Alcohol-assisted photocrosslinking of poly(vinyl alcohol) for water-soluble photoresists

Patterned negative-tone images on the polymer film have been prepared based on the photoinduced crosslinking of water soluble poly(vinyl alcohol) (PVA ) in the presence of various alcohols. Irradiation of a polymer film contai ning PVA, a photoacid generator and an alcohol as a crosslinker with 254-nm UV through a photomask followed post-exposure bake (PEB) allowed generatio n of negative-tone relief images at 5 mum resolution in the polymer film. A mong various alcohols tested, aromatic alcohols such as pyrogallol and reso rcinol were found to be superior to aliphatic alcohols such as sucrose and inositol in terms of resist sensitivity,