US Patent 8383316 Resists for lithography

New routes involving multi-step reversible photo-chemical reactions using two-step techniques to provide non-linear resist for lithography are described in this disclosure. They may provide exposure quadratically dependant on the intensity of the light. Several specific examples, including but not limited to using nanocrystals, are also described. Combined with double patterning, these approaches may create sub-diffraction limit feature density.