Accumulation of radiation defects in oxygen-rich n-type silicon heat-treated at temperatures from 600 to 1000 0C

Both,changes in the states of oxygen and carbon impurities in silicon due to heat treatments within a temperature range from 600 to 1000 0C and the efficiencies of radiation defect formation under electron irradiation in as-grown and heat-treated materials are investigated using IR-sectroscopy, DLTS, and Hall-effect measurements. In phosphorus-doped silicon the removal rate of free electrons is found to decrease as a result of preliminary heat at 900 0C. Comparison with the results obtained on accumulation of deep level centers suggests that the above effect is caused by a decrease of the production rate of compensating acceptor defects with the levels in the lower half of the forbidden gap or by an increase of the efficiencies of sinks for silicon self-interstitials, interaction of which with phosphorus donors causes electrical compensation of the material after irradiation. (author)