Translator Disclaimer
8 August 1993 Phase-contrast lithography
Author Affiliations +
Phase contrast lithography using an annular-shaped phase only filter on the pupil plane of the projection optics was found to enlarge depth of focus for lines and spaces, isolated lines, spaces and hole patterns. The lines and spaces and isolated lines prefer an annular illumination. On the contrary, higher coherent illumination was effective for isolated spaces and hole patterns using the same phase modulation. It is not necessary to change the phase filter for each lithographic level. Phase contrast lithography gives us larger depth of focus in combination with halftone phase shifting mask. The phase filter does not have the problem of heating, and has high efficiency of exposure light. Several simulation results are presented, and the possibility of the phase contrast technology becoming a candidate for quarter micron lithography is discussed.
© (1993) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Soichi Inoue, Tadahito Fujisawa, Satoshi Tanaka, Shuichi Tamamushi, Yoji Ogawa, and Makoto Nakase "Phase-contrast lithography", Proc. SPIE 1927, Optical/Laser Microlithography, (8 August 1993);


Back to Top