JPH01126643A - Pattern forming material - Google Patents

Abstract

PURPOSE:To obtain the title material effective in the minute working of a substrate plate 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 the same or the different with each other and are each alkyl or aryl group, etc. Monomers capable of giving the structural units shown by formulas I and II are exemplified by o- hydroxystyrene or vinyltrimethylsilane, 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 plate having the stage difference, and having the excellent durability against the RIE of the oxygen gas, is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Application of Togami The present invention relates to a positive pattern forming material, and in detail,
It relates to fine pattern forming materials necessary for manufacturing semiconductor devices, magnetic bubble memory devices, integrated circuits, etc.

(Prior Art) Photolithography is used as an important means in the production of semiconductor devices, magnetic bubble memory devices, etc. In 2007 otolithography, light diffraction,
It is known that when the resist film is thick, the resolution decreases due to the effects of reflection from the substrate, etc. However, in order to obtain a high-resolution pattern, the resist film thickness is made thinner. There is a problem that the resistance of the resist becomes insufficient in the post-process. Furthermore, the substrate surface to be processed by photolithography is not necessarily flat;
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 by Bell (B.
) Research Institute Jisoo. J, M, Maram
In the @three-layer resist process proposed by et al., the lower layer is an organic polymer film that can be removed by oxygen RIB (reactive ion etching), and the middle layer is an oxygen RIB such as polysilicon or silicon dioxide. A resist film is formed on the inorganic film that is difficult to remove, and a pattern is formed on the upper layer.The upper resist film is irradiated with the desired pattern, and then the desired pattern is obtained.Next, using this upper layer as a mask, the inorganic Transfer the pattern to the intermediate layer of the film by dry etching @Finally, use the intermediate layer pattern as a mask,
The pattern is transferred to the underlying organic polymer film by oxygen RXH, forming a thick organic polymer film pattern.

As described above, the three-layer structure resist has difficult problems, such as the complicated process and the need to make the inorganic film that is the intermediate layer thin and form it in a way that prevents pinholes from forming.

(Problems to be Solved by the Invention) It is an object of the present invention to solve the above-mentioned drawbacks of the prior art, to be effective in microfabrication of substrates having steps, and to provide oxygen RIE.
It is an object of the present invention to provide a positive pattern forming material particularly suitable for use in a two-layer resist process, which has the roles of an upper layer and an intermediate layer in the above-mentioned three-layer resist process.

(Means for Solving the Problems) This object of the present invention is to provide 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 by the forming material.

General formula (I) (In the formula, 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 (2) % formula% (in the formula, R4, R11, H@ are the same or different, an alkyl group, an aryl group, an alkylsiloxy group, an alkoxy group,
The monomer providing the structural unit of the general formula (I) used in the present invention (which is an aralkyl group or an alkenyl group) is not particularly limited, but specific examples include O-hydroxystyrene, O-hydroxystyrene, p-hydroxystyrene, α-methyl-O-hydroxystyrene,
α-methyl-1-hydroxystyrene, α-methyl-p
-Hydroxystyrene, 3-chloro-4-hydroxystyrene, 5-dichloro-4-hydroxystyrene, 5
-promo 4-hydroxystyrene, 45-dibromo-
4-hydroxystyrene, α-methyl-3-chloro-4
-Hydroxystyrene, α-methyl-3,5-dichloro-4-hydroxystyrene, α-methyl-3-promo-4-hydroxystyrene, α-methyl-4s-dibromo-4-hydroxystyrene, 4-chloro-3- Hydroxystyrene, 4-7'romo-3-hydroxystyrene, 3-ethyl-4-hydroxystyrene, 3-furopyl-4-hydroxystyrene, 3-t-butyl-4-hydroxystyrene, 5-diethyl-4-hydroxystyrene, 5.5--) furopyru-4-hydroxystyrene,
Melon 5-di-t-butyl-4-hydroxystyrene, α-methyl-3-ethyl-4-hydroxystyrene, α-methyl-5-furopyl-4-:)'roxystyrene, α-methyl-5-t-butyl- 4-hydroxystyrene, α-methyl-45-diethyl-4-hydroxystyrene, α-
Methyl-45-digloby-4-human a-xystyrene,
α-Methyl-4s-';'tButyl-4-hydroxystyrene, 3-phenyl-4-hydroxystyrene, 3-
7-thi-4-hydroxystyrene, 3-benzyl-4
-Hydroxystyrene, 3-styryl-4-hydroxys f7. S, 5-dibenzyl-4-hydroxystyrene, 45-distyryl-4-hydroxystyrene, α-
Methyl-3-benzyl-4-hydroxystyrene, α-
Methyl-5-styryl-4-hydroxystyrene, α-
methyl-45-dibenzyl-4-hydroxystyrene,
α-Methyl-45-distyryl-4-hydroxystyrene, 3-vinyl-4-hydroxystyrene, s-propenyl-4-hydroxystyrene, 4-vinyl-3-hydroxystyrene, 4-propenyl-3-hydroxystyrene, etc. can be mentioned.

The monomer providing the structural unit of Ichimonana (■) used in the present invention is not particularly limited, but specific examples include vinyltrimethylsilane, vinyltrimethylsilane,
Vinyltripropyl 72, vinyltributylsilane,
Vinylmethyldiethylsilane, vinyldimethylethylsilane, vinylmethyldipropylsilane, vinyldimethylethylsilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriphenylsilane, vinyldimethylphenylsilane,
Vinyldiethylphenylsilane, vinylmethyldiphenylsilane, vinylethyldiphenylsilane, vinyldiethylnaphthylsilane, vinyldiethylnaphthylsilane,
Vinyltribenzylsilane, vinyldimethylbenzylsilane, vinyltriphenethylsilane, vinyldimethylethylsilane, dimethyldivinylsilane, diethyldivinylsilane, vinyldimethylpropenylsilane, vinyldimethylpropenylsilane, vinyltrimethylsiloxydimethylsilane, vinyltriethylsiloxydimethylsilane, Vinyltriethylsiloxydimethylsilane, Vinyltriethylsiloxydiethylsilane, Bis(trimethylsiloxy)methylvinylsilane, Bis(trimethylsiloxy)ethylvinylsilane, Bis(triethylsiloxy)methylvinylsilane, Bis(triethylsiloxy)ethylvinylsilane, Tris(trimethylsiloxy)vinylsilane , tris(triethylsiloxy)vinyl 72, etc.@ The polymer used in the present invention is a copolymer of monomers giving the above-mentioned maximum (I) and (10) and - maximum (I), @ and Selected from copolymers with copolymerizable monomers.If the monomer is copolymerizable, 41
Specific examples include, but are not limited to, acrylic acid, acrylic acid derivatives such as methyl acrylate, ethyl acrylate, glycidyl acrylate, and propyl acrylate; methacrylic acid, methyl methacrylate, ethyl methacrylate, and methacrylic acid. Methacrylic acid derivatives such as glycidyl, propyl methacrylate, and hydroxyethyl methacrylate; Styrene derivatives such as styrene, α-methylstyrene, p-methylstyrene, chlorstyrene, and chloromethylstyrene; and maleic anhydride derivatives and N-substituted maleimides. derivatives, vinyl acetate, vinyl pyridine, acrylonitrile, etc. The copolymerization ratio in the copolymer is usually 0 to 30% by weight. The content of 81 in the polymer is usually 5% by weight or more, preferably 10% by weight. If the weight is less than 05 weight, which is more than 0.05 weight, the oxygen RIIC resistance is insufficient.

The quinonediazide compound used in the present invention is not particularly limited, but includes, for example, 1,2-benzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester, t2-naphthoquinonediazide-4-sulfonic acid ester, Quinonediazide-5-sulfonic acid ester, 2.
Examples include 1-naphthoquinonediazide-4-sulfonic acid ester, 2.1-naphthoquinonediazide-5-sulfonic acid ester, etc. These exemplified quinonediazide compounds are described in "Photoresist J" by DeForest, 50. 1975) McCraw-Hill Inc., New York) (
D@-Forest l”photor@5tstJ
+ 51L (1975)e MeGrow-Bxz1
Engineering 116. e (N@wYOrk).

Gentabe Nagamatsu, Hideo Inui, “Photosensitive Polymer J, 117° (1
980), Kodansha (Tokyo), etc.

The 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 superpolymer. Less than 10 parts by weight,
It becomes impossible to form a pattern, and if the amount exceeds 100 parts by weight, the sensitivity decreases significantly and development residues tend to occur in exposed areas. Examples of solvents include ketones such as acetone, methyl ethyl ketone, and cyclohexanone, glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, cellosolve esters such as methyl cellosolve acetate and ethyl cellosolve acetate, toluene, Aromatic hydrocarbons such as xylene,
Examples include 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,
Surfactants, storage stabilizers, sensitizers, anti-striation agents, etc. may also be added.

An aqueous alkali solution is used as a developer for the pattern forming material of the present invention, and specific examples of alkalis include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium silicate, and ammonia, and ethylamine and propylamine. Primary amines, tertiary amines such as diethylamine and dipropylamine, tertiary amines such as trimethylamine and triethylamine, alcohol amines such as diethylethanolamine and triethanolamine, tetramethylammonium hydroxide, trimethyl hytomixethyl Examples include quaternary ammonium salts such as ammonium hydroxide and tetraethylammonium hydroxide.Additionally, if necessary, methanol,
Appropriate amounts of water-soluble organic solvents such as ethanol, furopanol, and ethylene glycol, surfactants, and resin dissolution inhibitors can be added.

(Effects of the Invention) Thus, according to the present invention, it is possible to obtain a pattern forming material that is effective in microfabrication of substrates having steps and has excellent resistance to oxygen RIE, compared to the conventional technology. Examples) The present invention will be described in more detail with reference to Examples below. Note that parts and weights in Examples are based on weight unless otherwise specified.

Example 1 25 f of p-hydroxystyrene, 25 f of vinyltrimethylsilane and 50 f of dioxane were charged into a polymerization reactor, mixed well, degassed under reduced pressure, and 20 f of a dioxane solution of azobisisobutyronitrile was added.Next, polymerization was carried out. The can was heated to 70°C and polymerization was carried out for 25 hours.The polymerization solution after the completion of polymerization was poured into methanol/water (1/7) to precipitate the polymer.◎The obtained polymer was dioxane The polymer was dissolved in water and poured into methanol/water to precipitate the polymer. Furthermore, this polymer was dissolved in dioxane, and 3
Freeze-drying was carried out for 6 hours to obtain a dry polymer. Yield is 80
%.

Gel permeability chromatograph 2 of the above polymer (
As a result of GPC) measurement, Takumi-6700, as a result of fluorescence X-ray analysis, the silicon content was 15%.O 100 parts of the above resin, 7 (1 In the above, 30 parts of a quinonediazide compound, which is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid, was mixed with 5 parts of ethyl cellosolve acetate.
90 First, a commercially available positive photoresist AZ-1550J (
Silapray) was coated on a silicon wafer with a spinner, then baked at 200°C for 30 minutes to a thickness of 1.5 μm.
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-050, T was formed, and then baked at 85°C for 30 minutes to form a 0.6 μm thick resist. An upper resist layer was formed, and a wafer for exposure was prepared.

This exposure wafer was manufactured using FPA-1550 (Canon Inc. M
) Exposure using a stepper and test reticle, and exposing to light using a tetramethylammonium hydroxide aqueous solution at 23°C.
The upper resist film was developed by a dipping method for 1 minute to obtain a positive pattern.

Using this upper layer resist as a mask, oxygen RIB (pressure 2×10″″3″f:orr,
The pattern was transferred to the lower layer film using oxygen flow rate of 208 CCM, power of 400 W, R7 frequency of 13.56 MHg, and electrode temperature of 10° C.). When the wafer 1- on which the pattern was formed was taken out and inspected with an optical microscope, the test no. The lower film that was not covered by the upper layer that formed the turns was completely removed. Example 2: Example using P-hydroxystyrene and tris(trimethylsiloxy)vinylsilane. Polymerize in the same manner as 1, and 4
590 polymer was obtained. As a result of GPC measurement of the above polymer,
MY-8500, as a result of fluorescent X-ray analysis, the silicon content was 14% 〇 100 parts of the above resin, 2.3.4
-) 27 parts of a quinonediazide compound in which 901 or more of the 10H groups of lyhydroxypenzophenone are esters of 1,2-7toquinonediazido-5-sulfonic acid, 0.1 part of a fluorine-based surfactant, and ethyl When patterning was carried out under the same conditions as in Example 1 except for using cellosolve acetate dissolved in 450 parts, the film thickness of the part covered by the upper layer on which the test pattern was formed was 1.8 μm or more, A pattern that faithfully reflects the test pattern of the reticle can be formed.90 Example 3 α-methyl-p-hydroxystyrene and vinyltriethylsilane were polymerized in the same manner as in Example 1 to obtain a 3890 polymer. 〇 As a result of GPC measurement of the above polymer, MY -
5600, results of fluorescence X-ray analysis.

As a result, the silicon content was 131s.The above polymer 1
00 parts, 27 parts of a quinonediazide compound in which 70% or more of the 10H groups of 2.5.4.4'-tetrahydroxybenzophenone are esters of 1,2-7toquinonediazido-4-sulfonic acid were converted into ethyl cellosolve acetate. 43
When patterning was carried out under the same conditions as in Example 1, using a material dissolved in 0 parts of xylene and 20 parts of xylene, the film thickness of the part where the test pattern was formed and covered with the Kujo layer was 1.7μ or more. 90 Example 4 5-t': jfk-4-hydroxystyrene and vinyltrimethylsilane were polymerized in the same manner as in Example 1.
A polymer of f was obtained @ As a result of GPC measurement of the above polymer, M
Y-7700, as a result of fluorescence X-ray analysis, the silicon content was found to be 8.100 parts of the above resin, 80% or more of the 10H groups of 2.44.4'-tetrahydroxybenzophenone were 1 .30 parts of a quinonediazide compound which is an ester of 2-su7toquinonediazide-5-sulfonic acid, 0 fluorine surfactant
．． 2 parts of the solution was dissolved in 450 parts of ethylcetate and filtered through a 0.1 μm Teflon filter to prepare a resist solution.

The resist solution was applied onto a silicon wafer using a spinner, and then baked at 80° C. for 50 minutes to form a resist film with a thickness of 1 μm, which was used as a wafer for exposure.

This exposure wafer was exposed using an FPA-1550 stepper and a test reticle, and exposed at 23°C with an aqueous solution of trimethylhydroxyethylammonium hydroxylate.
The resist film was developed by dipping for 1 minute, and rinsed with ion-exchanged water for 30 seconds to obtain a positive pattern. - Scanning electron microscope, 78M-TM01 (manufactured by JEOL Ltd.)
When the resolution i was investigated, it was found that the resolution was good up to 0.9 μ#Il.

The wafer on which this pattern was formed was etched by oxygen RIE using a dry etching device ILD-4013T, and as a result, the remaining film rate was 7Qfi.

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 an alkyl group, an aryl group, an alkylsiloxy group, an alkoxy group, an aralkyl group, or an alkenyl group)