Our photoluminescence system is capable of imaging a full 6 inch square silicon wafer in a matter of seconds. We use the imaging photoluminescence in conjunction with the Sinton Lifetime Tester to map defects across the wafer. For instance, in the sample below the wafer on the left has extensive surface damage and surface residue after etching. The sample on the right show the same process after optimization of the etch process.
Appearance of a wafer with multiple defects. The dark regions have low photovoltaic response
After optimizing the etch process we have good uniformity across the whole wafer