Dynamic modeling of Si(100) thermal oxidation: Oxidation mechanisms and realistic amorphous interface generation

Silicon together with its native oxide SiO$_2$ was recognized as an outstanding material system for the semiconductor industry in 1950s. In state-of-the-art device technology, is widely used insulator combination high-$k$ dielectrics such HfO$_2$, demanding fabrication of ultra-thin interfacial layers. The classical standard model derived by Deal and Grove accurately describes oxidation Si a progressed stage, however, strongly underestimates growth rates thin Recent studies report variety mechanisms during films range \SI{10}{\angstrom} various details still under debate. This paper presents first-principles based approach to theoretically assess thermal process technologically relevant Si(100) surfaceduring this initial stage. Our investigations from chemisorption single O$_2$ molecules onto $p(2\times2)$ reconstructed surface oxidized layers thickness up \SI{20}{\angstrom}. initially observed enhanced rate assigned barrierless events upon which oxygen molecule dissociate. We present strong evidence immediate amorphization layer onset oxidation. Surface reactions dominate until saturated separated substrate \SI{5}{\angstrom} transition region. becomes inert dissociative enables diffusion molecular \interface interface assumed within Deal-Grove model. Further then provided dissociations at due same charge transfer responsible surface.