Ultra-thin oxide reliability for ULSI applications

In this article, we critically examine the limit of gate oxide scaling from a reliability point of view. The thickness dependence of the characteristi c breakdown time (charge) and Weibull slope as well as the temperature depe ndence of oxide breakdown are measured with emphasis on accuracy. The failu re modes of soft and hard breakdown events and their impact on device chara cteristics are reviewed. Using a two-dimensional reliability analysis, we e xplore the relative importance of characteristic breakdown time and Weibull slope in lifetime projection, and the possibilities of extending gate oxid e beyond the currently predicted limit.