Assessment of residual subsurface polishing damage in InP wafers by photoluminescence

Abstract

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 μm) and good depth resolution (< 10 nm). The polishing damage was directly observed with the damage extending to a depth of ∼ 50 nm, however there was also a “good” zone extending to a depth of ∼ 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.