by Nikon Corporation), and then 110 ° C. For 60 seconds. Then, a resist table in which lauryl dimethylamine oxide is dissolved in deionized water to have the concentration shown in Table 1. A surface modifier was dropped on the photoresist film, and the contact angle of the resist surface modifier was measured. The results are shown in Table 1.

[0049] [Table 1]

[0050] From the results in Table 1, the resist surface modifiers of Examples 1 and 2 containing lauryl dimethylamine oxide were the resist surface modifier of Comparative Example 1 not containing lauryl dimethylamine oxide. It was confirmed that the contact angle to the photoresist film was smaller than that of the agent. Therefore, it is considered that the resist surface modifiers of Examples 1 and 2 spread efficiently over the photoresist film surface.

[0051] [Evaluation of wettability of photoresist film after surface modification to deionized water]

Apply an anti-reflective coating solution (product name "ARC-29A", manufactured by Brewer) on 8 inch silicon wafer, heat treatment at 215 ° C for 60 seconds, and reflect with 77nm thickness After providing the anti-reflection film, a photoresist (product name “TARF-P7145”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the anti-reflection film, heat-treated at 145 ° C. for 60 seconds, and a 180 nm-thick photoresist. A film was formed. The photoresist film thus obtained was exposed through a mask pattern with a 130 nm diameter contact hole using an exposure apparatus (product name “Nikon NSR-S302A” manufactured by Nikon Corporation), and then 110 ° C. For 60 seconds. Then, the silicon wafer was immersed for 60 seconds in a resist surface modifier in which lauryldimethylamine oxide was dissolved in deionized water so as to have the concentration shown in Table 2, and then dried. Thereafter, deionized water was dropped on the photoresist film and the contact angle of the deionized water was measured. The results are shown in Table 2.

Yes

[0052] [Table 2]

Lauryl dimethylamine oxide concentration Contact angle

(Mass ppm) (degree)

Example 1 5 0 0 5 5

Example 2 2 5 0 6 3

Comparative Example 1 0 7 1 [0053] From the results in Table 2, the photoresist films treated with the resist surface modifiers of Examples 1 and 2 containing lauryl dimethylamine oxide contained lauryl dimethylamine oxide. It was confirmed that the contact angle of deionized water was smaller than that of the photoresist film treated with the resist surface modifier of Comparative Example 1. Therefore, it can be considered that the developer reaches the surface of the photoresist film efficiently by treating the photoresist film with the resist surface modifier of Examples 1 and 2.

[Evaluation of developability after surface modification with resist surface modifier]

Apply an anti-reflective coating solution (product name "ARC-29A", manufactured by Brewer) on 8 inch silicon wafer, heat treatment at 215 ° C for 60 seconds, and reflect with 77nm thickness After providing the anti-reflection film, a photoresist (product name “TARF-P7145”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the anti-reflection film, heat-treated at 145 ° C. for 60 seconds, and a 180 nm-thick photoresist. A film was formed. The photoresist film thus obtained was exposed through a mask pattern with a 130 nm diameter contact hole using an exposure apparatus (product name “Nikon NSR-S302A” manufactured by Nikon Corporation), and then 110 ° C. For 60 seconds. Then, a resist surface modifier in which lauryldimethylamine oxide was dissolved in deionized water so as to have the concentration shown in Table 3 was applied to the photoresist film surface at 2000 rpm for 7 seconds and then dried. After that, a resist pattern of 130 nm contact holes was formed by developing for 60 seconds at 23 ° C. using an aqueous solution of 2.38 mass% tetramethylammonium hydroxide. The repelling of the developer at this time was visually observed. The pattern shape was observed with a scanning electron microscope and evaluated as ◯ when a good resist pattern was formed, and X when a resist pattern defect that was thought to be caused by development failure was observed. The results are shown in Table 3.

[0055] [Table 3]

From the results in Table 3, the photoresist films treated with the resist surface modifiers of Examples 1 and 2 containing lauryldimethylamine oxide contained lauryldimethylamine oxide. Compared to the photoresist film treated with the resist surface modifier of Comparative Example 1, no repelling of the developer was observed and it was confirmed that a good resist pattern was formed.

[0057] (Examples 3 to 5, Comparative Example 2)

[Evaluation of wettability of photoresist film to resist surface modifier]

Apply an anti-reflective coating solution (product name "ARC-29A", manufactured by Brewer) on 8 inch silicon wafer, heat treatment at 215 ° C for 60 seconds, and reflect with 77nm thickness After providing the anti-reflection film, a photoresist (product name “TARF-P7145”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the anti-reflection film, heat-treated at 145 ° C. for 60 seconds, and a 180 nm-thick photoresist. A film was formed. The photoresist film thus obtained was exposed through a mask pattern with a 130 nm diameter contact hole using an exposure apparatus (product name “Nikon NSR-S302A” manufactured by Nikon Corporation), and then 110 ° C. For 60 seconds. On the other hand, lauryldimethylamine oxide (RDMAO) and didecylmethylamine oxide (DDMAO) were dissolved in deionized water with the composition shown in Table 4 to prepare a resist surface modifier. Then, the prepared resist surface modifier was dropped on the photoresist film, and the contact angle of the resist surface modifier was measured. The results are shown in Table 4.

[0058] [Table 4]

[0059] From the results of Table 4, the resist surface modifiers of Examples 3 to 5 containing lauryldimethylamine oxide and didecylmethylamine oxide contained V, N! /, And an amine oxide compound. It was confirmed that the contact angle with respect to the photoresist film was smaller than that of the resist surface modifier of Comparative Example 2. Therefore, it is considered that the resist surface modifiers of Examples 3 to 5 efficiently spread over the photoresist film surface.

[0060] [Evaluation of wettability of photoresist film after surface modification to deionized water]

A coating solution for forming an anti-reflective coating (product name “ARC-29A” manufactured by Brewer) was applied on an 8-inch silicon wafer and heat-treated at 215 ° C. for 60 seconds to obtain a film thickness of 77 nm. After providing the antireflection film, a photoresist (product name “TARF-P7145”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the antireflection film, and heat-treated at 145 ° C. for 60 seconds to form a 180 nm thick photoresist. A resist film was formed. The photoresist film thus obtained was exposed through a mask pattern with a 130 nm diameter contact hole using an exposure apparatus (product name “Nikon NSR-S302A” manufactured by Nikon Corporation), and then 110 ° C. For 60 seconds. On the other hand, lauryl dimethylamine oxide (RDMAO) and didecylmethylamine oxide (DDMAO) were dissolved in deionized water with the composition shown in Table 5 to prepare a resist surface modifier. Then, the silicon wafer was immersed in the prepared resist surface modifier for 60 seconds and then dried. Thereafter, deionized water was dropped on the photoresist film, and the contact angle of deionized water was measured. The results are shown in Table 5.

[Table 5]

[0062] From the results shown in Table 5, the photoresist films treated with the resist surface modifiers of Examples 3 to 5 containing lauryldimethylamine oxide and didecylmethylamine oxide contained an ammine oxide compound. ! /, NA! / It was confirmed that the contact angle of deionized water was smaller than that of the photoresist film treated with the resist surface modifier of Comparative Example 2. Therefore, it is considered that the developer reaches the surface of the photoresist film efficiently by treating the photoresist film with the resist surface modifier of Examples 3 to 5.

[0063] [Evaluation of developability after surface modification with resist surface modifier]

Apply an anti-reflective coating solution (product name "ARC-29A", manufactured by Brewer) on 8 inch silicon wafer, heat treatment at 215 ° C for 60 seconds, and reflect with 77nm thickness After providing the anti-reflection film, a photoresist (product name “TARF-P7145”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the anti-reflection film, heat-treated at 145 ° C. for 60 seconds, and a 180 nm-thick photoresist. A film was formed. An exposure apparatus (Nico Product name “Nikon NSR-S302A”), and exposed through a mask pattern with a contact hole of 130 nm in diameter, followed by heat treatment at 110 ° C. for 60 seconds. On the other hand, lauryl dimethylamine oxide (RDMAO) and didecylmethylamine oxide (DDMAO) were dissolved in deionized water at the composition shown in Table 6 to prepare a resist surface modifier. The prepared resist surface modifier was applied to the surface of the photoresist film at 2000 rpm for 7 seconds and then dried. Thereafter, by 60 seconds development processing at 23 ° C using a 2-38 mass ^_0/0 tetramethylammonium Niu arm hydroxide aqueous solution to form a resist pattern of 130nm contact hole. The repelling of the developer at this time was visually observed. The pattern shape was observed with a scanning electron microscope and evaluated as ◯ when a good resist pattern was formed and X when a resist pattern defect that was thought to be caused by development failure was observed. The results are shown in Table 6.

[Table 6]

[0065] From the results shown in Table 6, the photoresist film treated with the resist surface modifiers of Examples 3 to 5 containing lauryldimethylamine oxide and didecylmethylamine oxide contained an amine compound. ! /, NA! / Compared with the photoresist film treated with the resist surface modifier of Comparative Example 2, no repelling of the developer was observed, and it was confirmed that a good resist pattern was formed.

[0066] (Examples 6 to 8, Comparative Example 3)

[Evaluation of wettability of photoresist film to resist surface modifier]

Apply an anti-reflective coating solution (product name "ARC-29A", manufactured by Brewer) on 8 inch silicon wafer, heat treatment at 215 ° C for 60 seconds, and reflect with 77nm thickness After providing the anti-reflection film, a photoresist (product name “TARF-P7145”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the anti-reflection film, and heat-treated at 145 ° C. for 60 seconds to form a 180 nm thick photoresist. A resist film was formed. The photoresist film thus obtained was exposed through a mask pattern with a 130 nm diameter contact hole using an exposure apparatus (product name “Nikon NSR-S302A” manufactured by Nikon Corporation), and then 110 ° C. For 60 seconds. On the other hand, lauryl dimethylamine oxide (RDMAO) (Nippon Yushi Co., Ltd., trade name “UNIsafe A-LM”) and alkyl sulfonate trimethylamine salt (ASTMA) (ASTMA) (Takemoto Yushi Co., Ltd.) with an average carbon number of 15 are removed A resist surface modifier was prepared by dissolving in ion water with the composition shown in Table 7. The prepared resist surface modifier was dropped on the photoresist film, and the contact angle of the resist surface modifier was measured. The results are shown in Table 7.

[Table 7]

[0068] From the results shown in Table 7, the resist surface modifiers of Examples 6 to 8 containing lauryl dimethylamine oxide and alkylsulfonate trimethylamine salt were compared to those of Comparative Examples 3 and 6 that contained no! / It was confirmed that the contact angle to the photoresist film was smaller than that of the resist surface modifier. Therefore, it can be considered that the resist surface modifiers of Examples 6 to 8 efficiently spread over the photoresist film surface.

[0069] [Evaluation of wettability of photoresist film after surface modification to deionized water]

Apply an anti-reflective coating solution (product name "ARC-29A", manufactured by Brewer) on 8 inch silicon wafer, heat treatment at 215 ° C for 60 seconds, and reflect with 77nm thickness After providing the anti-reflection film, a photoresist (product name “TARF-P7145”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the anti-reflection film, heat-treated at 145 ° C. for 60 seconds, and a 180 nm-thick photoresist. A film was formed. The photoresist film thus obtained was exposed through a mask pattern with a 130 nm diameter contact hole using an exposure apparatus (product name “Nikon NSR-S302A” manufactured by Nikon Corporation), and then 110 ° C. For 60 seconds. On the other hand, Lauryldimethylamine Oxide (RDMAO) (manufactured by NOF Corporation, trade name “UNISafe A—LM”) ) And an alkyl sulfonate trimethylamine salt having an average carbon number of 15 (ASTMA) (manufactured by Takemoto Yushi Co., Ltd.) were dissolved in deionized water with the composition shown in Table 8 to prepare a resist surface modifier. Then, the silicon wafer was immersed in the prepared resist surface modifier for 60 seconds and then dried. Thereafter, deionized water was dropped on the photoresist film, and the contact angle of deionized water was measured. The results are shown in Table 8.

[Table 8]

[0071] From the results in Table 8, the photoresist films treated with the resist surface modifiers of Examples 6 to 8 containing lauryl dimethylamine oxide and alkyl sulfonate trimethylamine salt contained the! / And deviations. As a result, it was confirmed that the contact angle of deionized water was smaller than that of the photoresist film treated with the resist surface modifier of Comparative Example 3. Therefore, it is considered that the developer reaches the surface of the photoresist film efficiently by treating the photoresist film with the resist surface modifiers of Examples 6 to 8.

[0072] [Developability evaluation after surface modification with resist surface modifier]

Apply an anti-reflective coating solution (product name "ARC-29A", manufactured by Brewer) on 8 inch silicon wafer, heat treatment at 215 ° C for 60 seconds, and reflect with 77nm thickness After providing the anti-reflection film, a photoresist (product name “TARF-P7145”, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the anti-reflection film, heat-treated at 145 ° C. for 60 seconds, and a 180 nm-thick photoresist. A film was formed. The photoresist film thus obtained was exposed through a mask pattern with a 130 nm diameter contact hole using an exposure apparatus (product name “Nikon NSR-S302A” manufactured by Nikon Corporation), and then 110 ° C. For 60 seconds. On the other hand, lauryl dimethylamine oxide (RDMAO) (Nippon Yushi Co., Ltd., trade name “UNIsafe A-LM”) and alkyl sulfonate trimethylamine salt (ASTMA) (ASTMA) (Takemoto Yushi Co., Ltd.) with an average carbon number of 15 are removed A resist surface modifier was prepared by dissolving in ion water with the composition shown in Table 9. And The prepared resist surface modifier was applied to the photoresist film surface at 2000 rpm for 7 seconds and then dried. Thereafter, by 60 seconds development processing at 23 ° C using a 2-38 mass ^_0/0 tetramethylammonium Niu arm hydroxide aqueous solution, to form a registry pattern of 130nm contact hole. The repelling of the developer at this time was visually observed. Moreover, the pattern shape was observed with a scanning electron microscope, and a case where a good resist pattern was formed was evaluated as ◯, and a case where a resist pattern defect that was thought to be caused by a defective image was observed as X. The results are shown in Table 9.

[Table 9]

From the results shown in Table 9, it was found that the photoresist films treated with the resist surface modifiers of Examples 6 to 8 containing lauryl dimethylamine oxide and alkyl sulfonate trimethylamine salt contained the! As compared with the photoresist film treated with the resist surface modifier of Comparative Example 3, no repelling of the developer was observed, and it was confirmed that a good resist pattern was formed.

Claims

Claims [1] A resist surface modifier having an aqueous solution strength containing at least one amine oxide compound represented by the following general formulas (1) and (2). [Chemical CnH2n + 1 R1- →-O (l) I CnH2nOH R1— O (2) I CmH2mOH

[2] The resist surface modifier according to claim 1, further comprising at least one amine oxide compound represented by the following general formulas (3) and (4).

[Chemical 2]

R ²

I

H _2n + iC _n -N— (3)

I

But

R ²

I

HOH _2n C _n -N— (4)

I

R ³

(In the formulas (3) and (4), R ² and R ³ each independently represent an alkyl group or hydroxyalkyl group having 8 to 20 carbon atoms which may be interrupted by an oxygen atom, and n represents 1 to 5 [3] At least one amine oxide compound represented by the general formulas (1) and (2) and at least one amine oxide compound represented by the general formulas (3) and (4) The resist surface modifier according to claim 2, comprising: 99:;! To 80:20 in a mass ratio.

[4] The resist surface modifier according to claim 1 or 2, which comprises 0.01 to 10% by mass of the amine oxide compound.

[5] The resist surface modifier according to claim 1 or 2, further comprising an anionic surfactant.

[6] Each of the amine oxide compound and the anionic surfactant is added in an amount of 1 mass ppm to

The resist surface modifier according to claim 5, which is contained in an amount of 1% by mass.

[7] The anionic surfactant is an alkyl group having 8 to 20 carbon atoms (including a phenyl group and an alkylene oxide group in the middle of an alkyl chain which may have a hydroxyl group or a carboxyl group). At least selected from alkyl sulfates, alkyl sulfonates, and alkyl phosphates having a straight chain or branched chain).

6. The resist surface modifier according to claim 5, wherein the resist surface modifier is one kind of neutralized salt.

8. The resist surface modifier according to claim 1, wherein the aqueous solution contains water as a solvent.

[9] The aqueous solution is a mixture of water and a water-miscible organic solvent.

1. The resist surface modifier according to 1.

10. The resist surface modifier according to claim 9, wherein the water-miscible organic solvent is a monohydric or polyhydric alcohol organic solvent.

[11] The blending amount of the water-miscible organic solvent in the solvent is 0.01 to 10% by mass.

9. The resist surface modifier according to 9.

12. The resist surface modifier according to claim 1, further comprising 1 mass 111 to 5 mass% of a compound selected from among polyoxyalkylene glycols and alkyl ethers thereof.

[13] Furthermore, 0.1 mass ppm or more; 10 mass of a soluble polymer containing a nitrogen atom in the molecular structure

The resist surface modifier according to claim 1, which comprises:

14. The resist surface modifier according to claim 1, which is used as a resist surface treatment solution before a photoresist film development step.

[15] providing a photoresist film on the substrate;

A step of selectively exposing the photoresist film through a mask pattern; a step of treating the exposed photoresist film with the resist surface modifier according to any one of claims 1 to 14; And developing the photoresist film after the treatment with the resist surface modifier.