A new negative resist consisting of an anhydride, an acrylic acid, an epoxy crosslinker and a photoacid generator is introduced. In the exposed area, the epoxy groups of the crosslinker react with anhydride groups and/or carboxylic acids in the polymer under existence of photogenerated acid as a catalyst during post exposure baking (PEB). A 0.20 mu m pattern was resolved by an ArF exposure at a dose of 28 mJ/cm(2).