Projection optic system especially for photolithography for semiconductor processing has a filter with opaque and transmitting regions to provide an optimum intensity distribution for the projection

摘要

A projection optic system for producing fine detail images, e.g. for photolithography for the production of semiconductors, integrated circuits etc., has the beam modulated by a filter (1) with a pattern of opaque and transmitting areas. The invention describes additional areas which are partially transmitting. The filter has a quartz substrate (40) which a has thick coating (42) as non transmitting areas as well as a thinner (48) layer for partial transmission and cleared areas (46) for non restricted.