Mechanism for anneal‐induced interfacial charging in SiO2 thin films on Si

H‐induced positive charging is observed at both the top Si/SiO2 and bottom SiO2/Si interfaces in Si/SiO2/Si structures. The response of the H‐induced positive charge to thermal annealing and electron injection is very different from that of simple oxygen vacancy hole traps in SiO2. To explain this H‐induced positive charging, we propose a scheme in which H reacts to form positively charged over‐coordinated oxygen centers in close proximity to both top and bottom interfaces. The annealing‐induced entity may also provide a natural explanation for the origin of the fixed oxide charge that forms during oxidation of Si.