Sometimes it is difficult to find a good site alignment feature when inspecting a featureless area such as a large die at high magnification or a vast array such as memory or bumps.  System misalignment often leads to false defect detections and/or lowered defect sensitivity.   Rudolph Technologies has been developing and improving our site alignment techniques for the past six months and has successfully field tested the new algorithms at multiple customers.  These new techniques have been formally released in XFrontside 3.2.1. 

Below is an example of high magnification false defect defections on a bump array. The wafer map on the left is from 3.2;  the wafer map on the right was inspected with 3.2.1.  After the recipe site alignments were modified utilizing the new techniques, all false alignment defects were eliminated. In addition to improvements in automatic site alignment selection and performance, the software also provides visual cues for improved manual selection.

If you would like to know more about XFrontside 3.2.1, please let us know – email info@rudolphtech.com