Electrically active defects, in buried layers which had been produced by heavy ion implantation, were studied using conventional deep-level transient spectroscopy and an isothermal spectroscopic technique (time-analyzed transient spectroscopy) that was carried out in constant capacitance mode. It was shown that the latter method was more reliable, than deep-level transient spectroscopy, for the characterization of heavily damaged buried layers. The major trap which was produced in buried layers of p-type material, by MeV Ar+ implantation, was found to have an energy level at Ev+0.52eV. This trap was suggested to be responsible for compensation in damaged layers, and exhibited exponential capture dynamics. An unusually high thermal activation energy for capture was observed, and was attributed to a microscopic energy barrier to carriers reaching the buried layer. Two other majority carrier traps were observed, together with a minority carrier trap that was perhaps due to inversion within the depletion layer.

P.K.Giri, S.Dhar, V.N.Kulkarni, Y.N.Mohapatra: Journal of Applied Physics, 1997, 81[1], 260-3