Patent ID: 8859168
Filing Date: 2014-10-14
Classification: G03F

Abstract:
1. A microlithography mask for illuminating a photoimageable material on a semiconductor wafer, comprising: a radiation transmissive substrate having a front side and a back side, the substrate having a plurality of recesses extending from the front side to a corresponding depth into the substrate along walls of the recesses, wherein the recesses are arranged in an array; and a mask material at the front side of the substrate, the mask material having openings arranged in rows/columns of the array, the openings corresponding to features to be formed on a wafer, the openings being at least partially aligned with the recesses and non-recessed portions on the substrate, wherein the openings are arranged at a constant pitch in the rows or in the columns, wherein a distance from one opening to another and the depth of the recesses are selected at least in part based on determining an interference of radiation at a focal distance from the openings, and wherein shortest distance between the walls of adjacent recesses varies for the recesses in the array, and wherein at least two non-recessed portions in a row or in a column are adjacent.