Thermal evolution of vacancy complexes was studied in P-doped ([P] = 1018/cm3) proton irradiated Si1−xGex with Ge contents of 10, 20 and 30% in the range of 250 to 350C using positron annihilation spectroscopy. The radiation damage recovers in the course of anneals but the final state differs from that in as-grown samples indicating the presence of small Ge clusters in the samples, contrary to the initially random Ge distribution. The activation energy for the annealing process was estimated to be 1.4±0.3eV and attributed to the dissociation energy of the vacancy-phosphorus-germanium (V-P-Ge) complex.

Stabilization of Ge-Rich Defect Complexes Originating from E Centers in Si1−xGex:P. S.Kilpeläinen, K.Kuitunen, F.Tuomisto, J.Slotte, H.H.Radamson, A.Y.Kuznetsov: Physical Review B, 2010, 81[13], 132103