A STUDY OF THE INTERACTION OF ELECTRON-BEAM GENERATED EXCESS CHARGE-CARRIERS WITH A SI SIGE/SI HETEROSTRUCTURE/

The recombination properties of a Si/SiGe/Si double heterostructure ha ve been investigated by means of the electron beam induced current (EB IC) technique. Measurements of the EBIC collection efficiency dependen ce on electron beam energy and current have been performed at room tem perature. The results are fitted by a simple model in which the SiGe e pilayer is approximated by a single interface of finite recombination velocity. Interpretation of the results in terms of the Shockley-Read- Hall recombination model, and taking into account the influence of the excess carrier density, suggest the following parameters characterizi ng the SiGe/Si interface: a deep level located near mid-gap with a rat io of capture cross-sections of holes and electrons around 5 and an ar eal density of centres around 5 x 10(13) cm(-2).