Si–SiO₂ interface band‐gap transition – effects on MOS inversion layer

Abstract

Abstract Density functional theory simulation results of the atomic structure at the Si–SiO 2 interface implies a non‐abrupt transition of the band‐gap within the oxide. The depth of the transition, 2–6 Å, is comparable to the approximately 1 nm oxide thickness in nano‐CMOS devices, and is expected to affect their characteristics. Using hierarchical simulation approach, we combine for the first time ab‐initio density functional theory simulations of the interface, with self‐consistent Poisson–Schrödinger one‐dimensional device simulations, and estimate the impact of interface band‐gap transition on the inversion layer quantisation, capacitance, and tunnelling characteristics of a metal–oxide–semiconductor structure. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)