Radiation imagery chemistry: process – composition – or product th – Diazo reproduction – process – composition – or product – Composition or product which contains radiation sensitive...
Reexamination Certificate
1999-06-01
2004-11-09
Chu, John S. (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Diazo reproduction, process, composition, or product
Composition or product which contains radiation sensitive...
C430S191000, C430S192000, C430S193000
Reexamination Certificate
active
06815140
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a positive resist composition which comprises an alkali-soluble novolac resin and a radiation-sensitive quinonediazide compound and which is suitably used in processing of fine semiconductors integrated circuits.
DESCRIPTION OF RELATED ART
The fine processing of semiconductor integrated circuits has usually been performed by adopting a lithography process using a resist composition. Among the resist compositions positive working types are used in many cases because of their generally superior resolution. The positive resist compositions comprise generally an alkali-soluble ingredient and a radiation-sensitive ingredient. Specifically, they comprise a novolac resin as an alkali-soluble ingredient and a quinonediazide compound as a radiation-sensitive ingredient. Such a novolac-quinonediazide type positive resist utilizes the fact that the quinonediazide compound, which is alkali-insoluble, is decomposed by the action of radiation to generate a carboxylic group, which makes the compound alkali-soluble.
In recent years, the integrated circuit has become finer and finer with higher integration, and a pattern formation at a sub-micron level has become required. As the result, a positive resist composition having a higher resolution has become desired. For obtaining a finer pattern, so-called chemical amplification resists, which utilize the chemical amplifying effect attained by an acid-generating agent, have also been used in some field. There is still, however, a persistent need for the novolac-quinonediazide type resists.
The resolution of the novolac-quinonediazide type positive resists can be improved by increasing the amount of quinonediazide compound to some extent. However, when the amount of quinonediazide compound is increased too much, the light absorption of the resist becomes very great so that the profile is deteriorated and a rectangular pattern can not be obtained.
The purpose of the present invention is to improve the resolution in the novolac-quinonediazide type positive resists without lowering other resist performances excessively.
As the result of researches, the present inventors have found that the resolution of a novolac-quinonediazide type positive resist composition, which comprises an alkali-soluble novolac resin and a radiation-sensitive quinonediazide compound, can be improved by adding a certain compound. Thus, the present invention was completed.
SUMMARY OF THE INVENTION
The present invention provides a positive resist composition which comprises a novolac resin, a radiation-sensitive quinonediazide compound and a thioxanthone compound represented by the following formula (I):
wherein R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, R
7
and R
8
independently represent hydrogen, halogen, alkyl, alkoxy, aryl, carboxyl or alkoxycarbonyl.
REFERENCES:
patent: 4356255 (1982-10-01), Tachikawa et al.
patent: 4701399 (1987-10-01), Nagano et al.
patent: 4803145 (1989-02-01), Suzuki et al.
patent: 5221592 (1993-06-01), Khanna et al.
patent: 5252686 (1993-10-01), Aoai et al.
patent: 5380620 (1995-01-01), Namiki et al.
patent: 5547808 (1996-08-01), Watanabe
patent: 5576143 (1996-11-01), Aoai et al.
patent: 5612164 (1997-03-01), Canize et al.
patent: 5650261 (1997-07-01), Winkle
patent: 5837417 (1998-11-01), Rahman et al.
patent: 0662636 (1995-07-01), None
patent: 0831371 (1998-03-01), None
Moriuma Hiroshi
Takata Yoshiyuki
Uetani Yasunori
Birch & Stewart Kolasch & Birch, LLP
Chu John S.
Sumitomo Chemical Company Limited
LandOfFree
Positive resist composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Positive resist composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Positive resist composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3300427