Wafer metrology pattern integrating both overlay and critical dimension features for SEM or AFM measurements

摘要

The present invention provides a wafer metrology pattern integrating both overlay and critical dimension features for SEM or AFM measurements. The present invention provides an improved test mask target which contains lines measuring 0.25 &mgr;m, 0.3 &mgr;m, and 0.5 &mgr;m. The spaces between the lines can be adjusted accordingly. The improved test mask target provides a pattern that combines the wafer critical dimension and box-in-box overlay targets into a single structure. As a result, the pattern may be used for both overlay and critical dimension verifications in a single AMF or SEM measurement. More precisely, wafer overlay and critical dimension disposition may be made simultaneously, reducing the need to perform multiple measurements at each testing step.