Patent ID: 6841801

Claim:
A mask for use in forming a pattern on a substrate, comprising: a mask substrate having a transparency to an exposure light; a layer of material having an optical transmissivity that is less than that of said mask substrate with respect to the exposure light, said layer of material only existing on the mask substrate at a central region of the mask substrate to thereby form a main pattern, wherein no other material having said optical transmissivity is present on said mask substrate; and a plurality of phase shifters disposed on each side of the main pattern at first transmitting regions of the mask, respectively, said phase shifters being transparent to said exposure light, and the mask having a plurality of second transmitting regions at each side of the main pattern, the mask being transparent to said exposure light at said second transmitting regions, respective ones of said phase shifters being alternately disposed, in at least one of two orthogonal directions, with respective ones of said second transmitting regions on each side of the main pattern, the thickness of the mask at said phase shifters being different from the thickness of the mask substrate at said second transmitting regions, whereby when the exposure light is transmitted through the mask, light is blocked by said main pattern for use in forming an isolated pattern on a substrate and the light transmitted through said first and second transmitting regions will have a phase difference such that a diffraction pattern is produced.