Photoresist monomers polymers thereof and photoresist...

Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Radiation sensitive composition or product or process of making

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C430S910000

Reexamination Certificate

active

06492088

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to photoresist monomers, polymers derived therefrom and photoresist compositions comprising the polymers. In particular, the present invention relates to polycarbonyl-derivative photoresist monomers, polymers thereof and photoresist compositions comprising the same that are suitable for photolithography processes employing KrF, ArF, VUV, EUV and similar light sources.
2. Description of the Background Art
Recently, chemical amplification-type DUV photoresists have been investigated in order to increase sensitivity in minute image formation processes for preparing semiconductor devices. Such photoresists are prepared by blending a photoacid generator and matrix resin polymer having an acid labile group.
In a photolithography process, an exposure of photoresist to light of a particular wavelength generates an acid from the photoacid generator that is present in the photoresist. The photo generated acid causes the main chain or the branched chain of the resin to decompose or become cross-linked. In addition, the acid removes the acid labile group and changes the polarity of the photoresist in the exposed region. This polarity change creates a solubility difference between the exposed portion and the unexposed portion in a developing solution, thereby allowing a pattern formation. The resolution of the pattern that is formed depends on the wavelength of the light source, i.e., in general, a shorter wavelength allows formation of more minute patterns.
In general, a useful photoresist (hereinafter, abbreviated as “PR”) has a variety of desired characteristics, such as excellent etching resistance, heat resistance and adhesiveness. In addition, a photoresist should be easily developable in a commercially readily available developing solution, such as 2.38 wt % aqueous tetramethylammonium hydroxide (TMAH) solution. However, it is very difficult to synthesize a photoresist polymer that satisfies all of these requisites.
To solve some of the problems described above, there has been developed a three-component PR composition comprising a polymer of Chemical Formula 1, prepared by cyclopolymerization of 2-(tert-butoxycarbonyl)bicyclo-2,5-diene, as a matrix resin; and a lithocholic ester compound as a dissolution inhibitor:
Although the polymer has excellent dry etching resistance, it requires an excess amount of the dissolution inhibitor which is transparent in the wavelength of 193 nm. Unfortunately, the excess amount of the dissolution inhibitor may result in precipitation or lowering of the glass transition temperature (T
g
). Thus, the above described three component mixture does not provide a satisfactory solution to the problems. Also, in order to improve the adhesiveness of the PR polymer to the wafer, the ratio of ‘y’ must be increased. However, if the amount of ‘y’ is increased, the developing solution (2.38 wt % TMAH) cannot be employed.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide photoresist monomers having excellent etching resistance, adhesiveness and photosensitivity.
Another object of the present invention is to provide PR polymers derived from such photoresist monomers and methods for preparing the same.
Yet another object of the present invention is to provide photoresist compositions comprising such PR polymers.
Still another object of the present invention is to provide a semiconductor device produced by using the above described PR composition.


REFERENCES:
patent: 6303266 (2001-10-01), Okino et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Photoresist monomers polymers thereof and photoresist... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Photoresist monomers polymers thereof and photoresist..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photoresist monomers polymers thereof and photoresist... will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2956316

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.