Patent ID: 7483804

Claim:
A method of patterning resist coated wafers, the method comprising: lithographically patterning resist coated wafers using predetermined exposure dose and focus settings; obtaining CD metrology data from test areas on the patterned wafers, wherein different groups of test areas are selected for two or more of the patterned wafers, and wherein the obtaining CD metrology data further comprises selecting a number of test areas on each processed wafer using the equation m map =mN−y, wherein m map is the number of different test areas on the patterned wafers, m is the total number of test areas on each patterned wafer, N is the number of patterned wafers, and y is the total number of repeated test areas having the same position on the patterned wafers; constructing a CD metrology data map from the CD metrology data; and establishing adjusted exposure and/or focus settings using the CD metrology data map.