Comparative Study of Carrier Lifetime Variations with Doping in Si and Ge

Abstract

The joint application of Si and Ge in advanced devices is the motivation for a comparative study of the dependence of recombination characteristics on excitation and doping density. Carrier lifetimes measured at high and low excitation levels are compared with simulations varying the excitation level. The Shockley-Read-Hall (SRH) model was combined with Auger recombination above a doping concentration threshold to simulate the observations. The dependence of carrier lifetime on dopant concentration and excitation level shows a very similar behaviour in Si and Ge and can explained well by a combined SRH and Auger recombination model.