The diffusion of Sb at concentrations which were close to its solid solubility was studied by using iso-concentration experiments. The samples were grown, by using molecular beam epitaxy, so as to have a constant 121Sb background doping and a 123Sb spike within this background. Diffusion was then monitored as a function of the Sb background concentration, at 872 and 1019C (figure 6), by means of secondary ion mass spectrometry, differential Hall resistometry and transmission electron microscopy. Interstitial-type dislocation loops and Sb precipitates were observed at concentrations which exceeded the solid solubility. At these concentrations, the diffusivity decreased with increasing Sb background concentration. At concentrations which were below the solid solubility and the intrinsic carrier concentration, at a diffusion temperature of 1019C, the diffusivity increased with increasing Sb background dopant content. This behavior was explained in terms of mobile Sb2V complexes.

A.N.Larsen, P.Kringhøj, J.L.Hansen, S.J.Shiryaev: Journal of Applied Physics, 1997, 81[5], 2173-8