Deep-level defects appeared upon heat treating wafers with surfaces that had been disordered by means of mechanical lapping or by introducing high impurity concentrations into diffusion layers. By means of capacitance transient spectroscopy and other methods, it was shown that predominant electron traps - with ionization energies of 0.28 and 0.54eV - exhibited a low recombination activity but affected the resistivity of high-purity material and played a key role in limiting the p-n junction breakdown voltage. A study of the defect parameters revealed their similarity to S-related centres in Si.

E.V.Astrova, V.B.Voronkov, V.A.Kozlov, A.A.Lebedev: Semiconductor Science and Technology, 1998, 13[5], 488-95