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. (C) 1996 American Institute of Physics.