JPS60138546A - Formation of resist film - Google Patents

Abstract

PURPOSE:To improve the adhesion between a resist film and a base body by treating preliminarily the surface of the base body with a specific silane coupling agent in the stage of forming the resist film consisting of a polymer of fluoroalkyl acrylate on the surface of the base body. CONSTITUTION:The surface of a base body to be formed thereon with a resist film is preliminarily treated by a method such as dipping, coating, spraying or the like using a silane coupling agent having an amino group, thiol group, vinyl group or ethylene oxide group. The embodiment of the silane coupling agent is exemplified by the silane coupling agents expressed by the formula I , the formula II, etc. The resist film consisting of the polymer expressed by the formula III(R<3> is H, methyl, ethyl, halogen, R<2> is 1-6C divalent hydrocarbon; Rf is 1-15C alkyl of which the hydrogen atom is substd. by a fluorine atom) (e.g.; the formula IV, the formula V) is then formed on the surface of the base body.

Description

DETAILED DESCRIPTION OF THE INVENTION More specifically, the present invention relates to a method for improving the adhesion between a resist film and a substrate when forming a resist film made of a fluoroalkyl acrylate polymer on the surface of the substrate.

Polymers of fluoroalkyl acrylates are useful as resist materials used in integrated circuit manufacturing, and are useful in electronic f! It is known as a resist material with excellent resolution and sensitivity to high-energy rays such as

However, when a film formed from such a resist material is formed on the surface of a certain type of substrate, in the step of developing it into a resist pattern, 1) a developer penetrates between the resist film and the substrate; Problems may arise due to poor adhesion, such as part of the resist film peeling off or rising. As a result, the dimensions of the circuit pattern on the surface of the substrate obtained by etching or the like deviate from predetermined dimensions, resulting in a decrease in precision. In some cases, such peeling or blistering cannot be recovered even by post-baking after development and before etching.

The present invention has been made in view of such conventional problems, and it is an object of the present invention to provide a method for improving the adhesion of a resist film made of a fluoroalkyl acrylate polymer to a substrate surface.

That is, the present invention provides the substrate surface with amino groups, thiol groups,
The present invention relates to a method for forming a resist film, which comprises treating the substrate surface with a silane coupling agent having a vinyl group or an ethylene oxide group to form a Ray/X)M film made of a polymer of fluoroalkyl acrylates on the surface of a substrate.

The silane coupling agent used in the present invention is a silane coupling agent having an amino group, a thiol group, a vinyl group, or an ethylene oxide group. Since the above-mentioned groups are present in the silane coupling agent, the adhesion between the substrate surface and the resist film made of the fluoroalkyl acrylate polymer is improved. Among these silane coupling agents, preferred are those in which at least one of the hydrogen atoms bonded to the silicon atom of silane, silthian, or si-tetraxane is a Nl2(OH2)n- group, a Nl2(
CH2) mNl ((OH2)11 group, NH20CM(
(OH2), - group, HS(CH2), n- group, OH2
= OH- group or 10\OH2- (!H(OH2)mO(C!H2), substituted with one group, where m and n are each an integer from 1 to 5, and one force is at least 1 hydrogen atoms are substituted with an alkoxy group having 1 to 5 carbon atoms, a methoxyalkoxy group having 2 to 6 carbon atoms, or a chlorine atom, and the remaining hydrogen atoms are substituted with an alkyl group having 1 to 5 carbon atoms or a hydroxyl group. I can give you what you don't have.

Specific examples of these include NH203H6Si(002H5)3, plate 2C curved surface C
Chi6s1(ooH3)3・NH200BIH03H6S
i(002H5)3, HSO3H6Si(OGH3)
3, OH2 = col(ooH3)3, The substrate surface can be treated with these silane coupling agents by dissolving the silane coupling agent in an appropriate solvent and applying, dipping, spraying or spraying.

This can be done by various coating methods such as noting. Furthermore, if the coupling agent is a liquid, it can be used as is. The remaining liquid on the treated surface is volatilized or washed away with a solvent and then subjected to the next resist film formation step, at a temperature of 70 to 150°C.
Prebaking is preferred.

When a film of various fluoroalkyl acrylate polymers is formed on a substrate whose surface has been surface-treated with a coupling agent in this way using a conventional method, its adhesion is comparable to that of a substrate whose surface has not been surface-treated. As the polymer of fluoroalkyl acrylates used in the present invention, for example, the polymer having the general formula (■) 20H2=O(R
1) COOR2Rf (■) (wherein R is a methyl group, an ethyl group, or a group in which at least one of their hydrogen atoms is substituted with a halogen atom, a halogen atom or a hydrogen atom, and R2 is a carbon number of 1 to 2) homologous polymers of fluoroalkyl acrylates or the fluoroalkyl acrylates represented by a valent hydrocarbon group (Rf is an alkyl group having 1 to 15 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom) Examples include copolymers with one or more other vinyl monomers.

Specific examples of the fluoroalkyl acrylates represented by the general formula (I) include OH2=0(OH3)OOOOOH2(OF2)2HC
! H2 = 0(OH3)0000(OH3)2(OF2
)2HOH2= 0(OH3)000CH20HFOF
30H2=0(OH3)0000H20F20HFO
F30H2= 0(OH3)0000H(OH3)OF
20HFOF3OH2= O(OH3)OOOOOH(O
pH)15)OF20HFO]! '30H2=a(
oH3) aooaa (o3a7)ah2amay30H
2=0(OH3)0000H(OH3)20F20H
FOIP30H2=0(OH3)0000(OH3)
(02H5)OF20)IIFIOF3, etc.

Examples of vinyl thread monomers other than fluoroalkyl acrylates include ethylenically unsaturated olefins such as ethylene, butypyrene, butylene, isobutylene, and butadiene; styrenes such as styrene, α-methylstyrene, and p-chlorostyrene. unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid/maleic anhydride; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate,
Dodecyl acrylate, n-octyl acrylate, Aku1
] Esters of α-methylene aliphatic monocarboxylic acids such as 2-chloroethyl chlorate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and ethyl α-ethyl acrylate; Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; salts (vinyl esters such as vinyl, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate; 1)
- Ethylene derivatives such as methyl-1-methoxyethylene, 1.1-dimethoxyethylene, 1,2-dimethoxyethylene, 1.1'-dimethoxycarbonylethylene, 1-methyl-1'-ditroethylene; N- Vinylpyrrole, N-vinyl compound Kuzol\N-vinylindole,
N-vinyl compounds such as N-vinylpyrrolidone and N-vinylpyrrolidone; also acrylonitrile, methacrylamide, methacrylamide, α-ethylacrylamide, acrylate, p
-Chloroacrylanilide, m-nitroacrylanilide, m-methoxyacrylanilide, vinylidene chloride, vinylidene cyanide, glycidyl acrylate, glycidyl acrylate, alkyl-α-cyanoacrylate, alkyl-α-cyanomethacrylate, etc. .

Vinyl monomers other than fluoroalkyl acrylates are preferably used in an amount that does not exceed 30 mol% in the copolymer, that is, the amount of fluoroalkyl acrylates is at least 70 mol%. , the amount of the vinyl spinning wheel b1° in the copolymer is 10 mol%
It is more preferable to use it in the range of more than 7 (I,).

Among the vinyl monomers, preferable examples include acrylic acid, methacrylic acid, methyl acrylate,
Ethyl acrylate, ethyl methacrylate, ethyl methacrylate, ac 1-noramide-methacrylamide, α-ethylac 1-noramide, glycidyl acrylate, glycidyl methacrylate, methyl-α-cyanoacrylate 1-ethyl-α-cyanoacrylate, methyl-α-cyano Examples include methacrylate, ethyl a-cyano methacrylate, and the like.

These preferred copolymers of vinyl monomers and fluoroalkyl acrylates have excellent adhesion to the substrate surface by themselves, and the higher the proportion of the vinyl yarn monomer, the better the adhesion to the substrate surface. However, the sensitivity and resolution of the resist film tend to decrease. Within the above ratio range, sensitivity and resolution are good, and adhesion is also good. By treating the surface of the substrate with a silane coupling agent in advance as in the present invention, adhesion can be further improved, and therefore a fine resist pattern can be formed more accurately.

The substrate used in the present invention is not particularly limited, but specifically, for example, a chromium masked substrate, a substrate formed from silicon, silicon oxide, silicon oxide, silicon titanium, aluminum, titanium, gold, etc. Regardless of which method is used, the method of the present invention can improve the adhesion between the substrate and the resist film.

Next, the method of the present invention will be explained in more detail with reference to Reference Examples and Examples, but the present invention is not limited to these Examples.

Reference Example 1 99 parts of 2,2.3.4.4.4-hexafluorobutyl methacrylate (hereinafter referred to as HFBMA) (mold recess,
Glycidyl methacrylate (hereinafter referred to as GMA)
), 1 part azobisisobutyronitrile (hereinafter referred to as A
7) and 150 parts of methyl isobutyl ketone were added and mixed, frozen and degassed.
Copolymerization was carried out for 24 hours at o0C.

Acetone was added to the reaction mixture to make a homogeneous solution, and then petroleum ether was added to precipitate it, resulting in copolymer 51.
I got a department.

The obtained copolymer was made into a methyl ethyl ketone solution. The intrinsic viscosity [η] of the solution measured at 35qO is 1, o6az
/p was 0, and the weight average molecular weight determined by gel permeation chromatography was approximately i, 200.0
It was 00.

Reference Examples 2 to 4 Methacrylic acid (Reference Example 2), Methac IJ instead of GMA
The conditions for the copolymerization reaction were adjusted to the first
A copolymer was obtained in the same manner as in Reference Example 1 except that the materials were replaced with those shown in the table.

Table 1 shows the yield of the obtained copolymer, the intrinsic viscosity [η] determined in the same manner as in Reference Example 1, and the weight average molecular weight.

Table 1 Example 1 γ-Aminopropyltriethoxysilane was used as a silane coupling agent, and a mixed solvent consisting of 5 parts of water and 90 parts of ethanol was added to 5 parts of γ-aminopropyltriethoxysilane to dissolve it. The obtained silane coupling agent solution was applied onto a silicone sea urchin, and after being left for 5 minutes, it was spin-coated at 2000 rpm for 1 minute. Next, this was prebaked at 80°C for 10 minutes and then allowed to cool.

An 8% by weight methyl isobutyl ketone solution of the copolymer obtained in Reference Example 1 was placed on the surface of a silicon wafer treated with a silane coupling agent as described above, and the solution was heated at 2000 rpm.
The resist film was spin-coated at a temperature of m for 1 minute and prebaked at a temperature of 140° for 30 minutes to form a resist film of about 0.4 μm.

In order to examine the adhesion between the obtained resist film and the substrate (silicon wafer), the following adhesion test was conducted. - (Adhesion test)] Using 1+RID-502 type electron beam lithography equipment (Elionix formal dress), accelerating voltage 2okv (current density 1 x 10
I
Irradiate at
The film was then developed with a mixture of methyl isobutyl ketone and isobutetrapanol (volume ratio 1.5:98.5), further washed with isopropanol, and finally dried.

The thus obtained resist pattern E was observed under an optical microscope with a magnification of 400 times to examine its adhesion. The results are shown in Table 2.0 The criteria for evaluating adhesion are as follows.

×: Peeling was observed in any part of the resist pattern.

△: At least a small amount of resist pattern sticking was observed.

○: In both cases, the resist pattern was observed to be completely adhered.

Examples 2 to 7 Experiments were conducted in the same manner as in Example 1, except that the silane coupling agent solution, copolymer, developing solution, and cleaning solution used were replaced with those shown in Table 2. Table 2 shows the adhesion of each resist film obtained.

Claims (1)

[Scope of Claims] 1. Treating the surface of a substrate with a silane coupling agent having an amino group, a thiol group, a vinyl group, or an ethylene oxide group to form a resinate coating made of a polymer of fluoroalkyl acrylates on the surface of the substrate. Method 0 for forming a resist film characterized by
2), Nu(OH2)n-group, Nu20(IIH(O
H2)n-group, H8(CH2)n-group, OH2=OH
- group or 10, OH2-aH(aH2)n1o(ca2- group (in the formula,
m and n are each an integer of 1 to 5), and at least one alkoxy group has 1 to 5 carbon atoms,
Claims that are substituted with a methoxyalfoxy group having 2 to 6 carbon atoms or a chlorine atom, and the remaining hydrogen atoms are substituted or unsubstituted with an alkyl group or hydroxyl group having 1 to 5 carbon atoms. The method described in paragraph 1. 3 The silane coupling agent is NH2C3H6S1 (OC
2H5) 3\N1202H4NHO details 6s1 (o plate 3)
3. Recommended 200 dishes Ochiro 5t (OC2H5) 3. H3O3
H6Si(OCH3)3.01(2=0H8i(OC
H3)3, cH2=0H8i(002H5)3. 4 The polymer of fluoroalkyl acrylates has the general formula (I): aH2=0(R1)OOOR2Rf(I) (in the formula R
1 is a methyl group, an ethyl group, or a group in which at least one of their hydrogen atoms is substituted with a halogen atom, a halogen atom or a hydrogen atom, R is a divalent hydrocarbon group having 1 to 6 carbon atoms, and Rf is at least 1 is an alkyl group having 1 to 15 carbon atoms, in which 5 hydrogen atoms are substituted with fluorine atoms.
The method according to claim 1, wherein the copolymer contains mol %.