RADIATION EFFECTS IN SILICON AND GERMANIUM

The report describes several related studies of radiation effects in silicon and germanium. Theoretical studies have been performed of recombination behavior at disordered regions and of the influence of traps on steady-state lifetime. These studies apply whether the defects are introduced by irradiation or not. The dependence of steady-state lifetime on excess density was used extensively in experimental studies to determine recombination parameters. In conjunction with measurements of the temperature behavior of lifetime at low excess density, these studies were used to obtain the parameters of recombination centers in n-type germanium irradiated with Co60 gamma rays, and n-type silicon irradiated with 10 -MeV electrons. An experimental study of short-term annealing in bulk silicon indicates that a smaller fraction of the damage is stable in 14-MeV neutron irradiated material than in that irradiated with fission neutrons. (Author) See also Final Report for 1967, AD-666 220.