Hydrogen-related volatile defects as the possible cause for the recoverable component of NBTI

The recently suggested time-dependent defect spectroscopy (TDDS) has allowed us to study the recoverable component of NBTI at the single-defect level. To go beyond our previous efforts, we have performed a long-term TDDS study covering also the kilo-second time window. We found that even in this extended window NBTI recovery is due to a collection of first-order reactions. In particular, there is no trace of a diffusion-limited process as assumed in the reaction-diffusion model. Most intriguingly, the responsible traps show various degrees of volatility, that is, they can disappear and reappear. Our observations lend strong support to the idea that the recoverable component of NBTI is due to hydrogen-related defects which are active when a hydrogen atom is at the defect site and inactive when not.