A method based on the hydrogen/deuterium isotope effect is proposed to separate and quantify the effects of interface trap creation and oxide charge trapping on hot-carrier-induced degradation in n-channel metal-oxide-semiconductor field-effect transistors (MOSFETs). Hydrogenated and deuterated transistors were subjected to hot-carrier stress with a fixed drain voltage Vds and various gate voltages Vgs. The threshold voltage Vl and interface trap density Nit were recorded as a function of stress time. It is found that at low Vgs stress when equal numbers of interface traps are created, the shift of Vl is larger in hydrogenated transistors than in deuterated transistors. Increasing Vgs to 1/3Vds produces no noticeable difference of Vl shift in these two kinds of transistors. However, further increasing Vgs results in larger Vl shift in deuterated transistors than in hydrogenated ones. From a quantitative analysis, the contribution of oxide charge trapping to Vl shift is separated from the contribution of interface trap creation. The results suggest that interface trap creation is the dominant mechanism for hot-carrier-induced degradation in n-channel MOSFETs.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)