Patent ID: 6841316

Claim:
A method for producing a phase shift mask having structures, which comprises the steps of: providing a substrate having a transparent substrate material layer, a chromium layer with a given thickness coating the transparent substrate material layer, and a further layer disposed on the chromium layer, the further layer selected from the group consisting of a photosensitive layer and a charge-sensitive layer forming a resist mask after treatment or application with charged particles; structuring the further layer using a beam of one of laser light and charged particles resulting in a first structure; transferring the first structure to the chromium layer by performing a first etching step resulting in etched-in structures each having a first depth and a remainder of the chromium layer disposed below each of the etched-in structures having a reduced thickness; applying a further charge-sensitive layer on the chromium layer; structuring the further charge-sensitive layer using a further beam of charged particles resulting in a second structure; and transferring the second structure down into the transparent substrate material layer by performing a second etching step.