OPTIMIZATION OF GE/C RATIO FOR COMPENSATION OF MISFIT STRAIN IN SOLID-PHASE EPITAXIAL-GROWTH OF SIGE LAYERS

In order to study the strain-compensation effect by C atoms in solid phase epitaxial (SPE) growth of SiGe alloy layers, C sequential implantation was performed in [100] oriented Si substrates with various doses after high dose (5 x 10(16)/cm2) Ge implantation. When the nominal peak concentration of implanted C was over 0.55 at. % in the present sample series, misfit dislocation generation in the epitaxial layer was considerably suppressed. A SiGe alloy layer with 0.9 at. % C peak concentration under a 12 at. % Ge peak shows the greatest improved crystallinity compared to layers with smaller C peak concentrations. The experimental results, combined with a simple model calculation, indicate that the optimum Ge/C ratio for strain compensation is between 11 and 22.