Diffusion of Ge in Si1-xGex/Si single quantum wells in inert and oxidizing ambients

The interdiffusion of Si/Si0.85Ge0.15/Si single quantum well (SQW) structures subjected to inert- and oxidizing-ambient annealing was investigated as a function of temperature (900-1200 degrees C) and time. Point defect injection allowed modification of the vacancy and interstitial mediated components of interdiffusion, D-V and D-I. Diffusion profiles of samples processed in inert and oxidizing ambients were similar, which indicates a vacancy-dominated mechanism. Activation energies of diffusion in inert and oxidizing ambients were found to be 5.8 and 5.0 eV, respectively. A fractional interstitial component f(I) of similar to 0.10 was estimated for the lower temperatures, while a significantly smaller f(I) of similar to 0.02 was estimated for the higher temperatures. Experiments using SQWs with buried boron marker layers showed that dislocations in the Si1-xGex trap point defects and affect interdiffusion behavior. (C) 2000 American Institute of Physics. [S0021-8979(00)05015-5].