A model of P clustering during high-concentration diffusion in Si was proposed and analyzed. The main feature of this model was the assumption that negatively charged P clusters could be formed. The formation of singly negatively charged clusters incorporating one P atom and two P atoms was investigated. To compare the model with the experimental data the total P concentration, concentration of clustered impurity atoms, and electron density depending on the concentration of substitutionally dissolved P atoms were calculated for both cluster species. Consideration of clusters with negative charge makes it possible to explain the appearance of “plateaux” on the charge carrier profiles obtained at high concentration P diffusion. The parameters describing P clustering at 920C were extracted from fitting the calculated values of the electron density to the experimental data.

A Model of Clustering of Phosphorus Atoms in Silicon. O.I.Velichko, V.A.Dobrushkin, L.Pakula: Materials Science and Engineering B, 2005, 123[2], 176-80