Post-breakdown characterization in thin gate oxides

摘要

In this paper we investigate soft/hard breakdown statistics and conduction in thin gate oxide (tox = 4nm) N-MOS devices as a function of the stress polarity, geometry and area. We show: (ⅰ) the presence of a new breakdown mechanism with intermediate characteristics with respect to traditional soft and hard breakdown; (ⅱ) the strong dependence of the incidence of the different breakdown modes on stress polarity and device aspect ratio; (ⅲ) the origin of the post soft-breakdown substrate current.