Polymers, resist compositions and patterning process

An acrylic resin containing hexafluoroisopropanol units has high transmittance to VUV radiation. A resist composition using the resin as a base polymer has high transparency, substrate adhesion, alkali developability and acid-elimination capability and is suited for lithographic microprocessing.

If you were to search for Polymers, resist compositions and patterning process using relaxed search criteria, these patents would come up:

What is claimed is:

1. A polymer comprising recurring units of at least one of the following general formulae (1a), (1b) and (1c): ##STR27##

wherein R is selected from the group consisting of hydrogen, an acid labile group, straight, branched or cyclic alkyl or fluorinated alkyl group of 1 to 20 carbon atoms, acyl group, and acyl group having a fluorinated alkyl moiety, R.sup.1 andR.sup.2 each are a hydrogen or fluorine atom, R.sup.3 is an acid labile group, R.sup.4 is an adhesive group, and R.sup.5 is a straight, branched or cyclic alkyl or fluorinated alkyl group of 1 to 20 carbon atoms.

2. A resist composition comprising the polymer of claim 1.

3. A chemically amplified, positive resist composition comprising (A) the polymer of claim 1, (B) an organic solvent, and (C) a photoacid generator.

4. The resist composition of claim 3 further comprising (D) a basic compound.

5. The resist composition of claim 3 further comprising (E) a dissolution inhibitor.

6. A process for forming a resist pattern comprising the steps of: applying the resist composition of claim 2 onto a substrate to form a coating, heat treating the coating and then exposing it to high-energy radiation in a wavelength band of 110to 180 nm or 1 to 30 nm through a photo mask, and optionally heat treating the exposed coating and developing it with a developer.

7. The pattern forming process of claim 6 wherein the high-energy radiation is an F.sub.2 excimer laser beam, Ar.sub.2 excimer laser beam or soft x-ray.