Recombination and Trapping in Normal and Electron-Irradiated Silicon

Abstract

Both recombination and trapping are observed in normal and irradiated silicon. There combination processes are analyzed on a Shockley-Read model and the energy levels and relative electron and hole capture cross sections of the recombination centers are given. A previously unreported recombination center is produced in $p$-type silicon by electron irradiation. It is located at ${E}_{v}+0.18$ eV and is a net donor. Four samples of $n$-type silicon were studied, three of which gave agreement with the results of Galkin (${E}_{r}={E}_{c}\ensuremath{-}0.17$ eV), and the fourth gave agreement with the results of Wertheim (${E}_{r}={E}_{v}+0.27$ eV). A theoretical treatment of trapping in the presence of direct or indirect recombination is presented and shown to give good agreement with the observed trapping behavior. Three distinct trapping levels are seen in $n$-type silicon.