A Model of High-Concentration Phosphorus Diffusion in Silicon with Account for Crystal Lattice Deformation and Formation of Negatively Charged Clusters

Abstract

A comprehensive model of high-concentration phosphorus diffusion has been developed and numerical calculations of phosphorus diffusion from a constant source (phosphosilicate glass) at a temperature of 890 C for 9.25 min have been done. Such doping processes are widely used in manufacturing modern solar cells. The proposed model combines the ideas of the drift of silicon self-interstitials in the field of elastic stresses with the concept of the formation of negatively charge clusters of impurity atoms. The model explains all specific features of high-concentration phosphorus diffusion. The calculated phosphorus concentration profile is in good agreement with the experimental one confirming the adequacy of the model proposed.