Defect Interactions of ${\hbox{H}}_{2}$ in ${\hbox{SiO}}_{2}$: Implications for ELDRS and Latent Interface Trap Buildup

The energetics of the interactions between molecular hydrogen and common defects in SiO₂ that are typically associated with O deficiency have been obtained using atomic-scale quantum mechanical calculations. H₂ does not easily crack at neutral vacancies, but it will crack efficiently at O vacancy sites that have captured a hole and relaxed into the puckered configuration of an E_γ^' defect, releasing a proton into the oxide. Isolated Si dangling bonds also can play a role in cracking H₂, depending on their concentration in the oxides. These results provide significant insight into the underlying causes of latent interface trap buildup in MOS devices and enhanced low-dose-rate sensitivity in linear bipolar devices.