Structural properties of Ge-implanted Si 1 − xGe x layers

Abstract

The structural properties of epitaxial Si 1 − x Ge x layers formed by high-dose germanium implantation have been studied. Transmission electron microscopy (TEM) and Rutherford backscattering channeling (RBS-C) were employed to evaluate the annealing behavior of radiation damage. The depth profiles of impurities and dopants of O, C, F, and Ge were measured by secondary-ion mass spectroscopy (SIMS). Defect-free epitaxial regrowth through rapid thermal annealing (RTA) at 1100 °C for 10 s was observed for the silicon layer implanted by 50-keV Ge + ions. However, 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 disappeared after RTA at 1100 °C for 200 s. This was confirmed by TEM. Further SIMS studies showed that out-diffusion of impurities of O, C, and F towards surfaces was accompanied by a reduction of residual EOR damaged.