PROJECTION EXPOSURE APPARATUS USING ASSISTANT MASK

摘要

A photolithographic projection system for transferring a predetermined pattern from a photomask to a wafer includes a radiation source and a grating mask. The radiation source projects radiation along a path through the photomask toward the wafer. The grating mask is positioned along the radiation path and is separate from the photomask. In a method for transferring a predetermined pattern from a photomask to a wafer, radiation is projected along a path through a grating mask and a photomask toward the wafer, and the grating mask is separate from the photomask.