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 containing PVA, a photoacid generator and an alcohol as a crosslinker with 254-nm UV through a photomask followed post-exposure bake (PEB) allowed generation of negative-tone relief images at 5 µm resolution in the polymer film. Among various alcohols tested, aromatic alcohols such as pyrogallol and resorcinol were found to be superior to aliphatic alcohols such as sucrose and inositol in terms of resist sensitivity