Advances in positron annihilation spectroscopy of Si, Ge and their alloys

Studies on vacancy defects in Si, SiGe and Ge with positron annihilation spectroscopy are reviewed. The E-centers involving As and Sb in Si are identified and their thermal stability is studied in annealing experiments. In SiGe the influence of Ge on both the thermal stability of the E-center and its effect on the charge transitions of the E-center is reviewed. The positron annihilation specific defect parameters are determined for the divacancy and the monovacancy in Ge.