Phosphorus Isoconcentration Diffusion Studies in Silicon

32 P‐concentration profiles were obtained of diffusions conducted in intrinsic and extrinsic silicon, employing isoconcentration conditions for the latter. All diffusions were conducted in evacuated closed quartz capsules at diffusion temperatures ranging from 950° to 1200°C. The temperature dependence of phosphorus diffusivity in intrinsic and extrinsic silicon is described by the empirical equations D int = 5.3 exp ( − 3.69 eV / kT ) cm 2 / sec and D ext = 0.39 exp ( − 3.12 eV / kT ) cm 2 / sec , respectively. The phosphorus diffusivity is seen to increase about a factor of 10 over the value obtained in intrinsic silicon for the highest phosphorus concentration employed. The results are explained by assuming the diffusion process of phosphorus into silicon is primarily controlled by monovacancies in the single negative charged state.