Advanced Modeling of Oxide Defects

During the last couple of years, there is growing experimental evidence which confirms charge trapping as the recoverable component of BTI. The trapping process is believed to be a non-radiative multiphonon (NMP) process, which is also encountered in numerous physically related problems. Therefore, the underlying NMP theory is frequently found as an important ingredient in the youngest BTI reliability models. While several different descriptions of the NMP transitions are available in literature, most of them are not suitable for the application to device simulation. In this chapter, we will present a rigorous derivation that starts out from the microscopic Franck-Condon theory and yields generalized trapping rates accounting for all possible NMP transitions with the conduction and the valence band in the substrate as well as in the poly-gate. Most importantly, this derivation considers the more general quadratic electron-phonon coupling contrary to several previous charge trapping models. However, the pure NMP transitions do not suffice to describe the charge trapping behavior seen in time dependent defect spectroscopy (TDDS). Inspired by these measurements, we introduced metastable states, which have a strong impact on the trapping dynamics of the investigated defect. It is found that these states provide an explanation for plenty of experimental features observed in TDDS measurements. In particular, they can explain the behavior of fixed as well as switching oxide hole traps, both regularly observed in TDDS measurements. abstract on a separate page so as not to break the formating of the chapteron a separate page so as not to break the formating of the chapter Advanced Modeling of Oxide Defects Wolfgang Goes, Franz Schanovsky, and Tibor Grasser