Phase mask for photolithographic projection and process for its preparation

Abstract

Abstract A substrate (11) of light-transparent material with a mask pattern (12) of light-absorbing material on it is provided. The substrate (11) has first regions (13) and second regions (14) which are not covered by the absorbing material. The optical thickness of the substrate (11) in the first regions (13) differs from that in the second regions (14) in such a way that there is a phase difference of 180 DEG + 60 DEG between light which has passed through the first regions (13) and light which has passed through the second regions (14). To produce the phase mask, the first regions (13) are produced by isotropically etching the light-absorbing material and the second regions (14) by anisotropically etching the substrate (11).

Inventors

• 👤 Christoph Dr. rer. nat. Dipl.-Phys. Nölscher
• 👤 Leonhard Dr. Rer. Nat. Dipl.-Phys. Mader

Bibliographic Details