INTERACTIONS OF DEUTERIUM WITH ION-IRRADIATED SIO2 ON SI

The interactions of deuterium with ion-irradiated SiO2 on Si were investigated during annealing in D2 gas and vacuum over the temperature range 373-1273 K. The uptake and release of D by the oxide layer were monitored using the ion-induced nuclear reaction D(3He,p) 4He. Results were analyzed in terms of a new mathematical model which describes the diffusion of atomic D and molecular D2 in conjunction with trapping at irradiation defects via SiD and OD bonding. The combined body of experimental data on release is quantitatively described by the model using fitted binding enthalpies of 2.8 eV for the Si-D interaction and 3.2 eV for the O-D coupling. The model predicts a relationship between the activation barriers for trapping and detrapping which is in semiquantitative agreement with the experimental data on uptake. The same relationship is obeyed by independently reported results on the hydrogen passivation and reactivation of Si-dangling-bond defects at the SiO2-Si interface.