LIFETIME IN PROTON-IRRADIATED SILICON

Deep energy levels caused by high-energy low-dose proton irradiation o f both n- and p-type silicon have been investigated. Energy positions in the band gap, capture coefficients, and their temperature dependenc es for majority and minority carrier capture and entropy factors have been measured by deep level transient spectroscopy. Computer simulatio ns have been employed to obtain the correct numbers of injected charge carriers needed for the evaluation of minority carrier capture data. From these measurements, it is possible to deduce the charge carrier l ifetime profiles in proton irradiated n-type silicon for different inj ection concentrations and temperatures. At room temperature and for lo w injection, it is found that the singly negative divacancy level with a band-gap enthalpy of H-C-H-T=0.421 eV has the largest influence on the lifetime. At high injection, the vacancy-oxygen center, H-C-H-T=0. 164 eV, is mostly responsible for the lifetime reduction. (C) 1996 Ame rican Institute of Physics.