INTERFACE TRAPS CREATION BY SUBBAND GAP IRRADIATION IN SILICON DIOXIDE ON SILICON WITHOUT APPLIED ELECTRIC-FIELD

The effective recombination lifetime of thermally oxidized silicon waf ers is found to vary little following 4.2 eV ultraviolet irradiation b ut decrease dramatically when the photon energy is elevated up to 4.9 eV, indicating generation of the interface traps, This finding is disc ussed with the model of the hot-electrons induced hydrogen redistribut ion in which about 2 eV energy is necessary for the electrons in the o xide conduction band to liberate a trapped hydrogen atom and generate in turn interface traps. It is stressed, however, that if the model is true the release of hydrogen atoms trapped inside the oxide should be , at least partly, responsible for the generation of interface traps b ecause the samples used in this article are gate-free. (C) 1996 Americ an Institute of Physics.