On interface and oxide degradation in VLSI MOSFETs. I. Deuterium effect in CHE stress regime

This paper analyzes in detail the generation of interface states (N_it) and stress-induced leakage current (SILC) during channel hot electron (CHE) stress experiments in the context of a possible hydrogen/deuterium (H/D) isotope effect. Our results show that N_it generation is related to the hydrogen release (HR) at the Si-SiO₂ interface at relatively high V_G where a large isotope effect is found. Instead, for gate voltages (V_G) favorable for hot hole injection (HHI) the N_it creation becomes a unique function of hole fluence and the isotope effect disappears. In the studied stress conditions, we found no experimental evidence supporting a causal relation between SILC generation and HR because no isotope effect is observed even when the corresponding N_it measurements reveal a very different D/H release rate. Similar to N_it generation, we found that SILC becomes a unique function of hole fluence at low stress V_G. Relevant implications and extensions of these results to the Fowler-Nordheim (FN) tunneling stress conditions are discussed in Pt. II