Breakdown mechanisms in ultra-thin oxides: impact of carrier energy and current through substrate hot carrier stress study

摘要

An experimental investigation of breakdown phenomenon using substrate hot hole and electron stresses of silicon dioxide ranging in thickness from 2 to 5 nm is reported. First, we demonstrate that the scattering effect is responsible of the low activation energy already observed by other authors [J. Appl. Phys. 90(5) (2001)]. Based on a method of carrier energy measurement we characterize the scattering effect. Second, we demonstrate the decorrelation between carrier energy and carrier density showing that the carriers-carriers scattering is negligible. Finally being capable to confirm the real decorrelation between energy and density we observed a current dependence of the charge to breakdown. Besides, we give a theory using the multiple vibrational excitation of the Si-H bound [Surf. Sci. 368-377 (1996); Science 268 (1995) 1590]. Hence, we demonstrate once again that the hydrogen species behavior is strongly linked to breakdown phenomenon.