Patent ID: 6969571

Claim:
An exposure method using a complementary divided mask comprising: a first step for detecting positions of alignment marks provided at the respective exposure objective unit regions, aligning the complementary divided mask based on said detected positions of alignment marks, and exposing the respective exposure objective unit regions in a first region including a plurality of exposure objective unit regions at the middle portion of a semiconductor wafer; and a second step for determining coordinates of exposure objective regions in a second region, outside of said first region, where alignment of said complementary divided mask by detection of alignment marks cannot be used, aligning said complementary divided mask based on said positions of alignment marks detected in said first step, and exposing the regions in said second region, said first step comprises the steps of: obtaining alignment coefficients based on detection result of positions of said alignment marks, and establishing a first function equation using said alignment coefficients as coefficients for obtaining alignment correction values of said complementary divided mask; obtaining said alignment correction values according to said first function equation; and aligning said complementary divided mask based on said alignment correction values and exposing regions, said second step comprises the step of: using said alignment coefficients of said function equation obtained at said first step to establish a second function equation for obtaining alignment correction values of said semiconductor wafer and alignment correction values of the respective exposure objective unit regions of said second region; using said second function equation to obtain reference coordinates of said semiconductor wafer and coordinates of the respective exposure objective unit regions of said second region; and aligning said complementary divided mask based on said reference coordinates of said semiconductor wafer and said coordinates of the respective exposure objective unit regions of said second region, and exposing regions.