JPS63146038A - Photosensitive composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition composed of a polysilane or a polysiloxane type polymer capable of forming a fine resist pattern by incorporating a specific polymer to the titled composition, thereby dissolving fully said composition in an alkaline solution, after photodecomposition by exposing it. CONSTITUTION:The titled composition is composed of the polymer having a structural unit shown by formula I or II wherein R1-R4 and R14-R17 may be the same or different with each other, and are each hydrogen atom, 1-10C an aliphatic group, 6-14C an unsubstd. or a substd. aromatic group, R5-R8 may be the same or different with each other and are each hydrogen atom, hydroxyl, alkoxy, 1-10C an aliphatic, 6-14C an unsatd. or a satd. aromatic group, R9-R13 may be the same or different with each other, and are each hydrogen or halogen atom, 1-12C alkyl group, 1-12C alkoxy group, cyano, nitro or hydroxy group, (m) is a positive integer, (n) is a positive integer, including zero. Thus, the component soluble to an alkaline solution is formed by decomposing the irradiated part of the titled composition by irradiating an energy ray such as a UV ray, a visible ray, an electron beam or a X ray, etc.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to photosensitive compositions.

(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 light using a mask that forms a desired pattern, and then developing, rinsing, etc. In this method, a resist pattern is formed by performing the above processing, and further, the exposed wafer is etched using the resist pattern as an etching mask, thereby forming lines or windows of minute width. In such microfabrication technology, the accuracy of semiconductor devices depends on the performance of the photoresist used, such as the resolution on the substrate,
It depends on the accuracy of photosensitivity, adhesion to the substrate, resistance to etchant, etc.

By the way, as a photoresist used for the above-mentioned resist pattern, for example, a polysilane polymer is attracting attention. Such photoresists include JP-A-Sho Go
There is one described in JP-228542. The polysilane of the present invention photodepolymerizes when irradiated with actinic radiation to produce a volatile product, so this property can be used as a photoresist for positive pattern formation. However, such dry development has a problem in that fine patterns cannot be formed with high accuracy.

One possible method for solving these problems is to perform alkaline development. However, since polysilane and polysiloxane are insoluble in alkaline solutions, there is a problem in that they cannot be developed in alkaline form.

(Problems to be Solved by the Invention) The present invention has been made to solve the above-mentioned problems of the conventional art. The present invention aims to provide a photosensitive composition comprising a polysilane-based or polysiloxane-based polymer that can be formed.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a photosensitive composition comprising a polymer represented by the following general formula (1) or (II).

R1 Strike 2 ■ However, R1-R4 and R14 to R1□ in the formula may be the same or different, and each has a hydrogen atom and a carbon number of 1 to 1.
0 aliphatic group, unsubstituted or substituted aromatic group having 6 to 14 carbon atoms, R5-R8 may be the same or different, hydrogen atom, hydroxyl group, alkoxy group, aliphatic group having 1 to 10 carbon atoms, A group group, an unsubstituted or substituted aromatic group having 6 to 14 carbon atoms, R9 to RI3i'j'-, which may be different or different, each containing a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a carbon Number 1 to 12 alkoxy groups, cyano groups, nitro groups, hydroxy groups, m is a positive integer, and n is a positive integer including zero.

Specific examples of the benzyl ether introduced into the above general formula (1) or (II) are shown below.

Specific examples of the structural unit represented by the above general formula (1) or (II) are shown below.

→S1← →S I +-+S I→-C
H2CH2Cll3 CH21(CC)13 CH3 +S 1÷--(-3i÷ →S i +-+S
1→-CH2C6H11C)+2 CH2CH2 CH2C3H7CH2 →S1-0÷-÷Si -0← -+Si -
0÷-÷S1-0←CH-CH3CH-CH3 CII3 C113-
(-Si-0→-→S1-0← The photosensitive composition of the present invention has the above general formula (I) or (
In addition to the polymer having the structural unit represented by If),
A sensitizer such as a benzophenone derivative, an acetophenone derivative, an anthracene derivative, etc. may be incorporated.

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

First, a base resin liquid dissolved in a nail machine solvent is applied onto a substrate by a spin coating method or a dipping method, and then dried to form a base resin film. Examples of the substrate used here include a single silicon single crystal wafer, the same wafer with various coatings such as an insulating film and a conductive film deposited on its surface, or a mask blank. As the base resin, a resin that can be removed by oxygen gas plasma is suitable, and examples thereof include novolac resin, polyimide resin, rubber-based negative resist, novolac-based positive resist, polystyrene, polymethyl methacrylate, etc. can. The six solvents for the base resin are not particularly limited, and include, for example, toluene, xylene, 0-dichlorobenzene,
Chloroform, j-tanol, isopropyl alcohol,
Cyclobe.

Examples include tanone, cyclohexanone, cellosolve acetate, and methyl ethyl ketone. The drying conditions for the base resin film are usually 50 to 250°C for 0.5 to 120 minutes, preferably 80 to 220°C for 1 to 90 minutes.

Subsequently, a resist solution consisting of the photosensitive composition of the present invention dissolved in an organic solvent is applied onto the base resin film by a spin coating method or a dipping method, and then dried to form a photoresist film. The organic solvent used here may be the same as the base resin described above. The drying conditions for such a photosensitive film are usually 50 to 20 DEG C. for 0.5 to 120 minutes, preferably 80 to 220 DEG C. for 1 to BO minutes.

Next, the photoresist film is exposed to ultraviolet rays, visible light,
Exposure is performed by selectively irradiating energy beams such as electron beams and X-rays. Subsequently, a development process is performed using an appropriate alkaline solution. As a result, the exposed portion of the photoresist film is dissolved and removed. The alkaline aqueous solution used here may be any one that quickly dissolves the exposed areas of the photosensitive film and has an extremely low dissolution rate for other non-exposed areas.
Examples include ammonia-based aqueous solutions such as tetramethylammonium aqueous solutions, and inorganic alkali aqueous solutions such as potassium hydroxide and sodium hydroxide. Subsequently, after drying at 100 to 200°C for 30 seconds to 120 minutes, preferably at 120 to 180°C for 1 to 90 minutes, the underlying resin film exposed from the photoresist film that has been selectively dissolved and removed by the development. A predetermined resist pattern is formed by etching away the resist using an oxygen reactive etching method. Thereafter, using the resist pattern as a mask, a substrate consisting of a single silicon crystal wafer, the same wafer with various wave films such as an insulating film or a conductive film deposited on its surface, or a mask blank is selectively etched to form a predetermined pattern. form a pattern.

(Function) The photosensitive composition of the present invention has the general formula (1) or (II)
), it is composed of polymers represented by
Energy rays such as electron beams and X-rays decompose the irradiated part and produce components that are soluble in alkaline aqueous solution, so a fine pattern can be formed with high precision by exposure to the energy rays and development with an alkaline aqueous solution. can.

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

Example 1 Polymer (2) in which 75% of the phenol units were converted to orthonitrobenzyl ether was synthesized from polymer (1) of the following structural formula (A) and orthonitrobenzyl chloride. Subsequently, this polymer (1) was dissolved in cyclohexanone to form a photosensitive liquid, and this photosensitive liquid was applied onto a silicon single crystal wafer using a spinner and dried to form a photosensitive film with a thickness of 0.7 μm. Subsequently, a mask having a pattern with an interval of 0.5 μm was brought into contact with this photoresist film, and a high-pressure mercury lamp (CA800) was used.
Contact exposure was performed using the following method. Next, the exposed photoresist film was developed with a 4% aqueous solution of tetramethylammonium hydroxide, resulting in a 0.5% film faithful to the mask pattern.
A pattern with a width of 5 μm could be formed with high precision.

+5t-O→-H [Al Example 2 First, a phenol novolac type resist (product name: 0PPR800 manufactured by Tokyo Ohka Co., Ltd.) was applied on a silicon wafer using a spinner, and dried to form a resist film with a thickness of 1.5 μm. Thereafter, a photosensitive solution consisting of polymer 1 dissolved in cyclohexanone as in Example 1 was applied onto the resist film using a spinner and dried to form a photosensitive film with a thickness of 0.6 μm. Subsequently, as in Example 1, contact exposure,
A 0.5 μm pattern was formed by developing with a 4% aqueous solution of tetramethylammonium hydroxide. Next, the silicon wafer was heated to 0.05 torrs O
When treated with oxygen plasma for 30 minutes under conditions of , OC/i, a 0.5 μm pattern could be formed with high precision.

Examples 3 to 5 Three kinds of photosensitive solutions in which polymers of the following structural formulas [B], [C), and (D] were dissolved in cyclohexanone were applied to phenol novolac type resists ( A 1.5 μm thick resist film made of Tokyo Ohka Co., Ltd. product 220FPR800) was coated with a spinner and dried to form a 0.6 μm thick photoresist film, followed by contact exposure.
When development was performed with a 4% aqueous solution of tetramethylammonium hydroxide and further oxygen plasma treatment was performed, patterns of 0.5 μm could be formed with high precision.

→S1-〇÷-431-0÷-DC113 (30%) (
70%) [B] CH3CH3 →81÷---÷81→- CII02)15C1lc2115 (20%) (80%) [C3 [D] [Effects of the Invention] As detailed above, the photosensitive composition of the present invention According to the material, the irradiated part can be decomposed by energy rays such as ultraviolet rays, visible rays, electron beams, and X-rays to produce components that are soluble in alkaline aqueous solution. It has remarkable effects such as being able to form fine patterns with high precision and being effectively usable in photoetching processes for semiconductor devices and the like.

Claims (1)

[Scope of Claims] A photosensitive composition comprising a polymer having a structural unit represented by the following general formula (I) or (II). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) However, R_1 to R_4 and R_1_4 to R_1_ in the formula
7 may be the same or different, and each represents a hydrogen atom,
An aliphatic group having 1 to 10 carbon atoms, an unsubstituted or substituted aromatic group having 6 to 14 carbon atoms, R_5 to R_8 may be the same or different, and a hydrogen atom, a hydroxyl group, an alkoxy group,
The aliphatic group having 1 to 10 carbon atoms, the unsubstituted or substituted aromatic group having 6 to 14 carbon atoms, and R_9 to R_1_3 may be the same or different, and each may be a hydrogen atom, a halogen atom,
An alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a cyano group, a nitro group, a hydroxy group, m is a positive integer, and n is a positive integer including zero.