The effects of irradiation and proton implantation on the density of mobile protons in SiO2 thin films

The radiation response of mobile protons introduced into thermal oxides capped with poly-Si is investigated. Total dose irradiation data show that the cross section for capture of radiation-induced electrons by mobile protons is two orders of magnitude smaller than for electron capture by trapped holes. A consistent model is proposed to explain the weak temperature dependence of the capture process observed in this study as opposed to the strong increase in proton neutralization with increasing temperature observed in an earlier UV exposure study. In contrast with the behavior of SOI material, no post-irradiation trapping of mobile protons could be observed in the thermal SiO₂ layer of the Si/SiO₂/Si structures studied in this work. In the second part of this work it is shown that, unlike the effect of annealing in a hydrogen containing ambient, proton implantation does not yield a significant number of mobile protons in the buried oxide of Si/SiO₂/Si structures