Résumé
During the process of elaboration of n+ /p InP photodiodes for solar energy conversion, we have observed that the 700 C sulfur diffusion into Zn doped InP substrates strongly modifies the electrical and photoelectrical properties of these substrates. A simple annealing at the same temperature produces nearly equivalent effects. The most relevant modification is a strong, depth independent hole density increase (more than one order of magnitude). A degradation of the photoelectrical parameters : diffusion length L and carrier lifetime τ has also been detected near the surface of the heat treated substrates. The deep traps measured from deep level transient spectroscopy (DLTS) are not typical of the heat treatment.