JPH01126642A - Pattern forming material - Google Patents

Abstract

PURPOSE:To obtain the title material effective in the minute working of a substrate having especially stage difference, and having the durability against the RIE of an oxygen gas by incorporating a polymer having a specified structural unit and a quinone diazide compd. in said material. CONSTITUTION:The pattern forming material contains the polymer having the structural unit shown by formula I and II, and the quinone diazide compd. In formula I, R<1> is hydrogen atom or alkyl group, R<2> and R<3> are each hydrogen atom or alkyl group, etc. In formula II, R<4>-R<6> are each alkyl or alkylsiloxy group, and at least one of groups R<4>-R<6> is alkylsiloxy group, (n) is 0-4. Monomers capable of giving the structural units shown by formulas I and II are exemplified by o-hydroxystyrene or trimethylsiloxy dimethylsilyl methacrylate, etc. The usable polymer is selected from the group comprising the copolymer of the monomers shown by formulas I and II or the copolymer of said monomers and a monomer capable of copolymerizing with said monomers. Thus, the pattern forming material effective in the minute working of the substrate having the stage difference, and having the excellent durability against the RIE of the oxygen gas, is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a positive pattern forming material, and in detail:
Semiconductor device, magnetic bubble memory device.

It relates to fine pattern forming materials necessary for manufacturing integrated circuits and the like.

(Prior Art) Photolithography is used as an important means in manufacturing semiconductor devices, magnetic bubble memory devices, and the like. In photolithography, light diffraction,
It is known that resolution decreases when the resist film is thick due to effects such as reflection from the substrate. Therefore, if the thickness of the resist is reduced in order to obtain a high-resolution pattern, there is a problem that the resistance of the resist becomes insufficient in subsequent steps. Furthermore, the surface of the substrate processed by photolithography is not necessarily smooth;
Since the film often has various uneven steps, a sufficient film thickness is required to cover these steps.

It is difficult to satisfy these conflicting demands with a single-layer resist process, and in order to solve this problem, a pattern forming method using a three-layer resist has been developed.
) Research Institute Joo. M, Moran (J.

M, Moran) et al. In the three-layer resist process, the lower layer is an organic polymer film that can be removed by oxygen RXW (reactive ion etching), and the middle layer is an oxygen R process such as polysilicon or silicon dioxide.
This forms an inorganic film that is difficult to remove, and a resist film that forms a pattern on top.

A desired pattern is irradiated onto the upper resist film, and the desired pattern is obtained. Next, use this upper layer as a mask,
The pattern is transferred to the intermediate layer of the inorganic film by dry etching. Finally, using the intermediate layer pattern as a mask, the oxygen R
The pattern is transferred to the underlying organic polymer film using the process KIC to form a thick organic polymer film pattern. As described above, three-layer structure resists have difficult problems, such as complicated processes and the need to form the intermediate inorganic film to be thin and prevent pinholes from forming.

(Problem that the invention attempts to solve) The object of the present invention is to solve the above-mentioned drawbacks of the prior art.

Positive pattern formation that is particularly effective for microfabrication of substrates with steps and particularly suitable for use in a two-layer resist process that functions as the upper layer and middle layer of the three-layer resist process, which exhibits resistance to oxygen R process KK. The purpose is to provide materials.

(Means for Solving the Problems) This object of the present invention is to form a pattern characterized by containing a polymer having structural units represented by general formula (I) and general formula (2) and a quinonediazide compound. This is achieved through materials.

General formula (I) (wherein R1 is hydrogen or an alkyl group, and R2 and R3 are the same or different and are hydrogen, an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a halogen group) General formula (II) ( In the formula, n4. R11 and R6 are the same or different and are selected from an alkyl group and an alkylsiloxy group, and at least one is an alkylsiloxy group. n = 0 @ 1 *
2 *3 or 4) The monomer providing the structural unit of general formula (I) used in the present invention is not particularly limited, but specific examples include 0-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, -Hydroxystyrene.

α-methyl-〇-hydroxystyrene, α-methyl-m
-Hydroxystyrene, α-methyl-p-hydroxystyrene, 3-chloro-4-hydroxystyrene, 45-
Dichloro-4-hydroxystyrene, 3-bromo-4-
Hydroxystyrene.

'S, 5-Schiff' lomo 4-hydroxystyrene, α-
Methyl-3-chloro-4-hydroxystyrene.

α-Methyl-s,s-cyclo-4-hydroxystyrene, α-methyl-3-promo-4-hydroxystyrene, α-methyl-3,5-dibromo-4-hydroxystyrene, 4-chloro-5-hydroxystyrene , 4-7'
Romo 3-hydroxystyrene, 3-ethyl-4-hydroxystyrene, 5-propyl-4-hydroxystyrene, 5-t7” thyl-4-hydroxystyrene, 3.5
-diethyl-4-hydroxystyrene, 3. s-Shifcopyru-4-hydroxystyrene, 5,5-di-t-butyl-
4-hydroxystyrene, α-methyl-3-ethyl-4
-Hydroxystyrene, α-methyl-3-propyl-4
-Hydroxystyrene, α-methyl-37t7'thyl-
4-hydroxystyrene, α-methyl-45-diethyl-4-hydroxystyrene.

α-Methyl-5,5-dipropyl-4-hydroxystyrene, α-methyl-&5-dipropyl-4-hydroΦ
Cystyrene, 3-phenyl-4-hydroxystyrene,
'5-Naphthyl-4-hydroxystyrene, 3-benzyl-4-hydroxystyrene.

3-styryl-4-hydroxystyrene, 5. s-dibenzyl-4-hydroxystyrene, 5. s-distyryl-4-hydroxystyrene, α-methyl-3-benzyl-4-hydroxystyrene, α-methyl-3-styryl-4-hydroxystyrene.

α-Methyl-4s-dibenzyl-4-hydroxystyrene, α-methyl-45-distyryl-4-hydroxystyrene, 3-vinyl-4-hydroxystyrene, 5-1
0benyl-4-hydroxystyrene, 4-vinyl-3-
Hydroxystyrene.

Examples include 4-propenyl-3-hydroxystyrene and nato.

The monomer providing the structural unit of Ichimonana 〇 used in the present invention is not particularly limited, but specific examples include triethylsiloxydimethylsilyl methacrylate, triethylsiloxydimethylsilyl methacrylate,
1-()listylsiloxydimethylsilyl)methyl methacrylate.

1-()ethylsiloxydimethylsilyl)methyl methacrylate, 2-()listylsiloxydimethylsilyl)ethyl methacrylate, 2-(triethylsiloxydimethylsilyl)ethyl methacrylate, 5-(trimethylsiloxydimethylsilyl)propyl methacrylate) ,
3-(triethylsiloxydimethylsilyl)propyl methacrylate, 4-()listylsiloxydimethylsilyl)butyl methacrylate, 4-()ethylsiloxydimethylsilyl)butyl methacrylate, 1-[bis(
trimethylsiloxy)methylsilylcomethyl methacrylate, 1-[bis(triethylsiloxy)methylsilylcomethyl methacrylate.

2-[bis(trimethylsiloxy)methylsilyl]ethyl methacrylate, 5. (bis(trimethylsiloxy)
Methylsilyl] flobylme/riIJL/-), 4-(bis(trimethylsiloxy)methylsilylcobutyl methacrylate, tris(trimethylsiloxy)silyl methacrylate, tris(triethylsiloxy)silyl methacrylate, 1-[tris(trimethylsiloxy)silylcobutyl methacrylate) Methyl methacrylate, 1-()lis(triethylsiloxy)silylcomethylmethacrylate), 2-()lis(trimethylsiloxy)silyl]ethylmethacrylate)
, 2-[)lis(triethylsiloxy)silyl]ethyl methacrylate, 5-[)lis(trimethylsiloxy)
silyl]propyl methacrylate, 5-()lis(triethylsiloxy)silyl]propyl methacrylate, 4
-()lis(trimethylsiloxy)silylcobutyl methacrylate), 4-[)lis(triethylsiloxy)silylcobutyl methacrylate, and the like.

The polymer used in the present invention has the above-mentioned maximum (I)
and ■ a copolymer of monomers giving -maximum (I), ■
There are no particular limitations on the copolymerizable monomer selected from copolymers with copolymerizable monomers, but specific examples include acrylic acid, methyl acrylate,
Acrylic acid derivatives such as ethyl acrylate, glycidyl acrylate, propyl acrylate; Methacrylic acid derivatives such as methacrylic acid, methyl methacrylate, ethyl methacrylate, glycidyl methacrylate, propyl methacrylate, methacrylic acid and droxyethyl; styrene, α-
Methylstyrene, p-methylstyrene.

Styrene derivatives such as chlorstyrene and chloromethylstyrene; other examples include maleic anhydride derivatives, N-substituted maleimide derivatives, vinyl acetate, vinylpyridine, and acrylonitrile. The copolymerization ratio is usually 1 to 50% by weight in the copolymer.

The content of 81 in the polymer is usually 5% by weight or more.

Preferably it is 10 weight coefficient or more. If the weight is less than 5,
Oxygen RIE resistance is insufficient.

The quinonediazide compound used in the present invention is.

Although not particularly limited, examples include t2-penzoquinonediazide-4-sulfonic acid ester, t2-naphthoquinonediazide-4-sulfonic acid ester,
Examples include 2-naphthoquinonediazide-5-sulfonic acid ester, zl-naphthoquinonediazide-4-sulfonic acid ester, and 2.1-naphthoquinonediazide-5-sulfonic acid ester.

These exemplified quinonediazide compounds are described in DeForest, Photoresist J, 50. (I975) McGraw-Hill, Inc., New York) (D
o-Forest rPhotoresist J,
50.

(I975), McGrow-H1ll engineer,
, (New York).

Gentabu Nagamatsu, Hideo Inui, “Photosensitive Polymer J, 117° (I
980), Kodansha (Tokyo), etc.

The blending amount of these quinonediazide compounds is 10 to 100 parts by weight, preferably 20 to 70 parts by weight, based on 100 parts by weight of the above polymer.

If it is less than 10 parts by weight, it will be impossible to form a pattern.
If it exceeds 100 parts by weight, the sensitivity will be significantly lowered and the exposed areas will be more likely to be left behind.

The pattern forming material of the present invention is used by dissolving the above polymer and quinonediazide compound in a solvent.

Solvents include acetone and methyl ethyl ketone.

Ketones such as cyclohexanone, glycol ethers such as ethylene glycol monoethyl ether, and ethylene glycol monoethyl ether.

Examples include cellosolve esters such as methyl cellosolve acetate and ethyl cellosolve acetate, aromatic hydrocarbons such as toluene and xylene, and esters such as ethyl acetate and butyl acetate. These may be used alone, but two or more types may be used in combination.

Furthermore, the pattern forming material of the present invention may contain, if necessary,
A surfactant, a storage stabilizer, a sensitizer, a striation inhibitor, and the like may also be added.

As the developer for the pattern forming material of the present invention, an alkaline aqueous solution is used, specifically, sodium hydroxide, potassium hydroxide, and sodium silicate.

Inorganic alkalis such as ammonia, ethylamine.

Primary amines such as propylamine, diethylamine,
Secondary amines such as dipropylamine, tertiary amines such as trimethylamine and triethylamine, alcohol amines such as diethylethanolamine and triethanolamine, tetramethylammonium hydroxide,
Examples include quaternary ammonium salts such as trimethylhydroxyethylammonium hydroxide and tetraethylammonium hydroxide.

Furthermore, if necessary, add methanol or
Appropriate amounts of water-soluble organic solvents such as ethanol, glopanol, and ethylene glycol, surfactants, and resin dissolution inhibitors can be added.

(Effects of the Invention) Thus, according to the present invention, it is more effective in microfabrication of a substrate having a one-step difference than in the prior art, and the oxygen RIKK
A pattern-forming material with excellent durability can be obtained.

(Example) The present invention will be described in more detail with reference to Examples below. In addition, the parts and sections in Examples are based on weight unless otherwise specified.

Example 1 p-hydroxystyrene 25) and 5-[tris(trimethylsiloxy)silyl]propyl methacrylate 25) in a polymerization mill. and dioxane 5oPi, mix well,
Degassing was carried out under reduced pressure, and 1,201 liters of azobisisobutyronitrile dissolved in dioxane was added. Next, one polymerization can was heated to 170C, and polymerization was carried out for 25 hours. Polymerization solution after completion of polymerization.

The mixture was poured into methanol/water (I/7) to precipitate a polymer. The obtained polymer was dissolved in dioxane and poured into methanol/water to precipitate one polymer. Furthermore, this polymer was dissolved in dioxane and freeze-dried for 36 hours to obtain a dry polymer. The yield was 804.

Gel permeation chromatography of the above polymer (
Gpc) measurement result 1Mw=6700. As a result of fluorescence X-ray analysis, the silicon content was 15.

100 parts of the above polymer, 30 parts of a quinonediazide compound in which 70 or more of the 1011I groups of 2.44-trihydroxybenzophenone are esters of t2-naphthoquinonediazide-5-sulfonic acid are dissolved in 500 parts of ethyl cellosolve acetate, It was filtered through an 11 μm Teflon filter (manufactured by Millibore) to prepare an upper layer resist solution.

First, commercially available positive photoresist AZ-1550J (
Silapray Co., Ltd.) was applied onto a silicon wafer using a spinner, and then baked at 200C for 30 minutes.

A lower layer film having a thickness of 1.5 μm was formed. Next, the above resist for the upper layer was applied with a spinner onto the silicon wafer on which the lower layer film of AZ-1550J was formed, and then it was coated with a spinner at 85C for 30 minutes.
Bake for minutes to form an upper resist layer with a thickness of 16 μm,
This was used as a wafer for exposure.

This exposure wafer was exposed using an FPA-1550 (manufactured by Canon) stepper and a test reticle, and was exposed to light using a 23C1 aqueous solution of tetramethylanthonium hydroxide.
The upper resist film was exposed by dipping for 1 minute to obtain a positive pattern.

Using this upper layer resist as a mask, an oxygen RIB (pressure 2 x 10-” Torr, oxygen flow rate 20800M, power 400W, R7 frequency 1&56M
The pattern was transferred to the lower layer film at an electrode temperature of 10 C)K.

When the patterned wafer was taken out and inspected under an optical microscope, it was found that the lower layer that was not covered by the upper layer on which the test pattern was formed had been completely removed. The film thickness of the portion covered by the upper layer on which the test pattern was formed was measured using a film thickness meter Alpha Step-200 (manufactured by 7-Ncor Co., Ltd.).

It was possible to form a pattern that faithfully reflected the reticle test pattern with a reticle of 1.7 μm or more.

Example 2 p-hydroxystyrene and 5-()limethylsiloxydimethylsilyl)propyl methacrylate were polymerized in the same manner as in Example 1, and 40? Obtained a combination of weight and weight.

As a result of GPC measurement of the above polymer, Mw=5600°, and as a result of fluorescent X-ray analysis, the silicon content was 15%.

100 parts of the above polymer, 27 parts of a quinonediazide compound in which 90 or more sounds of the 10H group of 2.44-) lyhydroxypenzophenone is an ester of 12-nafdoquinonediazide-5-sulfonic acid, fluorine-based surfactant Buttering was carried out under the same conditions as in Example 1, except that 0.1 part of the agent was dissolved in 450 parts of ethyl cellosolve acede.

The film thickness of the portion covered by the upper layer on which the test pattern was formed was 1.6 μm or more, and it was possible to form a pattern that faithfully reflected the test pattern of the reticle.

Example 3 α-Methyl-p-hydroxystyrene and 3-[tris(
Trimethylsiloxy)silyl]propyl methacrylate was polymerized in the same manner as in Example 1 to obtain a 52F polymer.

As a result of GPO measurement of the above polymer, Mw=4600°, and as a result of fluorescent X-ray analysis, the silicon content was 154.

100 parts of the above polymer, 27 parts of a quinonediazide compound in which 70 or more sounds of the 10H group of 2.44.4'-tetrahydroxybenzophenone is an ester of 12-naphthoquinonediazide-4-sulfonic acid, 430 parts of methyl cellosolve acetate, Using a solution dissolved in 20 parts of xylene,
When buttering was performed under the same conditions as in Example 1, the film thickness of the part covered by the upper layer on which the test pattern was formed was 1.7 μm or more, and a pattern that faithfully reflected the test pattern of the reticle was obtained. was able to form.

Example 4 s-t-f thyl-4-hydroxystyrene and 3-(trimethylsiloxydimethylsilyl)propyl methacrylate were polymerized in the same manner as in Example 1 to give 30? A polymer was obtained.

As a result of GPC measurement of the above polymer, Mw=6300°, and as a result of fluorescent X-ray analysis, the silicon content was 84.

100 parts of the above polymer; 2. & 80% or more of the 10H groups in 4,4'-tetrahydroxybenzophenone.

30 parts of a quinonediazide compound which is an ester of t2-naphthoquinonediazide-5-sulfonic acid.

A resist solution was prepared by dissolving 40 parts of polyhydroxybenzylsiloxane and 12 parts of a fluorine-based surfactant in 450 parts of ethyl cellosolve acetate and filtering through a Teflon filter (I1 μm).

The above resist solution was coated on a silicon wafer with varnish, and then beta-baked at 80C for 30 minutes.

A resist film with a thickness of 1 μm was formed to prepare a wafer for exposure.

This wafer for exposure was
and a test reticle, and exposed with a trimethylhydroxyethylammonium hydroxide aqueous solution,
C. The above resist film was exposed by dipping for 1 minute and rinsed with ion-exchanged water for 30 seconds to obtain a positive pattern. Scanning electron microscope JsM-T33o (JEOL Ltd. 11
) When the strength was examined by I/C, it was found that resolution down to 19 μm was good.

The patterned wafer was etched by oxygen RIB using a dry etching device ILD-4015'r, and the remaining film ratio was 70.
・Patent applicant Zeon Corporation

Claims (1)

[Scope of Claims] A pattern-forming material characterized by containing a polymer having structural units represented by general formula (I) and general formula (II) and a quinonediazide compound. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R^1 is hydrogen or an alkyl group, R^2, R
^3 are the same or different and are hydrogen, an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a halogen group) ▲There are numerical formulas, chemical formulas, tables, etc.▼(II) (In the formula, R^4, R^5, R^6 are the same or different and are selected from alkyl groups and alkylsiloxy groups, and at least one is an alkylsiloxy group. n = 0, 1, 2, 3 or 4)