KR980011711A - Base resin for chemically amplified resist - Google Patents

Abstract

The present invention relates to a base resin for chemically amplified resists. The polymer of the present invention has a hydrophobic group and a hydrophilic group, and has a large difference in solubility before and after exposure, and is excellent in adhesion to a film and is therefore suitable for use as a base resin for chemically amplified resists. In addition, since the kinds of the repeating units are small, the manufacturing process is simple.

Description

Base resin for chemically amplified resist

Since this is a trivial issue, I did not include the contents of the text.

More specifically, the present invention relates to a base resin for chemically amplified resists, and more particularly to a base resin for chemically amplified resists, which not only maintains transparency upon exposure with a wavelength (193 nm) of an ArF excimer laser newly used in accordance with high integration of semiconductor chips, The present invention relates to a base resin for a chemically amplified resist which has a hydrophilic group at the same time.

As the degree of integration of a semiconductor chip increases to more than 1 giga-Dram, it is required to form a subquarter-micron-level fine pattern in a lithography process. Accordingly, a lithography technique using an ArF excimer laser (193 nm) having a shorter wavelength than a conventional deep ultraviolet (UV) (248 nm) has been introduced, thereby forming a pattern of high resolution with a high sensitivity It is necessary to introduce new materials that can be used.

A chemically amplified resist is a material that can form a pattern if H ^- (proton) generated by exposure is used as a catalyst and the diffusion and decomposition reaction of H ^- occurs in a chain and maintains transparency.

Generally, a base resin and a photoacid generator (PAG) into which a dissolution inhibiting group is introduced are used as an essential constituent of a chemically amplified resist to control solubility.

Among them, the base resin is generally a copolymer, and more specifically, a hydrophilic repeating unit introduced with a hydrophobic repeating unit substituted with a dissolution inhibiting group and a substrate improves the adhesion between the substrate and the hydrophilic repeating unit It is made in an appropriate proportion. The base resin also contains a repeating unit having a bulky group introduced for the purpose of improving resistance to etching. Therefore, in order to produce a base resin for a chemically amplified resist for ArF suitable for a lithography process, generally three or more monomers are required, which is disadvantageous in terms of difficulty in manufacturing and cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a resin composition which has both a hydrophobic group and a hydrophilic group and has two types of repeating units, Type resist base resin.

In order to accomplish the above object, the present invention provides a base resin for a chemically amplified resist represented by Chemical Formula 1.

(Formula 1)

Wherein R ₁ is a methyl, ethyl, cyclohexyl or phenyl group, R ₂ is a methyl or t-butyl group, R ₃ is a hydrogen atom or a methyl group, being.

The present invention provides a resin having both hydrophilic groups in which one repeating unit functions as a dissolution inhibiting group and hydrophilic groups capable of improving the applicability of the resist by bonding with membrane quality. Hereinafter, a reaction mechanism by exposure of the polymer (I-1 of formula (II)) provided according to a preferred embodiment of the present invention is shown and will be described in more detail with reference to it.

(2)

As can be seen from the above formula (2), the polymer of the present invention has a property of not dissolving well in a developing solution before the exposure process, and has a hydroxy group. On the other hand, through the exposure process, the t-butoxycarbonyl is converted to a carboxyl group and the solubility in the developer is greatly increased.

The base resin of the present invention having such properties is produced through the following process.

First, the monomer (IV) is prepared through the following reaction.

(Formula 3)

Diazabicyclo [2,2,2] octane is added to an aldehyde and an acrylate derivative, followed by stirring. As a result, the compound of formula A monomer as shown is obtained. In this case, the acrylate derivative is preferably administered in an excess amount exceeding the equivalence ratio.

When a monomer having both a hydrophilic group and a hydrophobic group is prepared according to the above reaction, a polymer is synthesized according to the following reaction.

(Formula 4)

That is, the monomers (IV and V) represented by the general formula (4) are dissolved in an organic solvent at a predetermined molar ratio. In this case, the reaction molar ratio of the compound (IV) to the compound (V) is preferably 0.3: 0.7 to 0.7: 0.3, and 1,4-dioxane is preferable. Subsequently, a polymerization initiator is added to the reaction mixture to obtain a copolymer represented by (IV).

Hereinafter, the polymer synthesis method of the present invention will be described in more detail with reference to examples, but the present invention is not necessarily limited thereto.

Example 1

22 g (0.5 mol) of acetaldehyde and 96 g (0.75 mol) of t-butyl acrylate were placed in a flask and then 8 g (0.075 mol) of 1,4-diazabicyclo [2.2.2] And maintained at room temperature for 6 days. After completion of the reaction, the unreacted material was evaporated, dropped into a large amount of water, and neutralized with a hydrochloric acid solution. After extracting with diethyl ether (50 ml x 4), magnesium sulfate was added to the extract to remove water, and then t-butyl (1 (IV-1) -Hydroxy) ethyl acrylate (yield: 98%).

Example 2

12.0 g (0.07 mol) of the monomer prepared in Example 1 and 6.6 g (0.03 mol) of the monomer represented by the formula 6 (V-1) were dissolved in 74 ml of 1,4-dioxin. Thereto was added 0.82 g of azobisisobutyronitrile as a polymerization initiator, followed by polymerization at 70 DEG C for 24 hours to prepare the polymer (I-1 of formula (2)) of the present invention.

As can be seen from the above, the polymer produced according to the present invention has a hydrophobic group and a hydrophilic group in one repeating unit, and thus has a large difference in solubility before and after exposure and has excellent adhesion to a film. It is suitable for use. Also, there is an advantage that the number of repeating units of the polymer is small and the types of monomers used in the production thereof are small.

Claims (1)

1. A base resin for a chemically amplified resist represented by Chemical Formula (1). Wherein R ₁ is a methyl, ethyl, cyclohexyl or phenyl group, R ₂ is a methyl or t-butyl group, R ₃ is a hydrogen atom or a methyl group, being. ※ Note: It is disclosed by the contents of the first application.