Defect States in Silicon Nitride

The energy levels of defect centers in amorphous silicon nitride have been calculated. The results are related to recent photoemission and light-induced electron spin resonancedata. The Si dangling bond is argued to be the memory trap in MNOS devices and to be responsible for the electron accumulation at interfaces with amorphous silicon and for the n-type chargetransfer doping of amorphous silicon-silicon nitride superlattices.