Patent ID: 7803500

Claim:
A photomask comprising: a transparent substrate; a phase shift layer for shifting a phase of exposure light on the transparent substrate; a light shielding layer on the phase shift layer; a circuit pattern, formed in a chip region, including a first opening through the phase shift layer and exposing the transparent substrate; a first non-circuit pattern, formed outside of the chip region and in an area within fifteen millimeters distance from the chip region, including a second opening through the light shielding layer and exposing the phase shift layer; and a second non-circuit pattern for adjusting the relative positions of the photomask and an exposure system, formed outside of the chip region and in an area over fifteen millimeters distance from the chip region, including a third opening through the light shielding layer and the phase shift layer and exposing the transparent substrate, wherein: in the chip region, the light shielding layer is removed; and the transparent substrate under the second opening is wholly covered with the phase shift layer.