Trapped positive charge in plasma-enhanced chemical vapor deposited silicon dioxide films

We report an investigation of trapped positive charge in as-fabricated plasma-enhanced chemical vapor deposited SiO2 films using electrical and spin resonance techniques. We show that the positive charge results from donor-like ‘‘slow’’ interface states (‘‘anomalous positive charge’’) rather than trapped holes, and that most (∼95%) of the positive charge is not related to E′ centers. The positive charge is similar to that seen in electron-injected thermally grown SiO2, and unlike radiation-induced trapped holes.