Using rapid thermal processing (RTP), films with a thickness of 35 nm were annealed in and subsequently reoxidized. The properties of charge trapping and interface state generation of these films were investigated by an avalanche hot‐electron injection technique. Experimental results indicate that by reoxidation, both the density of annealing induced traps and their capture cross section can be reduced; the hardness of the interface against hot‐electron bombardment is improved while the low oxide fixed charge and interface state density as well as the high breakdown field are also preserved. A correlation between the interface state generation and the history of thermal nitridation is observed. Results also show that rapid thermal annealing induced traps must be water related and have a much smaller capture cross section than that of the conventionally nitrided oxide. It is proposed that hydrogen dissolved from during nitridation introduces defects in the form of unsaturated Si‒O bonds which may be responsible for the high density of electron traps while the interface‐incorporated nitrogen will help to increase the resistance to the hot‐electron injection induced damage. An oxygen deficiency model can be used to explain the origin of these traps as well as the generation of interface states and the mechanism of reoxidation.
No takes yet. Share an insight, caveat, or question.
Liu et al. (1990) studied this question.