Assessment of residual subsurface polishing damage in InP wafers by photoluminescence

The polishing damage present in as-polished (100) LEC S-doped InP wafers has been investigated using the ''photoluminescence on chemically angle-polished surfaces'' method. The technique was shown to have good lateral resolution (< 2 mu m) and good depth resolution(< 10 nm). The polishing damage was directly observed with the damage extending to a depth of similar to 50 nm, however there was also a ''good'' zone extending to a depth of similar to 10 nm where no damage was observed. The photoluminescent damage contrast was interpreted as arising from dislocations and cracks. The damage amount and distribution were different in the wafers examined.