EXTREME ULTRAVIOLET LITHOGRAPHY PROCESS AND MASK WITH REDUCED SHADOW EFFECT AND ENHANCED INTENSITY

摘要

An extreme ultraviolet (EUV) mask comprises a substrate, a first reflective layer above a surface of the substrate, and a second reflective layer over the first reflective layer. The second reflective layer has various openings that define a first state and a second state. The first state includes the first reflective layer and is free of the second reflective layer. The second state includes both the first and second reflective layers. The first state has a first reflection coefficient and a first reflectivity. The second state has a second reflection coefficient and a second reflectivity. A phase difference between the first and second reflection coefficients is about 180 degrees.

主权项

1. An extreme ultraviolet (EUV) mask, comprising:
a substrate; a first reflective layer above a surface of the substrate; and a second reflective layer over the first reflective layer, wherein the second reflective layer has various openings that define a first state and a second state, wherein the first state includes the first reflective layer and is free of the second reflective layer, and the second state includes both the first and second reflective layers, wherein the first state has a first reflection coefficient and a first reflectivity, the second state has a second reflection coefficient and a second reflectivity, and a phase difference between the first and second reflection coefficients is about 180 degrees.