METHOD FOR CORRECTING PHASE SHIFT MASK AND PHASE SHIFT MASK SYSTEM

摘要

PROBLEM TO BE SOLVED: To correct the defect in a phase shift mask by forming a phase shift restoration mask by making the defect region of the first phase shift mask opaque and using the mask for exposure of the region covered by the opaque region. SOLUTION: The position of the defect in the position shift mask is determined (40) and the region having a need for restoration is delineated (40). Next, the region required to be restored on the first phase shift mask is made opaque (46). The pattern of the shape complementary with the restoration part is then delineated on the phase shift restoration mask and the design on the first mask is subtracted from the shape delineating the restoration region (47). In succession, adjustment is so executed that the restoration may be made without the third trimming mask (48). Exposure 51 of the first mask onto a wafer is executed and in succession second exposure 52 is executed by using the phase shift restoration mask. The restoration method acts successfully, insofar as the restoration region is not as large as to include the feature to prohibit the phase shift without the trimming mask in the patterns.