Inorganic resist phenomena and their applications to projection lithography

The mechanisms responsible for latent image formation in GexSe1-xresist are studied using computer simulation and laboratory experiments. The conditions for the occurrence of contrast enhancement, edge sharpening, feature-dependent amplification, and feature-dependent photodoping suppression are identified. Their role in optical projection lithography is characterized in terms of the Ag diffusion length, exposure time, and Ag2Se layer thickness. By appropriate selection of exposure and film thickness to control the lateral diffusion and photobleaching process, proximity effects caused by light diffraction can be compensated, small conventionally unresolved features can be printed, and the printability of open defects can be reduced. In the high-throughput regime, however, compensation cannot be obtained and the resolution is limited by the aerial image quality of the projection printer.