Oxidation related particles on GaSb (100) substrate surfaces

Oxidation layer and particles on polished and epi-ready cleaned surface of GaSb (100) wafers have been investigated and analyzed by surface scanner KLA candela, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) measurements, respectively. From a large quantity of statistical results, most of the particles are related with the oxides of gallium and antimony. GaSb wafers from upper position of a single crystal ingot exhibits a high surface reactivity with the characteristics of being oxidized easily and more particles left on the surface. After the standard wafer clean process, more particles are detected on the wafer surface from this ingot region, implying a correlation between native gallium antisite acceptor concentration (electrical compensation) and particle adhesion by a combination of SEM, XPS and PL results. The key role of the oxide layer composition, Ga-rich property and the defect states in producing oxidation and particle adhesion behavior has been discussed.