JPH0325445A - Positive type resist composition - Google Patents

Abstract

PURPOSE:To obtain a compsn. suitable for fine etching and contg. a light absorbing material producing no effect on characteristics of a resist in practical use by incorporating alkali-soluble phenol resin and specified compds. CONSTITUTION:Alkali-soluble phenol compd., a quinonediazido compd. and a compd. represented by formula I are incorporated. In formula I, each of R<1> and R<2> is alkyl or cyanoalkyl, R<3> is H, alkyl or halogen, R<4> is H or cyano and each of R<5> and R<6> is alkoxycarbonyl or cyano but at least one of R<5> and R<6> is alkoxycarbonyl. A compsn. suitable for fine etching and contg. a light absorbing material producing no effect on such characteristics of a resist as the sensitivity, resolution, heat resistance, etching resistance and shelf life stability in practical use is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a positive resist composition, and more particularly to a semiconductor device. This invention relates to a positive resist composition for microfabrication necessary for manufacturing magnetic bubble memory devices, integrated circuits, etc.

(Conventional technology) When manufacturing semiconductors, a resist is applied to the surface of a silicon wafer to form a photoresist film, a latent image is formed by irradiation with light, and then a negative or positive image is formed by developing the latent image. Semiconductor devices are formed using lithography techniques.

Conventionally, negative resists made of cyclized polyisoprene and bisazito compounds have been known as resist compositions for forming semiconductor devices.

However, since this negative resist is developed with an organic solvent, it expands greatly and has a limited resolution, so it has the disadvantage that it cannot be used in the manufacture of highly integrated semiconductors. on the other hand,
For this negative resist composition, positive resist M
Since the i-Kaimono has excellent resolution, it is considered that it can sufficiently cope with the high integration of semiconductors.

At present, the positive type resist composition generally used in this field is composed of a novolac resin and a quinonediazide compound.

However, even with such a positive resist composition with excellent resolution, when trying to form a pattern on a substrate such as aluminum or tungsten silicide, which has a high reflectance, it is affected by the reflected light from the substrate. , it is known that the image becomes blurred and line width control becomes extremely difficult.

Such development becomes more noticeable when there are steps on the substrate.

It is known to add a light-absorbing material to solve such problems, for example, as disclosed in Japanese Patent Publication No. 51-37562.
has been disclosed. However, it is very difficult to select a light-absorbing material that does not affect other properties of the resist at all or only to a practical extent.

(Objects to be Solved by the Present Invention) It is an object of the present invention to solve the above-mentioned drawbacks of the prior art and improve sensitivity.
The object of the present invention is to provide a positive resist composition suitable for microfabrication that contains a novel light-absorbing material that does not practically affect resist properties such as resolution, heat resistance, etching resistance, and storage stability.

(Means for Solving the Problems) This object of the present invention is to obtain an alkali-soluble phenolic resin.
A positive resist Mi characterized by containing a quinonediazide compound and a compound represented by the following general formula <1)
Achieved by precepts.

Rl. R*, alkyl group or cyanoalkyl group R"; 1
{, alkyl group or halogen R'; H or cyano group R5, R6, alkoxycarbonyl group or cyano group, provided that at least one is alkoxycarbonyl base The alkali-soluble phenol resin used in the invention is, for example, a combination of phenols and aldehydes. Condensation reaction product. A condensation reaction product between phenols and ketones. Examples include vinylphenol polymers, isopropenylphenol polymers, and hydrogenation reaction products of these phenolic resins.

Here, specific examples of phenols used include phenol 1-cresol, xylenol, ethylphenol,
Probylphenol. Butylphenol. Monohydric phenols such as phenylphenol: resorcinol. Examples include polyhydric phenols such as birocatechol, hydroquinone, bisphenol A, and birogallol.

Further, specific examples of aldehydes include formaldehyde, acetaldehyde, benzaldehyde, and terephthalaldehyde.

Furthermore, specific examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, and diphenyl ketone.

These condensation reactions can be carried out according to conventional methods.

Moreover, the vinylphenol-based polymer is selected from a homopolymer of vinylphenol and a copolymer of vinylphenol and a monomer copolymerizable with vinylphenol. Specific examples of copolymerizable components include acrylic acid derivatives. Methacrylic acid derivatives, styrene derivatives, maleic anhydride. Maleic acid derivative, vinyl acetate. Examples include acrylonitrile.

Further, the isobropenylphenol-based polymer is selected from a homopolymer of isobrobenylphenol and a copolymer of hysobrobenylphenol and a copolymerizable monomer. Specific examples of copolymerizable components include acrylic acid derivatives, methacrylic acid derivatives, styrene derivatives, and maleic anhydride. Examples include maleic acid imide derivatives, vinyl acetate, and acrylonitrile.

These hydrogenation reactions of phenolic resins can be carried out by any known method, including dissolving the phenolic resin in an organic solvent and introducing hydrogen in the presence of a homogeneous or heterogeneous hydrogenation catalyst. By doing so, you can attain the precepts.

These alkali-soluble phenolic resins may be used alone, or two or more types may be used in combination.

In the positive resist composition of the present invention, for example, a copolymer of styrene and acrylic acid, methacrylic acid, or maleic anhydride may be used to improve developability, storage stability, heat resistance, etc., as necessary. , a copolymer of an alkene and maleic anhydride. Vinyl alcohol polymers, vinyl pyrrolidone polymers, rosin, Sierrac, etc. can be added. The amount added is 10% of the above alkali-soluble phenolic resin.
0 to 50 parts by weight, preferably 5 to 20 parts by weight
It is a proportion of parts by weight.

The quinonediazide compound used in the present invention is not particularly limited, but includes 1,2-penzoquinonediazide-4-sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester. Examples include 1.2-naphthoquinonediazide-5-sulfonic acid ester, 2.1-naphthoquinonediazide-4-sulfonic acid ester, 2.1-naphthoquinonediazide-5-sulfonic acid ester, and other sulfonic acid esters of quinonediazide derivatives. .

These quinonediazide sulfonic acid esters can be synthesized by an esterification reaction of a quinonediazide sulfonic acid compound, and are described in Gentaro Nagamatsu and Hideo Inui, Photosensitive Polymer J (1980) Kodansha (Tokyo), etc. It can be synthesized according to conventional methods.

These quinonediazide sulfonic acid esters may be used alone, but two or more types may be used in combination. The blending amount is 1-100 parts by weight per 100 parts by weight of the resin, preferably 3 to 40 parts by weight. If it is less than 1 part by weight, it will be impossible to form a pattern, and if it exceeds 100 parts by weight, undeveloped residue will likely occur.

The compound of general formula (1) used in the present invention is not particularly limited, but specific examples include the following.

113 The compounds represented by the general formula (1) can be used alone, or two or more kinds can be used in combination.

The compounding amount of the compound represented by the general formula (1) is as follows:
0.00 parts by weight. 2 to 15.0 parts by weight,
Preferably it is 1 to 7 parts by weight. If it is less than 0.2 parts by weight, the antireflection effect will not be sufficient, and if it exceeds 15 parts by weight, precipitation will occur, and the sensitivity will be lowered and the pattern shape will deteriorate, which is undesirable.

The positive resist Mi product of the present invention is used by dissolving it in a solvent. Examples of solvents include: 1 acetone, 1 methyl ethyl ketone, 1 cyclohexanone, cyclobentanone, cyclohexanol, etc.
alcohols such as n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, dioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc. alcohol ethers, probyl formate, butyl formate, probyl acetate, butyl acetate, methyl blobionate, ethyl probionate. Methyl butyrate, ethyl butyrate. Esters such as methyl lactate, ethyl lactate, cellosolve esters such as cellosolve acetate, methyl cellosolve acetate, ethyl cellosolve acetate, propyl cellosolve acetate, butyl cellosolve acetate, propylene glycol, propylene glycol monomethyl ether. Propylene glycols such as brobylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate-1, propylene glycol monobutyl ether, diethylene glycol 7-methyl ether, diethylene glycol 7-ethyl ether. Diethylene glycols such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, halogenated hydrocarbons such as trichloroethylene, aromatic hydrocarbons such as toluene and xylene, dimethylacetamide. Examples include polar solvents such as dimethylformamide and N-methylacetate. these are,
They may be used alone or in combination of two or more.

The positive resist composition of the present invention may optionally contain a surfactant and a storage stabilizer. Sensitizer. Compatible additives such as anti-striation agents and plasticizers can be included.

An aqueous alkaline solution is used as the developing solution for the positive resist M1 precept of the present invention. Specifically, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium diammonium silicate, ethylamine, probil Primary amines such as amines, diethylamine. Secondary amines such as dibropylamine, tertiary amines such as trimethylamine and triethylamine, and diethylethanolamine. Alcohol amines such as triethanolamine, tetramethylammonium hydroxide. Examples include quaternary ammonium salts such as tetraethylammonium hydroxide, trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, and trimethylhydroxyethylammonium hydroxide.

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

(Example) The present invention will be described in more detail with reference to Examples below.

Note that parts and percentages in the examples are based on weight unless otherwise specified.

Nopolasoc Resin 100 obtained by mixing m-cresol and p-cresol at a molar ratio of 6:4, adding formalin to this, and condensing the mixture in a conventional manner using an oxalic acid catalyst.
90% of the 2,3,4,4'-tetrahydrooxyhenzophenone is 1. 18 parts of a quinonediazide compound which is an ester of 2-naphthoquinonediazide-5-sulfonic acid. Compound (1+5 parts of ethyl cellosolve acetate 32
Dissolved in 0 parts. A resist solution was prepared using a 1 μm Teflon filter.

After applying the above resist solution onto a silicon wafer using a coater, it was betatized at 90°C for 90 seconds to a thickness of 1. l7μ
A resist film of m was formed. This wa-ti-ivA
Exposure was carried out using a Stesohar ALS-2142i (manufactured by Geoffral Signal Co., Ltd.) and a test reticle.Next, exposure was performed using a 2.38% tetramethylammonium hydroxide aqueous solution at 23°C for 1 minute.By the paddle method. I developed it and got a solid pattern.

When the patterned wafer was taken out and observed under an electron microscope, lines and spaces of 0.50 μm were resolved. The film thickness of the pattern is 1.15μ when measured using a film thickness meter Alpha Step 200 (manufactured by Tenco).
It was m.

Furthermore, the wafer with this pattern was etched using a dry etching device DEM-45 IT (manufactured by Nichiden Anelva Co., Ltd.) at a power of 300 W, a pressure of 0.03 Torr, a gas of CF4/H=3/1, and a frequency of 1. 5 6MHz
When etching was performed, it was observed that only the areas where there was no pattern were etched.

After applying the resist solution of Example 1 onto a silicon wafer using a coater, it was baked at 80° C. for 90 seconds to give a thickness of 1.5 m.
A 2 μm resist film was formed. This wafer was exposed using an i-line stepper ALS-2 1 4 2 i and a test reticle. Next, transfer this wafer to 110
FEB (POSTEXPOSURE BA) for 60 seconds at °C.
KING) After cooling at 23°C with a 2.38% aqueous tetramethylammonium hydroxide solution. 1 minute. It was developed using the paddle method to obtain a positive pattern.

When the patterned wafer was taken out and observed under an electron microscope, lines and spaces of 0.45 μm were resolved. The film thickness of the pattern was measured with a film thickness meter Alpha Step 200 and was found to be 1.12 μm.

After applying the resist solution of Example 1 with a large contact length to an aluminum evaporated substrate with a step of 1 μm, it was baked at 80° C. for 90 seconds to form a resist film. This wafer was subjected to n-light irradiation using an iNIA stepper ALS-2142t and a test reticle. Next, this wafer was heated to 110°C for 60 seconds.
After BIP EBL, development was performed using a 2.38% aqueous solution of tetramethylammonium hydroxide at 23° C. for 1 minute using the paddle method to obtain a positive pattern.

When the patterned wafer was taken out and observed under an electron microscope, lines and spaces of 0.45 μm were resolved. Further, no thinning of the pattern was observed even at the step portion, and the influence of reflected waves was sufficiently removed.

Mix m-cresol, p-cresol and 3,5-xylenol in a molar ratio of 50:20:30, add formalin to this, and condense using an oxalic acid catalyst in a conventional manner. 100 parts of the resulting novolac resin, 2.2', 4.4'
-90% of tetrahydroxybenzophenone is 1.2-
20 parts of a quinonediazide compound, which is an ester of naphthoquinonediazide-5-sulfonic acid, and 4 parts of compound {5} were dissolved in 320 parts of ethyl cellosolve acetate. lμ
A resist solution was prepared by filtering it through a Teflon filter.

This resist solution was applied to an aluminum evaporated substrate having a step of 1 μm, and then baked at 80° C. for 90 seconds to form a resist film. This wafer is transferred to i-line stepper AL.
Exposure was performed using S-2142i and a test reticle. Next, this wafer was subjected to PEBL at 110°C for 60 seconds.
After that, the film was developed using a paddle method using 1 volume of 2.38% tetramethylammonium hydroxide water at 23° C. for 1 minute to obtain a positive pattern.

When the wafer with the patterned shape was taken out and observed under an electron microscope, lines and spaces of 0.45 μm were resolved. Further, no thinning of the pattern was observed even at the step portion, and the influence of reflected waves was sufficiently removed.

Copolymer of vinyl junol and styrene (molar ratio 6:4)
MOO Department, 2, 3. 4. 18 parts of a quinonediazide compound in which 95% of 4'-tetrahydroxybenzophenone is an ester of 1,2-naphthoquinonediazide-5-sulfonic acid and 5 parts of compound (1) are dissolved in 280 parts of ethyl lactate. A resist solution was prepared by filtering through a 1 μm Teflon filter.

This resist film was coated on an aluminum vapor-deposited substrate with a step of 1 μm and then incubated at 100° C. for 90 seconds to form a resist film. This wafer is transferred to i-line stepper A.
Exposure was performed using LS-2142i and a test reticle. This wafer was then subjected to PEBI at 110°C for 60 seconds.
, and then heated with a 2.38% aqueous solution of tetramethylammonium hydroxide at 23°C for 1 minute. A positive pattern was obtained by development using the paddle method.

Take out the patterned wafer and use electronic WJi.
When observed with a mirror, lines and spaces of 0.50 μm were resolved. Further, no thinning of the pattern was observed even at the step portion, and the influence of reflected waves was sufficiently removed.

A resist was prepared by removing compound (1) from the resist of Example 1, and the same pattern as in Example 3 was formed.

When the patterned wafer was taken out and observed under an electron microscope, lines and spaces of 0.45 μrn were resolved, but the pattern was severely thinned at the stepped portions, and the influence of reflected waves was observed. .

A resist was prepared by removing the compound (5) from the resist of Example 4, and patterned in the same manner as in Example 3.

When the patterned wafer was taken out and observed under an electron microscope, it was found that lines and spaces of 0.45 μm were resolved, but the pattern was severely thinned at the stepped portions, and the influence of reflected waves was observed.

Claims (1)

[Claims] (1) A positive resist composition containing an alkali-soluble phenol resin, a quinone diazide compound, and a compound represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ R^1, R^2; Alkyl group or cyanoalkyl group R^
3; H, alkyl group or halogen R^4; H or cyano group R^5, R^6; alkoxycarbonyl group or cyano group, provided that at least one is an alkoxycarbonyl group