JPH03103855A - Resist composition - Google Patents

Abstract

PURPOSE:To enhance oxygen plasma resistance sufficiently and also sensitivity and resolution by incorporating a specified ladder-type silicone resin for the upper layer resist of a 2-layer resist structure. CONSTITUTION:The silicone resin to be used is the ladder type silicone resin represented by formula I in which R1 is 2 - 4 alkenyl, and each of (l), (m), and (n) is a positive integer of 1 - 1000, thus permitting the phenolic hydroxyl groups and the alkenyl groups combined with the side chains to effectively act on each other and accordingly, oxygen plasma resistance and sensitivity to be enhanced and deterioration of resolution to be avoided by use of alkali development.

Description

[Detailed Description of the Invention] [Summary] Regarding the resist composition, when used as an upper layer resist in a two-layer resist process, it has sufficient oxygen plasma resistance, and
For the purpose of providing a resist composition with excellent sensitivity and resolution, a ladder-type silicone resin represented by the following formula: (In the above formula, R, may be the same or different from each other, and 2 ~
42, m and n each represent a positive integer from 1 to 1000).

(In the above formula, R1 may be the same or different from each other, and 2 to
represents an alkenyl group having 4 carbon atoms, and 42, m and n each represent a positive integer from 1 to 1000).

(1) (2) [Industrial Application Field] The present invention relates to a resist assembly. More specifically, the present invention relates to a negative resist &rl material useful in patterning semiconductor devices, and particularly useful as an upper layer resist in a two-layer resist process. The resist composition of the present invention can be advantageously used in manufacturing semiconductor devices such as LSI and VLSI. The present invention also relates to a resist 1 pattern and method using such a resist material.

[Conventional technology]

As semiconductor integrated circuits become more highly integrated, the pattern width of LSIs tends to become smaller and smaller. Current 256KDRA
The minimum line width of l'l is about 1.2 marks, and is carried out using a positive photoresist in the form of this pattern or by reduced projection exposure using a g-line. However, such reduced projection exposure reduces resolution due to problems such as standing waves generated in the resist 1 and film, side reflections from wiring, and shallow depth of focus. Therefore, there is a demand for the development of a process to solve this problem.

Currently, a two-layer resist process is being considered. 2
The upper layer resist material of the layered resist is a negative resist made of a mixture of a polymer containing silicon atoms and an azide or bisazide compound, and a mixture of an alkali-fusible resin containing silicon atoms and an O-naphthoquinonediazide derivative. There is a body type resist consisting of a body. However, negative resists generally use an organic solvent as a developer, so they swell during development and do not have sufficient resolution, and positive resists have low oxygen plasma resistance due to their low silicon content. There are problems such as a pattern width shift occurring during transfer of the upper layer pattern, and there is a need for the development of an upper layer resist material for a two-layer resist that solves these problems.

[Problem to be solved by the invention]

Therefore, the object of the present invention is to (3) (4) have sufficient oxygen plasma resistance when used as an upper layer resist in a two-layer resist process, and also have poor sensitivity and resolution. An object of the present invention is to provide a resist composition.

[Means to solve the problem]

In order to achieve the above object, the present inventors have conducted intensive research and found that a ladder-type silicone resin having a phenolic hydroxyl group and an alkenyl group in its structure is useful as an upper layer resist material of a two-layer resist. discovered that this resist material has excellent resolution because it can be developed with alkali.

According to the present invention, therefore, a ladder-type silicone resin represented by the following formula: (In the above formula, R, may be the same or different from each other, and 2 to
represents an alkenyl group having 4 carbon atoms, such as a vinyl group or an allyl group, and 1. m and n are each 1
1000) is provided.

According to the present invention, a resist solution is prepared by dissolving the ladder type silicone resin as described above in an organic solvent, this resist solution is applied as an upper layer resist of a two-layer structure resist, and the upper layer resist is exposed to an exposure light source. A method of forming a resist pattern is also provided, which comprises exposing the resist pattern to an image pattern of ultraviolet light, and further developing the exposed upper layer resist with an alkaline developer.

The ladder-type silicone resin used in the resist of the present invention can have various structures.

In addition, various organic solvents such as alcohols, ketones,
Can be dissolved (5) (6) in ether, etc. Using the obtained resist solution,
A two-layer resist process is carried out according to conventional techniques. However, in the method of the present invention, alkaline development of the upper resist layer is possible.

[Function] In the ladder-type silicone resin used in the resist composition of the present invention, the phenolic hydroxyl groups and alkenyl groups contained as side chains in its structure interact effectively with each other, resulting in excellent oxygen plasma resistance. It is possible to maintain excellent sensitivity and ensure excellent sensitivity, which has been difficult to achieve at the same time.Furthermore, since alkaline development is possible, deterioration in resolution can be avoided.

〔Example〕

Next, the present invention will be explained by way of examples thereof.

8 g of pyridine was added to 100 me of silicone resin methyl isobutyl ketone (MIBK) and cooled to -60'C. 4-
24.6 g of chlorophenyltrichlorosilane, 16.2 g of vinyltrichlorosilane and 15 g of ion-exchanged water
d was added dropwise in sequence. After dropping, gradually raise the temperature to 90°C.
The mixture was heated for 5 hours. After the reaction was completed, the organic layer was washed twice with ion-exchanged water, and then the organic layer was separated, 30 g of trimethylchlorosilane and 22 g of pyridine were added, and the mixture was heated at 60° C. for 3 hours. Thereafter, the organic layer was washed again with ion-exchanged water 10 times, and then the organic layer was separated, concentrated, and poured into acetonitrile to precipitate and collect the resin. The obtained resin was dissolved in 50 trdl of benzene, and dried by drying. The silicone resin obtained in this example has the following structure: rρ (7) (8) and f) MW = 3. 2 XIO', Mw
/M. -2.3.

Akiyoshi Silicone Resin Coordination The procedure of Example 1 above was repeated, but in this example 18.6 g of allyltrichlorosilane was used instead of 16.2 g of vinyltrichlorosilane. The silicone resin obtained in this example has the following structure: 1'V (in the formula, n is an integer necessary to obtain the following V),
And π. = 3. 5 XIO', 厠-W/U-A2
．． It was 2.

20g of the silicone resin obtained in Example 1 was dissolved in 100% dry ether, 3g of metallic magnesium and 21g of t-butyl perbenzoate were added thereto, and the mixture was reacted at reflux temperature for 1 hour. . After the reaction was completed, 20 g of concentrated hydrochloric acid was added and the reaction was continued for an additional hour at reflux temperature.

Thereafter, the reaction solution was washed twice with a 5% aqueous sodium hydrogen carbonate solution, and further washed with ion-exchanged water until the washing water became neutral. Next, the ether layer was separated, concentrated, and poured into acetonitrile to precipitate and recover the resin. The obtained resin was dissolved in 50% benzene and freeze-dried.

In this example, even when the silicone resin of Example 2 was used in place of the silicone resin of Example 1, the desired silicone-modified resin was obtained.

In the form of a clay resist pattern, 1 g of the silicone-modified resin obtained in Example 3 above was mixed with MIBK.
9 g to prepare a resist solution. Separately, eight Z-
1350 resist (manufactured by Hoechst) was spin-coated onto a silicon substrate to a film thickness of 2cm, and then heated at 200''C for 1 hour to harden it.

(9) (10) After spin-coating the previously prepared resist solution onto the obtained lower resist film to a film thickness of 0.2-, the temperature was heated to 80°C.
A 20 minute preview was conducted. Eximer laser (KrF) light was patterned onto the obtained upper resist film through a mask, and then developed using an alkaline aqueous solution, followed by rinsing with ion-exchanged water. Next, the substrate to be processed is placed in a parallel plate type dry etching equipment.
The upper layer pattern was transferred to the lower layer using oxygen plasma. As a result, this two-layer structure resist has a power of 5 mJ/c+fl.
0. 4. We were able to resolve the line and space pattern of tnh1.

〔Effect of the invention〕

According to the present invention, it has sufficient oxygen plasma resistance to be used as an upper layer resist of a two-layer structure resist,
In addition, a negative resist material with excellent sensitivity and resolution can be obtained, and pattern formation can therefore be advantageously performed.

(11)

Claims (1)

[Claims] 1. Ladder type silicone resin represented by the following formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the above formula, R_1 may be the same or different from each other, and 2
(1, m, and n each represent a positive integer of 1 to 1000).