Origin of positive charge generated in thin SiO2 films during high-field electrical stress

A study was conducted on the characteristics of electron capture after hot-hole injection into a 131-A silicon dioxide, which was then compared with those after Fowler-Nordheim electron injection. Positive charges were accumulated in the oxide after hole injection from the silicon substrate into the oxide. The low-field electron capture observed may be explained based on the electron tunnelling from the substrate into the positive charge and neutral trap centers created near the substrate-SiO2 interface.