Depth resolved carrier lifetime measurements of proton irradiatedthyristors

摘要

Depth-resolved carrier lifetime profiles of proton-irradiatedthyristors have been derived using a noncontact, optical pump/probemethod. The results show that the depth distribution of recombinationcentra is sharply peaked at the ion range, although a significant tailextends towards the surface. Thus, the derived profiles exhibit analmost one-to-one correlation to the proton vacancy production rate.Furthermore, the lifetime in the tail scales inversely with ion fluence.Annealing studies, comparing the decrease in the rate of recombinationat increasing temperature with deep level transient spectroscopy (DLTS)measurements, further support the notion that active recombinationcentra, produced by the proton irradiation, are mainly vacancy related.The annealing studies show that active recombination centra arerelatively stable up to ~150° C and only a 10-30% reduction occurs upto 300° C