Kinetics of Thermal Growth of Ultra-Thin Layers of SiO[sub 2] on Silicon

Abstract

The thermally activated growth of oxide on silicon as a function of time obeys a linear‐parabolic relationship, the linear part of which stems from interface limited reactions. In Part I of this paper, it has been reported that this linear part cannot result from a single rate‐limiting reaction step, because the order of the over‐all reaction rate differs for different substrate orientations at a fixed temperature and varies for a given orientation as a function of temperature. A kinetic model for the reaction between silicon and oxygen at the normalSi‐SiO2 interface is now presented to account for the experimental data false(dnormalSiO2 300Aå,Tnormalox=700°–1000°C,normalpO2=0.01–1.0 normalatmfalse) . Two parallel, competing reactions are postulated to occur. In the first of these, molecular oxygen reacts directly with silicon to form silicon dioxide and atomic oxygen; the second reaction involves the dissociation of O2. The atomic oxygen thus formed, may either react with silicon or recombine to molecular oxygen. An analysis of the data shows that a difference in the activation energies (i.e., 1.91 vs. 0.58 eV) associated with these competing reaction steps is responsible for the shift in their relative importance as a function of temperature.

Growth of thin SiO2 films on clean Si (111) surfaces by low-pressure oxidation and their evaporation

“…This experimentally determined activation energy is in good agreement with the value of 0.58 eV calculated by Ghez and van der Meulen [27] and there was discwssed to be the activation energy of dissociation of 0, at the Si-SiO, interface prior to oxidation. Therefore, according t o [ 2 7 ] , for the low oxidation temperatures as used in our work dissociation of oxygen into atomic species and not reaction of an oxygen molecule with a Si-Si bond should be the dominant reaction process.…”

18O Tracer Study of Si Oxidation in Dry O 2 Using SIMS

“…Redistribution subject to ECS terms of use (see 138.251.14. 35 Downloaded on 2015-03-23 to IP creases sharply across the interface into the silicon bulk. We attribute this slow rise in the ~60-signal and in the 28Si-signal to charging of the surface from ion bombardment uncompensated for in our energy distribution integration.…”

“…ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 138.251.14 35. Downloaded on 2015-03-23 to IP…”

Models for the oxidation of silicon

“…Two interface kinetics models have received attention (54,83). The earlier Ghez and van der Meulen model (54) is based on the reaction between Si and oxidant at the Si-SiO interface involving both 0 and 0.…”