Formation processes of radiation defects in silicon at high temperature irradiation

Full text: This work devoted to research on influence of high-temperature nuclear irradiation in the range of 100† 600oC on the electrophysical and recombination parameters and characteristics of the doped silicon and structures based on it. For studies of defect states, stimulated by nuclear irradiation and temperature, and revealing optimal regimes and conditions for thermo radiation modification and stabilization of parameters of the doped silicon and silicon structures the special electrical-heating setup with sells for samples to be processed by radiation and thermal fields was fabricated. It was studied influence of irradiation temperature on RD generation process in diodes based on n-Si with initial resistivity of 0.3 † 40 Ω· cm. The high-temperature (350 † 450oC) electron irradiation with energy of 4 MeV and fluences of 1015 † 1016 cm-2 and 60Co γ -ray irradiation with fluences of 1017† 1018 cm-2, unlike low-temperature ( ≤ 200oC) irradiation regime, leads mainly to thermally stable defects centers of complex and acceptor nature: Ec - 0.13 eV, related with the formation of (V-O3) complex, Ec - 0.20 eV, related with the complex of substitutional carbon with interstitial oxygen (Cs-Oi-Cs) and Ec - 0.35 eV, related with a complex of carbon, oxygen and vacancy. Theoretical analysis of recombination processes in silicon with defect centers was curried out by Shockly-Readley theory and it was shown that the dominant recombination center is Ec-0.35 eV, which enables one to regulate in a wide range recovery time of diodes. The measurements of current and time characteristics of silicon diffusion diodes revealed that the high-temperature radiation treatment of p-n-structures improves values of recovery time of reverse resistance and direct voltage with simultaneous enhancing stability of characteristics of diodes against temperature as compared to low-temperature (<200oC) radiation treatment. This work was supported by the STCU grant Uzb-32(J)R