Deep electron traps in n-type material, which were introduced by H2 plasma treatments and/or by annealing, were studied by means of isothermal capacitance transient spectroscopy. Electron traps at Ec-0.51eV, Ec-0.34eV and Ec-0.54eV, which were designated by E2, E3 and E4 respectively were found at, and near to, the surface. When the samples were treated with H2 plasma, only E2 traps were detected while E4 traps were entirely passivated with H. Isochronal annealing of He plasma-treated samples revealed a first-order process in the case of E2, with an activation energy and attempt frequency of 1.5eV and 3.2 x 1014/s, respectively. The thermal dissociation energy of H from E4 traps and the attempt frequency were estimated to be 1.65eV and 4.9 x 1013/s, respectively. None of these traps were detected in samples that had been treated with PH3 plasma.

Y.Sakamoto, T.Sugino, K.Matsuda, J.Shirafuji: Materials Science Forum, 1995, 196-201 1973-8