A method for improving the performance of photolithographic equipment and for increasing the lifetime of the optics thereof

摘要

In a photolithographic process using a photolithographic mask having opaque mask areas and transparent mask areas, the opaque mask areas corresponding to a pattern to be transferred onto a semiconductor wafer to form on the wafer a pattern of active structures, a method for improving the performance of the photolithographic equipment and for increasing the lifetime of the optics thereof characterized by providing auxiliary opaque mask areas (2;3;4) in areas of the mask not covered by active opaque mask areas (1), so as to reduce a transmission factor of the mask.