Twin-mask, and method and system for using same to pattern microelectronic substrates

摘要

A microelectronic substrate patterning system and method uses two or more copies of a mask pattern in the radiation path between the radiation source and the microelectronic substrate. The two or more copies are axially displaced from one another along the radiation path and are in axial alignment with each other along the radiation path. Thus, the mask pattern is imaged onto the microelectronic substrate as a result of interaction of the radiation with the multiple copies of the mask pattern in the radiation path. The mask pattern thereby images at an increased depth to focus compared to a single copy of the mask pattern. The two or more copies of the mask pattern may be used to increase the depth of focus of transmissive and reflective microelectronic substrate imaging systems. The mask copies may be identical or may be biased relative to the desired feature dimensions. Conventional microelectronic techniques may be used to fabricate the mask and to ensure alignment between the first and second copies of the microelectronic substrate mask pattern.