STRUCTURE FOR FORMING OVERLAY KEY OF MASK FOR EXPOSING SEMICONDUCTOR

摘要

PURPOSE: A structure for forming an overlay key for exposing a semiconductor is provided to conform a pattern of main cell area with a spatial frequency of the overlay key. CONSTITUTION: A chrome layer pattern(12) is formed on the substrate(11) so that a main cell area(13) is formed. Overlay keys(14) are formed at outsides of the main cell area(13). Here, a pitch(P) of chrome layer pattern(12) is accorded with a pitch(P') of the overlay keys(14). An aberration at a lens in an exposing equipment is due to the spatial frequency. Thereby, the misalignment due to the aberration can be prevented.