Patent ID: 7462426
Filing Date: 2008-12-09
Classification: G02B,G03C,G03F

Abstract:
1. A method for producing a phase mask for the projection or reflection of a structure into an image plane, comprising: providing a substrate; forming a first semitransparent layer on the substrate, wherein the first semitransparent layer is configured to add a first phase rotation to a light beam passing through the first semitransparent layer; forming a second semitransparent layer on the first semitransparent layer, wherein the second semitransparent layer is configured to add a second phase rotation to a light beam passing through the second semitransparent layer; removing selected portions of the first and the second semitransparent layers in the vicinity of at least two partial regions on the substrate so as to form at least two first structure elements at the at least two partial regions of the substrate, wherein each of the first structure elements comprises the first and second semitransparent layers and has a first degree of transmission; and removing the second semitransparent layer at one of the at least two partial regions so as to form a second structure element with a second degree of transmission, wherein the second degree of transmission differs from the first degree of transmission.