Method for forming an opening on an alternating phase shift mask

摘要

In a method of manufacturing a phase shift mask, an opening is produced by lithography in a second layer (32) arranged on an opaque layer (10). An etching step in which a first subregion (12) on a deep-etched surface of the transparent substrate (18) is uncovered is carried out in order for the opening to be transferred into the opaque layer (10) and into the substrate (18) below. Widening of the opening in the second layer (32) and etching so as to transfer the opening into the opaque layer (10) lead to the formation of a second subregion (14), which adjoins the recessed first subregion (12) and surrounds it in rim form, on the surface of the transparent substrate (18).