Hyperthermal Oxidation of Si(100)2×1 Surfaces: Effect of Growth Temperature

Abstract

Using reactive molecular dynamics simulations based on the ReaxFF potential, we studied the growth mechanism of ultrathin silica (SiO2) layers during hyperthermal oxidation as a function of temperature in the range 100–1300 K. Oxidation of Si(100){2 × 1} surfaces by both atomic and molecular oxygen was investigated for hyperthermal impact energies in the range of 1 to 5 eV. Two different growth mechanisms are found, corresponding to a low temperature oxidation and a high temperature one. The transition temperature between these mechanisms is estimated to be about 700 K. Also, the initial step of the Si oxidation process is analyzed in detail. Where possible, we validated our results with experimental and ab initio data, and good agreement was obtained. This study is important for the fabrication of silica-based devices in the micro- and nanoelectronics industry and, more specifically, for the fabrication of metal–oxide semiconductor devices.

In situ synchrotron radiation photoelectron spectroscopy study of the oxidation of the Ge(100)-2 × 1 surface by supersonic molecular oxygen beams

“…21 Theoretical studies will be required to obtain detailed physical insight into the origin of O 2 adsorption. [48][49][50] …”

Integrated atomistic chemical imaging and reactive force field molecular dynamic simulations on silicon oxidation

“…We do see the presence of some of these suboxides even in the silicon oxide region III, which can be related to possible presence of overcoordinated and under-coordinated Si atoms that were assumed to be found in this region as per simulations. 11 Also, it was reported that the observed silica region can be divided into surface and bulk regions. 36 In the present case, we refer to a surface silica region and a bulk silica region.…”

“…11 Namely, due to the decreasing of interfacial stresses 42 in Region II, the mobility of oxygen atoms in the transition region increases. While the thickness of the transition region (Region II) is somewhat smaller in the simulation results, the ratio between the thicknesses at both investigated temperatures agrees quantitatively with the experimental result, at a ratio of about 1.3.…”

“…9,10 Recently, a reactive molecular dynamic (MD) simulation studied the temperature dependence of hyperthermal oxidation of silicon and the corresponding atomic scale growth mechanisms. 11 However, there are no corresponding experimental reports at the same length scale due to lateral resolution and mass sensitivity requirements. The objective of the present work is to study the effect of processing conditions on the interfacial properties using in depth atomic scale characterization and, namely, atom probe tomography (APT).…”

“…34 ReaxFF accurately describes bond breaking and formation as well as the expansion of the Si crystal during the oxide formation process, in good agreement with both experimental and density functional theory (DFT) results. 11,[35][36][37] In this work, we use the force field parameters developed by Buehler et al 38 The details of the force field parameters used are provided in the supplementary material. 39 Si(100) 11 reconstructed surface is chosen as the initial structure, with dimensions 21.7 Å Â 21.7 Å Â 27.1 Å .…”