Low Phosphorus Concentrations in Si by Diffusion from Doped Oxide Layers

The diffusion of phosphorus into silicon from doped oxide layers, deposited at low temperatures, has been studied in order to achieve reproducible impurity distributions with surface concentrations varying from 5 × 10¹⁵ to 10¹⁸ atoms/cm³. Special attention has been given to the differences arising from indiffusion in an Formula or in an Formula ambient. The dependence on the temperature of the diffusion coefficients of phosphorus in silicon and in silicon dioxide is determined at a surface concentration of 5 × 10¹⁶ atoms/cm³.