Patent ID: 7595136

Claim:
A method of fabricating a chrome-less phase shift mask, the method comprising: forming a hard mask film on a surface of a mask body having a trench circuit area and a mesa circuit area; patterning the hard mask film to form a trench hard mask pattern on the trench circuit area; forming pre-pitting patterns in the trench circuit area by anisotropically etching the mask body using the trench hard mask pattern as an etching mask; patterning the hard mask film having the trench hard mask pattern to form a mesa hard mask pattern on the mesa circuit area and exposing a top surface of the trench circuit area; and forming phase shift hillock patterns in the mesa circuit area and phase shift pitting patterns in the trench circuit area by anisotropically etching the mask body using the mesa hard mask pattern as an etching mask, wherein hillock portions between the phase shift pitting patterns are formed lower than the top surfaces of the phase shift hillock patterns.