ELECTRICAL-PROPERTIES OF SB IMPLANTED SI1-XGEX ALLOY LAYERS

Electrical properties of Sb implanted strained Si1-xGex alloy layers are reported. Two sets of Si1-xGex epilayers with compositions of x = 0.08 and 0.18, MBE grown on (100)Si substrates, were implanted at room temperature with Sb+ ions at energies of 200 and 100 keV, respectively, and doses of 10(13) and 10(15) cm2. Secondary-ion mass spectrometry and spreading resistance profiling measurements show that Sb implantation, with a dose below the critical value for amorphization (10(13) cm-2), formed a p-type region upon annealing at 500-degrees-C. temperature anneals transformed the implanted layer into the expected n-type doping. Maximal values of electrical activity (45 +/- 10%) and mobility were obtained in this case only at temperatures around 800-900-degrees-C. For the high dose implantation (10(15) cm-2 ), it was found that the highest activation efficiency at the implantation profile peak was obtained at 500-600-degrees-C, while at the end-of-range region the activation efficiency was very low.