The diffusion of P from a POCl3 source and into (111)-oriented n-type single crystals was studied by using sectioning via anodic oxidation, and 4-point resistivity techniques. The P transport was controlled by 2 diffusing species; characterized by 2 appreciably different diffusion coefficients. The slow-diffusing component was present mainly in the transition region between the phase boundary and the fast-diffusion dominated region. The fast-diffusing component exhibited a maximum concentration at the phase boundary. The diffusivity at 820 to 1100C in the 2 cases could be described:
fast: D (cm2/s) = 2.49 x 10-5 exp[-2.0(eV)/kT]
slow: D (cm2/s) = 4.93 x 101 exp[-3.77(eV)/kT]
As the diffusion temperature was increased, the diffusion constants for slow and fast diffusion approached each other. At 1100C, the diffusion profile could be represented by a single diffusion constant.
J.C.C.Tsai: Proceedings of the IEEE, 1969, 57[9], 1499-506