Energy Levels in Electron-Bombarded Silicon

Electron bombardment of $n$- and $p$-type silicon reduces the lifetime of minority carriers and decreases the carrier concentration. This paper presents evidence that: (a) an electron trapping level is located 0.16 ev below the conduction band and a hole-trapping level 0.29 ev above the valence band, (b) the recombination centers responsible for the reduction of lifetime in $n$-type are located 0.31 ev from a band edge, and those in $p$-type approximately 0.24 ev from a band edge, (c) lattice imperfections are produced at a rate of 0.18 per electron-cm of bombardment at 700 kev.