A history of resolution enhancement technology

Resolution enhancement techniques (RETs) have enabled the adoption of optical lithography well below the wavelength of the exposing light. Examination of the history of RET and recent developments shows that only 3 of the 4 independent variables available for wavefront engineering have been utilized. This suggests that, with full utilization of polarization and other electromagnetic effects, optical lithography will be the manufacturing technology for ICs for the foreseeable future. (c) 2005 The Optical Society of Japan.