Feasibility of stereophonic projection lithography applying a parabolic magic mirror system

A new stereophonic projection lithography applying a parabolic magic mirror system was proposed. An aperture was also opened at the bottom of lower mirror, and a transparent reticle was placed in place of a reflective object article used in the conventional magic mirror system. Toward the transparent reticle, illumination light was irradiated obliquely upward from the bottom. Thus, images of curved reticle patterns were projected at the aperture center of the upper mirror, and 200 μ m line-and-space resist patterns were actually printed on a silicon wafer when a flat reticle was used. On the other hand, it was clarified by tracing light rays in the meridional plane that the resolution depended on the field size, the extent of used mirror parts, and the defocus. It is considered that aimed 50 μ m patterns will be printable if the illumination system is improved. The new method is feasible and hopeful.