Charged particle activation analysis for carbon,nitrogen and oxygen in semiconductor silicon

Convenient processes are described for the charged particle activation analysis for carbon, nitrogen, and oxygen in semiconductor silicon. Suitable activation reactions and incident particle energies were selected, and the interferences examined; the activation curves for the Si+³He→¹¹C and Si+³He→¹⁸F reactions, which may seriously interfere with³He activation analysis, were measured, and the interference caused by the fission of the matrix itself is discussed. A simple technique for the separation of¹¹C present in silicon is proposed. Reliable determination of as low as several parts per billion of the three elements has thus become possible. Semiconductor silicons of various origin were analyzed for C, N and O, and the behaviour of these elements during zone-melting is reported.