Patent ID: 7226725

Claim:
A method for forming patterns for a semiconductor device, comprising: forming a first resist layer on a target layer to be etched on a semiconductor substrate; forming a second resist layer by coating the first resist layer with a negative resist composition, wherein the negative resist composition comprises an alkali-soluble base polymer having an epoxy ring substituent, said alkali-soluble base polymer having an epoxy ring substituent comprising one of an epoxy novolac resin, an epoxy-substituted polyhydroxystyrene, a glycidyl (meth)acrylate repeating unit or a (meth)acrylate repeating unit with an alicyclic epoxy group, a silicon-containing crosslinker having multiple hydroxy groups, and a photoacid generator; pre-baking the second resist layer; exposing the second resist layer; performing post-exposure baking on the exposed second resist layer; developing the exposed second resist layer to form a second resist layer pattern; etching the first resist layer using the second resist layer pattern as an etching mask to form a first resist layer pattern; and etching the target layer using the first resist layer pattern as an etching mask.