Boron oxide interaction with silicon in silicon molecular beam epitaxy

Abstract

B2O3 decomposition by reaction with Si has been studied in situ by Auger electron spectroscopy in a Si molecular beam epitaxy environment as a function of the silicon flux (0<JSi<14.5 Å/min) and the growth temperature (25 °C<Ts<800 °C). Quantitative analysis of Auger signals indicates that oxygen is associated with both SiO2 and B2O3. Below a critical substrate temperature (Ts<500 °C), no reaction occurs between B2O3 and Si. When the substrate temperature is higher than 500 °C, the atomic fraction of Si and B increases while that for SiO2 and B2O3 decreases. The chemical reaction which causes the signal changes is thermally activated, as shown by the dependence of the oxygen on boron concentration ratio, I[O/B], which drops rapidly according to an Arrhenius relation with an activation energy Ea=4.5±1.0 eV. From the experimental results, we propose a model which involves B2O3 reduction by Si to form the (Si-B) and SiO2 phases. SiO2 is then decomposed by Si bombardment on the surface to produce SiO which subsequently desorbs.

Development of 10B2O3 processing for use as a neutron conversion material

“…Note the absence of the latter after heat treatment. Some indication exists that temperatures >500 o C lead to reaction of the 10 B 2 O 3 with Si, with possible by-products such as SiO 2 , Si-B compounds, and borosilicates [14]. Though we have observed reductions in pillar size at annealing temperatures larger than 600 o C, no appreciable sample shrinkage effect is found at 500 o C, even when held at this temperature for longer than 24 hours.…”

Oxidation‐led decomposition of hexagonal boron nitride coatings on alloy substrates at 900 °C: Chromia‐formers

“…One of properties of h‐BN that has resulted in a proliferation of applications is its high degree of chemical inertness; its oxide, however, is considerably less inert . Thus, as boron trioxide and the substrate were found to react in the boron trioxide coated SS304 experiments, it is thought that this was also the reaction that led to the formation of chromium borate in the h‐BN coated systems.…”

Post-Synthesis Boron Doping of Silicon Quantum Dots via Hydrosilsesquioxane-Capped Thermal Diffusion

“…While TGA data is largely qualitative and must be interpreted with caution, the observed weight losses can be reasonably attributed to boric acid dehydration (Figure S3). 76,77 We also note that, at the sensitivity of TGA, the processing atmosphere has little impact on the nature of the product mixture when the drive-in step is performed at temperatures of 500 °C or higher.…”