ION MIXING IN SI/GE LAYERED STRUCTURES

Ion mixing of semiconductor layered structures has been found to exhibit a thermally activated regime and an athermal regime, similar to that observed for metal-semiconductor and metal-metal systems. The kinetics of ion mixing in the Si/Ge system were investigated in this work; the emphasis was placed on the effects of impurities and the mismatch strain on the athermal mixing rate. It was found that the presence of H, Au, W, and O does not affect the ion mixing kinetics between Si and Ge. The athermal mixing rate, however, appears to be significantly affected by the mismatch strain in the layered structure. These results indicate that strain energy plays an important role in biasing the random walk process of mixing.