The diffusion of Cu in Si-doped material was studied. Photo-induced current transient spectroscopic techniques were used to identify deep levels in Si-doped Cu-compensated material. The effect of capping the deposited Cu layer during the diffusion of Cu in Si-doped material was studied by obtaining photo-induced current transient spectra at various depths from the sample surface. A concentration gradient of the energy levels of Cu-associated complexes was found to exist into the depth of the diffused sample. This was to be expected, because the formation of the VAsCuGaVAs complex, which was considered to be responsible for the CuB level, was favored by an increase in the concentration of VAs.

L.M.Thomas, V.K.Lakdawala: Defect and Diffusion Forum, 1993, 95-98, 931-6