Subthreshold defect production in silicon

An investigation of radiation effects in p-type silicon under X radiation in the subthreshold energy range is presented. This irradiation causes an appreciable decrease of the hole concentration which is stable at 80 K. The decrease of the hole concentration Δp = p0-p versus irradiation dose phi is non-linear. It is found that the hole-removal rate Δp/phi is independent of the initial hole concentration in the range p0=2 x 1013 to 2 x 1014 cm-3 under X irradiation up to integral fluxes of phi = 1017 cm-2. The results permit to assume that under low temperature X irradiation close Frenkel pairs were generated which annihilate without complex production. Dependence of the defect production cross-section on carrier concentration is calculated and plotted according to experiments