Patent ID: 6767672
Filing Date: 2004-07-27
Classification: G03F

Abstract:
A method for forming a multi-transmittance photomask on a transparent substrate comprising the steps of:forming a first light blocking layer on the substrate; forming a phase-shifting layer on the first light blocking layer; forming a second light blocking layer on the phase-shifting layer; forming a third light blocking layer on the second light blocking layer; removing a portion of the third light blocking layer to define a first pattern area and expose a portion of the second light blocking layer; removing a portion of the exposed portion of the second light blocking layer to define a second pattern area, the remaining portion of the third light blocking layer defining a third pattern area; wherein the first pattern area has a first transmittance P1 of an exposing light, the second pattern area has a second transmittance of P2 of the exposing light, and the third pattern area has a third transmittance P3 of the exposing light, having a relationship wherein P2>P1>P3.