THE EFFECT OF DIFFERENT TRANSITION METALS ON THE RECOMBINATION EFFICIENCY OF DISLOCATIONS

Abstract
MBE growth of Si_1-xGe_x on (100) Si substrates was used to produce 60° misfit dislocation networks at depths suitable for EBIC investigation. Two different Ge concentrations were used to generate networks of different dislocation density. The effects of different transition metal contaminants on the recombination efficiency of the dislocations has been investigated for the different dislocation density layers. Cu, Fe, Ni, and Cr metallic impurities were diffused into the specimens during a 30 minute anneal at 700°C. EBIC images taken under identical experimental conditions have been qualitatively compared in order to assess the relative effects of each of these contaminants. Results of these investigations have indicated how, in all cases, the addition of metallic impurities increases the electrical activity of the dislocations with differences between the different metals being observed.