Reverse process for making chromium masks using silicon dioxide dry etch mask

摘要

On a substrate (1) covered with a chromium layer (2), a positive resist layer (3) is applied, exposed through an exposure mask with the mask pattern corresponding to the negative of the respective chromium pattern, developed, and blanket-coated with a less than or equal to 10 nm thick layer (4) of silicon dioxide. Then photoresist layer (3) and the silicon layer (4) thereon are lifted off, and finally the chromium layer (2) is dry-etched, the remaining silicon dioxide layer (4) being used as an etch mask. Chromium masks are used e.g. in the production of semiconductor circuits. By means of the reverse process, structures whose smallest dimensions are in the micrometer and the submicrometer range can be transferred into chromium layers with sharp edges.