Lifetime in proton irradiated silicon

Abstract

Deep energy levels caused by high-energy low-dose proton irradiation of both n- and p-type silicon have been investigated. Energy positions in the band gap, capture coefficients, and their temperature dependences for majority and minority carrier capture and entropy factors have been measured by deep level transient spectroscopy. Computer simulations 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 lifetime profiles in proton irradiated n-type silicon for different injection concentrations and temperatures. At room temperature and for low injection, it is found that the singly negative divacancy level with a band-gap enthalpy of HC−HT=0.421 eV has the largest influence on the lifetime. At high injection, the vacancy–oxygen center, HC−HT=0.164 eV, is mostly responsible for the lifetime reduction.