Characterization of processing-induced defects in high-purity InP by photoluminescence

Low‐temperature photoluminescence experiments were performed on high‐purity InP substrates as a function of heat treatment, flat‐profile ion implantation and subsequent annealing procedures. Whereas the well resolved near band edge luminescence proved the superior substrate quality, up to 6 sharp luminescence lines (some of them not reported so far) and one shallow broad‐band emission were observed after Si3N4 deposition and various annealing procedures. From the temperature dependence of the luminescence peak intensities the activation energies of the novel lines were determined and discussed in terms of excitons bound to processing‐induced complex defects. These assignments are supported by the observation of a strong enhancement of the luminescence after low dose Ar+ ion implantation.