Controlling misfit dislocation generation in strained layer epitaxy by point defect injection

摘要

A detailed study on the evolution of dislocations has been conducted on Ge_xSi_(1-x)/Si heterostructures during rapid thermal anneals (RTA) of 540 keV self-irradiated Si versus s-grown samples. The implant fluence of 2 x 10~(14) ions/cm~2 and a substrate temperature of 25 deg C were used for these experiments. Nomarski interference microscopy has been used to quantitatively examine the behaviour of misfit dislocation generation. Dislocation densities were reduced by as much as an order of magnitude in the implanted samples relative to the as-grown material. Secondly, nucleation rates were reduced significantly following implantation. These results have been interpreted in terms of a point defect-controlled misfit dislocation nucleation mechanism.