The dopant was diffused into (111) single crystals, having dislocation densities of less than 500/cm2, under intrinsic vacuum-sealed tube conditions. It was found that low-concentration migration of the dopant from the vapor phase and into the bulk was markedly affected by a surface rate-limiting process. The diffusion data for 1100 to 1250C could be described by:
D (cm2/s) = 2.03 x 101 exp[-3.87(eV)/kT]
R.N.Ghoshtagore: Solid State Electronics, 1972, 15, 1113-20