Patent ID: 7427774

Claim:
A test structure for a semiconductor device, comprising: at least one grating, the grating comprising a plurality of parallel lines, each of the plurality of parallel lines having a first length, wherein each line is divided into a plurality of discrete segments along the first length of the line, wherein the segments of the lines comprise varying dimensions, wherein segments in adjacent lines are staggered in the direction parallel to the first length of the plurality of parallel lines, and wherein the plurality of parallel lines comprises a first line and at least one second line parallel to the first line, wherein the first line comprises a first segment and at least one second segment, the first segment and second segment comprising different lengths, wherein the at least one second line comprises a third segment and a fourth segment, the third segment and the fourth segment comprising different lengths, wherein the first segment of the first line is proximate the third segment of the at least one second line, wherein a first end of the first segment is not aligned with a first end of the third segment, wherein a second end of the first segment is not aligned with a second end of the second segment, wherein the second segment of the first line is proximate the fourth segment of the at least one second line, wherein a first end of the second segment is not aligned with a first end of the fourth segment, and wherein a second end of the second segment is not aligned with a second end of the fourth segment.