Polishing, chemical etching and thermal treatment effects on surface and electrical properties of Er and Nd-doped GaSb substrates

In this work several changes induced by polishing, chemical etching and thermal treatment in the properties of Er- and Nd-doped GaSb substrates with different doping levels grown by the vertical Bridgman method have been studied. The analysis has revealed the formation of precipitates at the highest doping levels for both Er- and Nd-doped GaSb. Cathodoluminescence analysis shows the reduction of the defect band induced by the rare earth (RE) elements. For high dopant concentrations the precipitation phenomena reduce this effect. Thermal treatments have produced an enhancement of the p-type properties of the samples. For a dopant density of 2×1019 cm−3 this effect is more pronounced.