Nitrided Gate Dielectrics and Charge-to-Breakdown Test

In this paper, the applicability of the charge-to-breakdown test for characterisation and comparison of differently grown ultra-thin gate dielectric films is considered. It is shown that the charge-to-breakdown parameter cannot be reliably used, because it is related to the electrons tunneling through the film, and not to the mechanism of positive charge accumulation which leads to time-dependent breakdown. It is found that the constant-voltage stress provides a consistent set of stress field vs time-to-breakdown data. Nitrided gate dielectrics show improved breakdown characteristics, compared to standard silicon-dioxide films.