Oxidation of silicon: Further tests for the interfacial silicon emission model

Abstract

The classical description of Si oxidation given by Deal and Grove has well-known limitations for thin oxides ͑below 200 Å͒. Among the large number of alternative models published so far, the interfacial emission model has shown the greatest ability to fit the experimental oxidation curves. It relies on the assumption that during oxidation Si interstitials are emitted to the oxide to release strain and that the accumulation of these interstitials near the interface reduces the reaction rate there. The resulting set of differential equations makes it possible to model diverse oxidation experiments. In this paper, we have compared its predictions with two sets of experiments: ͑1͒ the pressure dependence for subatmospheric oxygen pressure and ͑2͒ the enhancement of the oxidation rate after annealing in inert atmosphere. The result is not satisfactory and raises serious doubts about the model's correctness.

Oxygen partial pressure dependence of the SiC oxidation process studied by in-situ spectroscopic ellipsometry

“…However, to confirm the argument derived from the experimental results in this study, it is necessary to perform numerical calculations of the oxide growth rates within the framework of the Si-C emission model, taking into account the contribution from oxidation on the surface. In the case of Si oxidation, the interfacial Si emission model 21 cannot reproduce the growth rate in the thin oxide region at sub-atmospheric pressures, as pointed out by Farjas and Roura, 20 where the introduction of the contribution from the surface oxide growth may dissolve the disagreement between the calculated and observed oxide growth rates.…”

“…12,20 However, in investigations on Si oxidation mechanisms, the cause of the rapid deceleration has not yet been clarified. That is, the DealGrove model cannot fully account for the initial rapid deceleration.…”

“…In the case of Si oxidation, a rapid deceleration stage has also been observed just after oxidation starts, and the thickness corresponding to X c is also almost independent of the oxygen partial pressure, though the growth rates at X c depend on the oxygen partial pressure. 12,20 Therefore, it can be stated that X c is determined only by the thickness of the oxide layer for both the Si and SiC oxidation cases. It is to be noted that the value of X c is very close to the thickness at which the interface structures become constant as revealed above.…”

“…However, the model also cannot reproduce the remarkable rapid deceleration at sub-atmospheric oxygen pressures, as pointed out by Farjas and Roura. 20 For SiC oxidation, Yamamoto et al tried to reproduce the observed data using Massoud's empirical equation. [8][9][10] Here, we discuss the reasons why two deceleration stages exist in the thickness dependence of oxide growth rate, based on the Si-C emission model.…”

Si and C emission into the oxide layer during the oxidation of silicon carbide and its influence on the oxidation rate

“…In previous work involving Si oxidation, this deceleration phenomenon has been confirmed by observing the increase in the re-oxidation rate after Ar annealing, which was attributed to the diffusion of Si interstitials from the interface. 24 In this letter, we describe the behavior of Si and C atoms during the oxidation of SiC by depth-profiling oxidized HfO 2 /SiC structures using time-of-flight secondary ion mass spectroscopy (TOF-SIMS) and angle-resolved X-ray photoemission spectroscopy (AR-XPS). We attempted to observe the transient period from the initial step in which oxide growth on the oxide surface is predominant (i.e.…”