Patent ID: 8158305

Claim:
A photomask for extreme ultraviolet lithography, comprising: a reflection layer disposed over a transparent substrate, the substrate having a main chip region and a frame region, the reflecting layer being capable of reflecting extreme ultraviolet light incident thereon; a phase shifter pattern disposed over the reflection layer and selectively exposing the reflection layer; an absorber pattern disposed over the phase shifter pattern of the frame region; and a reflectivity reduction region disposed in the absorber pattern, the reflectivity reduction region being capable of shielding the extreme ultraviolet light, wherein the reflectivity reduction region is formed by doping with at least one doping material selected from the group consisting of carbon-containing materials, nitrogen-containing materials, and oxygen gas onto the absorber pattern, the reflectivity reduction region has a height not more than a depth of the absorber pattern, and at least one surface of the reflectivity reduction region is exposed.