FOCUS MONITORING METHOD USING MULTI-PHASE FOR CHECKING EASILY VARIATION OF FOCUS

摘要

PURPOSE: A focus monitoring method is provided to check easily the variation of focus by using a predetermined phase shift mask. CONSTITUTION: A phase shift focus monitoring mask(100) with a plurality of phases is provided. When focus is consistent, a chrome pattern(114) becomes a rectangle type structure. When focus is inconsistent, the chrome pattern deforms. Whether defocus is generated or not is checked by inspecting the shape of the chrome pattern using a microscope.