EXTREME ULTRAVIOLET PHOTOLITHOGRAPHY MASK, WITH RESONANT BARRIER LAYER

摘要

The invention relates to extreme ultraviolet photolithography masks that operate in reflection. These masks comprise a lower mirror covering a substrate, and two types of reflecting zones Z1 and Z2 in order to form a phase shift mask. An etch stop layer is interposed between the lower mirror and an upper reflective structure. This layer has a thickness such that it behaves like a reflective resonant cavity surrounded by the upper and lower reflective structures.