What are the techniques to detect micro cracks in Si wafers. Preferably for a bunch of wafers together. I know EL/PL is one technique but it is for individual wafer not a bunch of wafers together.
Dear colleague! There are some commercial systems to check cracks by ultra-sound-based techniques (Netherland) providing a Yes/No Information for the whole wafer. I have known some other projects where the cracks in mono-material could be identified by scanning with a laser vibrometer analysing the sound figures and frequency characteristic. If you want to study polished wafers you should use optical imaging techniques as our SIRD (Scanning Infrared Depolarization Imager). SIRD is world-wide used for fast in-line wafer evaluation, in particular of wafer edges. The strength of our method is that we can reveal the stress fields of buried defects as emerging cracks. Wkr, M. Herms.
ultrasound is used for in-line check. Here is a link to a company that makes commercial systems:
http://www.ultrasonictech.com/index.html
Thanks Mr. Dutta. Have you previously used DIC microscopy for crack detection purpose for wafers.
Or you can even observe it by using Referenced Spectroscopic ellipsometry (RSE) its a new built system from Accurion, which works with a reference wafer.
Best regards
Christian
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Thin Films and Nanotechnology