JPH04269754A - Positive type photosensitive resin composition and photosensitive element using same - Google Patents

Abstract

PURPOSE:To obtain a positive type photosensitive resin compsn. having high photosensitivity, good stability and wide developing allowance by incorporating a specified compd. into the molecule. CONSTITUTION:The molecule of the compsn. contains a compd. having tert-amyl ester structure of carboxylic acid and a compd. which produces oxygen by irradiation of active ray. Further, it is preferable that the compd. having tert- amyl ester structure of carboxylic acid in the molecule is a copolymer obtd. by copolymn. of tert-amyl acrylate and/or tert-amyl methacrylate as the essential component. The compd. which produces oxygen by irradiation of active ray is expressed by formula I and/or formula II, wherein R is an alkyl group.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is a positive photosensitive material that can form fine resist patterns used in the manufacture of semiconductor devices, magnetic valve memories, electronic components such as printed wiring board integrated circuits, and planographic printing plates. The present invention relates to a resin composition and a photosensitive element using the same.

0002

2. Description of the Related Art Conventionally, orthoquinonediazide compounds have been mainly used as photosensitive materials for forming positive resist patterns used in the manufacture of electronic components, lithographic printing plates, and the like. However, orthoquinonediazide compounds have the disadvantage of low photosensitivity because their quantum yield is at most 1 and sensitization is difficult. In addition, since the exposure wavelength is fixed, a problem has arisen in that it cannot keep up with the shortening of the exposure wavelength aimed at improving the resolution of photoresist.

0003

[Problem to be solved by the invention] In recent years, with the main purpose of increasing sensitivity and resolution, compounds that generate acid when irradiated with light undergo a reaction such as decomposition with the acid, and become solubilized in a developer. Positive-type photosensitive systems that are combined with chemical compounds are attracting attention. Examples of this include a combination of a compound that generates an acid upon irradiation with light and an acetal compound (Japanese Patent Application Laid-Open No. 48-89003), and a combination of a polymer having an acetal or ketal group in the main chain (Japanese Patent Application Laid-Open No. 53-133429). tert-butyl ester of carboxylic acid or phenol. Combination with a polymer having a tert-butyl carbonate group (Japanese Patent Publication No. 2-2766)
0), etc. However, these
They were not necessarily fully satisfactory in terms of photosensitivity, stability, development latitude, etc.

In view of the above problems, the present invention has high photosensitivity,
The object of the present invention is to provide a positive photosensitive resin composition with good stability and a wide development latitude, and a photosensitive element using the same.

[0005]

[Means for Solving the Problems] The present invention provides a positive photosensitive resin composition comprising a compound having a tert-amyl ester structure of carboxylic acid in its molecule and a compound that generates an acid upon irradiation with actinic rays. and a photosensitive element using the same.

According to the present invention, carboxylic acid tert-
The amyl ester structure has high solubility in general-purpose organic solvents and good compatibility with other resins, and has other effects other than those mentioned above.

The present invention will be explained in detail below. Compounds having a carboxylic acid tert-amyl ester structure in one molecule include one or more carboxylic acid tert-amyl ester structures in one molecule.
There is no particular restriction as long as the compound has an rt-amyl ester structure, but if the compound is a low molecular compound, for example,

[
Chemical 3]

[C4]

[C5]

[C6]

[C7] In addition, in the case of polymer compounds,

00
08]

Examples include copolymers obtained by copolymerizing monomers such as [Image Omitted] as essential components. Among these, homopolymers of tert-amyl acrylate and tert-amyl methacrylate, or copolymers with other copolymerizable monomers are preferred.

Other copolymerizable monomers mentioned here include, for example, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, cyclohexyl methacrylate, cyclohexyl acrylate,
2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, acrylonitrile, styrene, α
-Methylstyrene, diacetone acrylamide, vinyltoluene, etc., and one or more of these can be used in combination for copolymerization. The amount of copolymerization of these other copolymerizable monomers is the total amount of all monomers constituting the copolymer.
Of the 00 parts by weight, it is preferably 80 parts by weight or less. If it exceeds 80 parts by weight, photosensitivity tends to decrease.

The copolymer is synthesized by general solution polymerization of the polymerizable monomer in an organic solvent using a polymerization initiator such as azobisisobutyronitrile, azobisdimethylvaleronitrile, or benzoyl peroxide. Obtainable. Examples of organic solvents used at this time include methoxyethanol, ethoxyethanol, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanol, butyl acetate, chlorobenzene, and dioxane. The weight average molecular weight (in terms of polystyrene) of the copolymer is preferably in the range of 5,000 to 150,000. If it is less than 5,000, the mechanical strength of the resist tends to be weak, and if it exceeds 150,000, the viscosity of the solution increases, making it difficult to obtain a thin and uniform coating (photosensitive film).

When a low-molecular compound is used as the compound having a carboxylic acid tert-amyl ester structure in its molecule, it is preferable to use a binder together from the viewpoint of film-forming properties. Examples of binders include polymers soluble in water or aqueous bases, such as phenol novolac resins, cresol novolak resins, melamine-formaldehyde resins, polyethylene oxide, polyacrylamide, poly-p-vinylphenol, polymethacrylic acid, and polyacrylic acid. can be given. The amount of these binders used is preferably 80 parts by weight or less based on 100 parts by weight of the total amount of the compound (low molecular weight compound) having a tert-amyl ester structure of carboxylic acid in the molecule and the binder. If it exceeds 80 parts by weight, photosensitivity tends to decrease.

[0012] As a binder, carboxylic acid te is used in the molecule.
It is preferable to use a copolymer (high molecular compound) obtained by copolymerizing a monomer having an rt-amyl ester structure as an essential component. In other words, there is a carboxylic acid ter in the molecule.
As the compound having a t-amyl ester structure, it is preferable to use the low-molecular compound and the high-molecular compound together. In this case, the amount of the binder (high molecular compound) used may exceed 80 parts by weight based on 100 parts by weight of the total amount of the low molecular compound and the high molecular compound.

On the other hand, as a compound having a tert-amyl ester structure of carboxylic acid in the molecule, a copolymer (high molecular compound) is prepared by copolymerizing a monomer having a tert-amyl ester structure of carboxylic acid in the molecule as an essential component. The aforementioned water- or aqueous base-soluble polymer may be used in an amount of 50 parts by weight or less out of a total of 100 parts by weight of the polymer and the polymer. If it exceeds 50 parts by weight, compatibility may decrease.

The amount of the compound having a carboxylic acid tert-amyl ester structure in the molecule is the total amount of the compound having a carboxylic acid tert-amyl ester structure in the molecule and the compound that generates an acid upon irradiation with actinic rays. 10
0 parts by weight, preferably 50 to 99.5 parts by weight, and 70 parts by weight.
~98 parts by weight is more preferred. If it is less than 50 parts by weight, the content of the compound that generates acid upon irradiation with actinic rays is too high, and stability tends to decrease, and if it exceeds 99.5 parts by weight, photosensitivity tends to decrease.

Next, typical examples of compounds that generate acid upon irradiation with actinic rays are as follows:

Oxadiazole derivatives substituted with trihalomethyl groups such as [Chemical 9],

[0016]

s-triazine derivatives substituted with trihalomethyl groups such as

[0017]

[Chemical formula 11] Iodonium salts, such as

[0018]

[Chemical formula 12] sulfonium salts, such as

[0019]

[Chemical formula 13] Examples include imidosulfonate derivatives such as.

Among these, the following general formula (I) or (I
The nitrobenzyl derivative represented by I) is

[Chemical formula 14] (In the formula, R represents an alkyl group)

embedded image (wherein R represents an alkyl group) is preferred. Typical examples of these compounds are:

[Chemical formula 16]

[Chemical formula 17]

[Chemical formula 18]

[Chemical formula 19] Examples include.

The amount of the compound that generates an acid upon irradiation with actinic rays is 100 parts by weight in total of the compound having a tert-amyl ester structure of carboxylic acid in the molecule and the compound that generates an acid upon irradiation with actinic rays. 0.
It is preferably 5 to 50 parts by weight, particularly preferably 2 to 30 parts by weight. If it is less than 0.5 parts by weight, photosensitivity tends to decrease, while if it exceeds 50 parts by weight, stability tends to decrease.

A sensitizer may also be added to the positive photosensitive resin composition of the present invention. Examples of the sensitizer include perylene, pyrene, anthracene, thioxanthone, Michler's ketone, benzophenone, 9-fluorenone, and anthrone. The range is preferably 1 to 100 parts by weight, particularly 5 to 100 parts by weight.
More preferably 50 parts by weight. If it is less than 1 part by weight, the sensitizing effect tends to be low, and if it exceeds 100 parts by weight, the sensitizer tends to be insoluble or precipitated.

The positive photosensitive resin composition of the present invention may further contain dyes, pigments, plasticizers, surface smoothing agents, adhesion promoters, inorganic fillers, etc. as appropriate.

The positive photosensitive resin composition of the present invention is usually prepared by preparing a solution in which the above-mentioned components are dissolved in an organic solvent, and the solution is applied onto a substrate and dried to form a photosensitive film. Thereafter, the resist pattern is formed by irradiating actinic light in an imagewise manner, preferably performing post-heating, and then removing the exposed areas with a developer.

Examples of the organic solvent for dissolving the positive photosensitive resin composition of the present invention include methyl ethyl ketone, dioxane, cyclohexanone, toluene, methoxypropylene glycol, ethyl lactate, 1-methoxy-2-propylacetate, ethylene dichloride, Examples include butyl acetate. These organic solvents may be used alone or in combination of two or more. Generally, 1 to 5 of the positive photosensitive resin composition of the present invention is added to these organic solvents.
It is used by dissolving 0% by weight. If it is less than 1% by weight, it will be difficult to form a uniform photoresist film, and if it exceeds 50% by weight, it will be difficult to form a thin photoresist film.

Substrates on which a photosensitive film is formed using this solution include metal plates such as aluminum, zinc, and iron, plastic films such as polyethylene, polycarbonate, cellulose nitrate, and polyvinyl acetal, and metal foils, although they vary depending on the purpose. Laminate or metal-deposited plastic film or paper, other copper-clad laminates,
Representative examples include silicon wafers and silicon dioxide wafers.

Methods for applying a solution of the positive photosensitive resin composition onto these substrates include spin coating, spraying, solution casting, dip coating, and the like. The photosensitive film may be formed directly on the base material to be used in this way, or a solution of a positive photosensitive resin composition may be applied on a support such as a polyester film in advance and dried to laminate the film. If necessary, a protective film such as a polyolefin film is further laminated to form a photosensitive element, and if a protective film is used, it is peeled off and laminated onto the desired base material to achieve the desired effect. A photosensitive film may be formed on the surface of the substrate. The thickness of the photoresist film varies depending on the application, but is usually in the range of 0.1 to 100 μm.

Examples of the light source for actinic rays that imagewise irradiate the obtained photosensitive film (usually through a support when a photosensitive element is used) include a mercury lamp, a xenon lamp, a metal halide lamp, and a chemical lamp. High-density energy beams such as lamps, carbon arc lamps, g-lines, i-lines, deep-UV light, and even helium-neon lasers, argon lasers, krypton ion lasers, helium-cadmium lasers, and KrF excimer lasers can be used. can. After irradiation with actinic rays, ter
60-1 to promote the decomposition of the t-amyl ester.
It is preferable to post-heat in the range of 60°C for 0.5 to 30 minutes.

Development of the positive photosensitive resin composition of the present invention (
When a photosensitive element is used, the developer used (after removing the support) may be an inorganic alkali such as sodium metasilicate, sodium carbonate, sodium hydroxide or potassium hydroxide, or an organic alkali such as a tetraalkylammonium salt. Aqueous alkaline solutions are preferred. The concentration of the alkaline aqueous solution is preferably 0.1 to 15% by weight, and 0.5 to 15% by weight.
5% by weight is more preferred. If it is less than 0.1% by weight, the exposed area may not be completely removed in a short time;
If the amount exceeds % by weight, there is a possibility that unexposed areas may also be partially attacked. The developing method is carried out by spraying the above-mentioned developer or by immersing the film in the developer.

[0030]

[Examples] The present invention will be explained below with reference to Examples. Example 1 Cresol novolac resin (meta/para ratio = 40/60
(weight ratio), Mw=8,000) 10 g, 4 g of terephthalic acid di-tert-amyl ester, the general formula (I
), R is ethyl, p-nitrobenzyl derivative 0.2
A solution containing 100 g of dioxane and 100 g of dioxane was applied onto a silicon wafer using a spin coater, and dried at 100° C. for 15 minutes to obtain a photoresist film with a thickness of 2 μm. A 3KW ultra-high pressure mercury lamp was applied to the surface of this photoresist film through a photomask at 100mJ/
After exposure to a light amount of cm2, heating at 140° C. for 5 minutes, and spray development with a 1% by weight sodium metasilicate aqueous solution, a good resist pattern with a resolution of 3 μm was formed.

Example 2 120 g of dioxane was added to a flask equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel, and a nitrogen gas introduction tube, and the mixture was stirred and heated to 90° C. while blowing nitrogen gas. When the temperature became constant at 90°C, a mixture of 90 g of tert-amyl methacrylate and 0.9 g of azobisisobutyronitrile was dropped into the flask over 2 hours, and then kept at 90°C for 3 hours with stirring. . 3
After an hour, a solution prepared by dissolving 0.4 g of azobisdimethylvaleronitrile in 20 g of dioxane was dropped into the flask over 10 minutes, and then kept at 90° C. for 4 hours while stirring. The homopolymer of tert-amyl methacrylate thus obtained (weight average molecular weight 34,000
) solution 26g (polymer solid content 10g), general formula (I)
A solution containing 1 g of a p-nitrobenzyl derivative in which R is butyl and 80 g of methyl ethyl ketone was applied onto a silicon wafer using a spin coater and dried at 100° C. for 15 minutes to obtain a photoresist film with a thickness of 2 μm. A 3KW ultra-high pressure mercury lamp was applied to the surface of this photoresist film through a fat mask at a rate of 70mJ/
After exposure to a light amount of cm2, heating at 130° C. for 10 minutes, and spray development with a 1% by weight sodium metasilicate aqueous solution, a good resist pattern with a resolution of 2 μm was formed.

Example 3 120 g of propylene glycol monomethyl ether was added to a flask equipped with the same equipment as in Example 2, stirred, and heated to 90° C. while blowing nitrogen gas. When the temperature became constant at 90°C, a mixture of 60 g of tert-amyl acrylate, 40 g of methyl methacrylate, and 1 g of azobisisobutyronitrile was dropped into the flask over 2 hours, and then stirred at 90°C for 3 hours. I kept it warm. After 3 hours, a solution prepared by dissolving 0.5 g of azobisdimethylvaleronitrile in 20 g of propylene glycol monomethyl ether was added dropwise into the flask over 10 minutes, and then kept at 90° C. for 4 hours while stirring. 24 g (polymer solid content: 10 g) of the thus obtained copolymer solution of tert-amyl acrylate (weight average molecular weight 39,000), p-nitrobenzyl derivative in which R in general formula (I) is butyl 1. A solution containing 5 g and 80 g of a mixed solvent of methyl ethyl ketone/dioxane = 1/1 (weight ratio) was applied onto a silicon wafer using a spin coater, dried at 100°C for 15 minutes, and a film thickness of 4 μm was obtained.
A photoresist film of m was obtained. The surface of this photoresist film was exposed to light of 200 mJ/cm2 using a 3KW ultra-high pressure mercury lamp through a photomask, and then heated at 120°C for 15 minutes.
As a result of spray development with a 1% by weight sodium metasilicate aqueous solution, a good resist pattern with a resolution of 10 μm was formed.

Example 4 21 g of the polymer solution obtained in Example 2 (polymer solid content 8
g), terephthalic acid di-tert-amyl ester 2
g, 0.5 g of p-nitrobenzyl derivative in which R in general formula (I) is methyl, 2-(p-methoxystyryl)-4
．． 6-bis(trichloromethyl)-s-triazine 0.
A solution containing 3 g and 100 g of dioxane was applied onto a silicon wafer using a spin coater and dried at 100° C. for 15 minutes to obtain a photoresist film with a thickness of 0.5 μm. A 3KW ultra-high pressure mercury lamp was applied to the surface of this photoresist film for 60m through a photomask.
After exposure to a light amount of J/cm2, heating at 140° C. for 3 minutes, and spray development with a 1% by weight aqueous sodium carbonate solution, a good resist pattern with a resolution of 1 μm was formed.

[0034]

Effects of the Invention The positive photosensitive resin composition of the present invention and the photosensitive element using the same have advantages such as high photosensitivity, good stability and development latitude, and due to these advantages, A high-resolution resist pattern can be obtained.

Claims (4)

[Claims] 1. A positive photosensitive resin composition comprising a compound having a carboxylic acid tert-amyl ester structure in its molecule and a compound that generates an acid upon irradiation with actinic rays. 2. The positive compound according to claim 1, wherein the compound having a tert-amyl ester structure of carboxylic acid in the molecule is a copolymer obtained by copolymerizing tert-amyl acrylate and/or tert-amyl methacrylate as an essential component. type photosensitive resin composition. 3. The positive photosensitive resin composition according to claim 1, wherein the compound that generates an acid upon irradiation with actinic rays is represented by the following general formula (I) and/or (II). [Formula 1] (In the formula, R represents an alkyl group) [Formula 2] (In the formula, R represents an alkyl group) 4. A photosensitive element obtained by laminating the positive photosensitive resin composition according to claim 1, 2 or 3 on a support.