The interdiffusion in SiGe(C)/Si(C) superlattice structures having differing positions and concentrations of substitutional C atoms was studied under ambient or high hydrostatic pressures, at 700 to 950C. The Ge (about 20%) and C (0 to 0.5%) concentrations were typical of those found in devices. The coefficient of Si/Ge interdiffusion increased linearly with C concentration, and with the total amount of C in the superlattice structure. A further increase in the diffusivity was observed with increasing hydrostatic pressure. Both effects were explained in terms of a modification of the point-defect spectrum, with regard to an under-saturation of Si self-interstitials and a supersaturation of vacancies.

The Influence of Substitutional Carbon on Si/Ge Interdiffusion Studied by X-Ray Diffractometry at Superlattice Structures P.Zaumseil: Journal of Physics D, 1999, 32[10A], A75-80. See also: Solid State Phenomena, 1999, 69-70, 203-8