STRUCTURAL-PROPERTIES OF GE-IMPLANTED SI1-XGEX LAYERS

The structural properties of epitaxial Si1-xGex layers formed by high- dose germanium implantation have been studied. Transmission electron m icroscopy (TEM) and Rutherford backscattering channeling (RBS-C) were employed to evaluate the annealing behavior of radiation damage. The d epth profiles of impurities and dopants of O, C, F, and Ge were measur ed by secondary-ion mass spectroscopy (SIMS). Defect-free epitaxial re growth through rapid thermal annealing (RTA) at 1100 degrees C for 10 s was observed for the silicon layer implanted by 50-keV Ge+ ions. How ever, a great number of end-of-range (EOR) dislocation loops were left with the same RTA process when the silicon layer was implanted by 100 -keV Ge+ ions. The EOR damage density was considerably reduced with an increase in the RTA time; consequently, dislocation defects disappear ed after RTA at 1100 degrees C for 200 s. This was confirmed by TEM. F urther SIMS studies showed that out-diffusion of impurities of O, C, a nd F towards surfaces was accompanied by a reduction of residual EOR d amage.