JPS63146029A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To obtain a positive type photosensitive composition which sensitizes by deep UV and is capable of forming of a fine resist pattern and has large allowability at the time of forming pattern by forming the titled composition from a polymer contg. a specific structural unit. CONSTITUTION:The titled composition contains the structural unit shown by formula I wherein R1-R4 may be the same or different with each other, and are each hydrogen or halogen atom, or vinyl, allyl, 1-10C an unsubstd. or a substd. alkyl group, 1-10C alkoxy group, 1-14C an unsubstd. or a substd. aryl, aryloxy, nitro, hydroxy or mercaphto group, X is alkyl or an aromatic group, etc., Y is a substituent group. Thus, the positive type photosensitive composition which sensitizes by the deep UV, and is capable of forming of the fine resist pattern and has the large allowability at the time of forming the pattern and is suitable to use for the photoetching process of a semiconductor device, etc., is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Field of Industrial Application) The present invention relates to a photosensitive composition useful for forming a fine resist pattern, and more specifically, to a positive photosensitive composition sensitive to deep UV. Involved.

(Prior Art) In the manufacturing process of semiconductor devices such as ICs, microfabrication technology using photoetching is employed.

This technology involves forming a photoresist film on a substrate such as a silicon single crystal wafer by spin coating, exposing the resist film to dccp UV through a mask with a desired pattern, and then developing it. , a resist pattern is formed by processing such as rinsing,
Furthermore, by using the resist pattern as an etching mask, the exposed wafer is etched to form lines or windows with minute widths. In such microfabrication technology,
The accuracy of semiconductor devices depends on the performance of the photoresist used,
For example, it depends on the resolution on the substrate, the precision of photoresponsiveness, the adhesion to the substrate, the resistance to etchant, etc.

By the way, as resists sensitive to deep UV, photosensitive compositions made of bisazide, a novolak resin containing azide, or vinylphenol resin have been known. Such a photosensitive composition can form a submicron resist pattern and has excellent dry etching resistance. However, the photosensitive composition is of a negative type and has large variations in pattern width during the development process, etc., requiring strict control, and has a problem of low tolerance during the pattern forming process.

(Problems to be Solved by the Invention) The present invention has been made in order to solve the above-mentioned conventional problems. The present invention aims to provide a positive-type photosensitive composition with high properties.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a photosensitive composition comprising a polymer containing a structural unit represented by the following general formula.

However, R1-R4 in the formula may be the same or different, and each represents a hydrogen atom, a halogen atom, a vinyl group, an allyl group, an unsubstituted or substituted alkyl group having 1 to 10 carbon atoms,
Alkoxy group having 1 to 10 carbon atoms, unsubstituted or substituted aryl group having 1 to 14 carbon atoms, aryloxy group, nitro group, hydroxy group, mercapton group, X is an alkyl group,
an alkyl group or an aromatic group having an aromatic group, and Y represents a substituent.

Specific examples of polymers containing the structural unit represented by the above general formula are shown below.

In addition to the above polymer, the photosensitive composition of the present invention may contain benzene derivatives, acetophenone derivatives, and anthracene derivatives as sensitizers.

Next, a process for forming a resist pattern using the photosensitive composition of the present invention will be explained.

First, a resist solution made of the photosensitive composition of the present invention dissolved in an organic solvent is applied onto a substrate by a spin coating method or a dipping method, and then dried to form a resist film.

Examples of the substrate used here include a single silicon single crystal wafer, a single silicon wafer on which various films such as an insulating film and a conductive film are deposited, or a mask blank. Examples of the organic solvent include cyclohexane,
Ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, cellosolve solvents such as methyl cellosolve, methyl cellosolve acetate, and ethyl cellosolve acetate, ester solvents such as ethyl acetate, butyl acetate, and isoamyl acetate, and mixed solvents thereof are preferred.

Next, the resist film is exposed to decp UV through a mask having a desired pattern using a mercury lamp or the like as an exposure source, and then developed with an alkaline aqueous solution.

As a result, the exposed portion of the resist film is dissolved and removed, forming a desired resist pattern. The alkaline aqueous solution used here may be any one that quickly dissolves the exposed areas of the resist film and has an extremely low dissolution rate for other non-exposed areas (e.g., tetramethylammonium hydroxide aqueous solution, Examples include organic alkali aqueous solutions such as, and inorganic alkali aqueous solutions such as potassium hydroxide and sodium hydroxide.

(Function) Since the photosensitive composition of the present invention is composed of a polymer containing a structural unit represented by the above general formula, it has photosensitivity to decpUV and can be used as a positive type resist. Furthermore, when forming a pattern using the photosensitive composition, strict control during development is not required compared to conventional photosensitive compositions, so 1, the tolerance in the pattern forming process can be increased.

(Example of the invention) Examples of the present invention will be described in detail below.

A resist solution was prepared by dissolving the polymer synthesized from Example 1 using triethylamine as a desalting agent in tetrahydrofuran. Subsequently, this resist solution was applied onto a silicon single crystal wafer using a spinner and dried to form a resist film with a thickness of 0.7 μm. A mask having a pattern with an interval of 0.5 μm was brought into contact with the resist film, and a high pressure Contact exposure was performed using a mercury lamp. Next, when the exposed resist film was developed with a tetramethylammonium aqueous solution, a resist pattern with a width of 0.5 μm faithful to the mask pattern could be formed with high precision.

A resist solution was prepared by synthesizing triethylamine as a desalting agent from Example 2 and dissolving 100 parts by weight of the polymer and 3 parts by weight in cyclohexane. Next, this resist solution was applied onto a silicon single crystal wafer using a spinner and dried to form a resist film with a thickness of 0.5 μm, and then a mask having a moon pattern was brought into contact with the resist film for 0.5 μm. Contact exposure was performed using a high-pressure mercury lamp. Next, when the exposed resist film was developed with a tetramethylammonium aqueous solution, a resist pattern with a width of 0.5 μm faithful to the mask pattern could be formed with high precision.

A resist solution was prepared by dissolving the polymer synthesized from Example 3 using triethylamine as a desalting agent in tetrahydrofuran. Subsequently, this resist solution was applied onto a silicon single crystal wafer using a spinner and dried to form a resist film with a thickness of 0.9 μm. A mask having a pattern with an interval of 0.5 μm was brought into contact with the resist film, and a high pressure Contact exposure was performed using a mercury lamp. Next, when the exposed resist film was developed with a tetramethylammonium aqueous solution, a resist I pattern with a width of 0.5 μm faithful to the mask pattern could be formed with high precision.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to form a fine resist pattern through deep UV exposure, and the tolerance during pattern formation is large, making it suitable for photoetching processes for semiconductor devices, etc. A positive photosensitive composition can be provided.

Claims (1)

[Scope of Claims] A photosensitive composition comprising a polymer containing a structural unit represented by the following general formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ However, R_1 to R_4 in the formula may be the same or different, and each represents a hydrogen atom, a halogen atom, a vinyl group, an allyl group, a non-carbon number of 1 to 10. Substituted or substituted alkyl group, alkoxy group having 1 to 10 carbon atoms, unsubstituted or substituted aryl group having 1 to 14 carbon atoms, aryloxy group, nitro group, hydroxy group, mercapton group, X is an alkyl group, aromatic group, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ An alkyl group or an aromatic group having , Y indicates a substituent.