Structure of the breakdown spot during progressive breakdown of ultra-thin gate oxides

Abstract

The structure of the breakdown spot during progressive breakdown (BD) of ultra-thin gate oxide was studied. The nMOSFETs were stressed at +4V. To study the physical structure of the BD spot during progressive BD, it is important to perform the analysis on small geometry devices, to facilitate the TEM analysis. It was shown that the progressive BD is the dominant BD mode under conditions in CMOS circuits. The MOSFET devices were subjected to accelerated stresses at constant voltage in inversion at room temperature.