SIMS investigations into the effect of growth conditions on residual impurity and silicon incorporation in GaN and AlxGa1-xN

We have investigated the effect of metal-organic chemical vapour deposition growth conditions on impurity incorporation in GaN and AlGaN. Secondary io n mass spectrometry depth profile analyses were performed on GaN and AlGaN wafers with multiple layers in which temperature, V/III ratio, growth rate, carrier gas, Al content, and Si doping were varied. Trends in oxygen, carb on, and silicon concentrations were studied. Similar trends were observed f or both GaN and AlGaN. Growth temperature, composition and V/III ratio had the largest effect on impurity incorporation. Silicon and oxygen incorporat ion were less susceptible to growth conditions than that of carbon.