We report a quantitative theoretical and experimental analysis of strain relaxation in GexSi1-x/Si(110) heterostructures. It is shown that above a critical composition, the critical thickness for edge a/6〈112〉 Shockley partial dislocations is less than that for 60°a/2〈110〉 total dislocations. The net (excess) stress is greater on the edge a/6〈112〉 dislocations for epilayer thicknesses, h<hx, but greater on the 60°a/2〈110〉 dislocations for h≳hx. The sensitive calculated dependence of hx upon the stacking fault energy per unit area γ allows an experimental determination of γ=65±10 mJ m-2 for x∼0.3 in Ge xSi1-x.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)