Controlled CVD Growth of Highly ⟨111⟩-Oriented 3C-SiC

Abstract

Highly ⟨111⟩-oriented 3C-SiC coatings with a distinct surface morphology consisting of hexagonally shaped pyramidal crystals were prepared by chemical vapor deposition (CVD) using silicon tetrachloride (SiCl 4 ) and toluene (C 7 H 8 ) at T ≤ 1250 °C and p tot = 10 kPa. In contrast, similar deposition conditions, with methane (CH 4 ) as the carbon precursor, resulted in randomly oriented 3C-SiC coatings with a cauliflower-like surface of SiC crystallites. No excess carbon was detected in the highly ⟨111⟩-oriented 3C-SiC samples despite the use of aromatic hydrocarbons. The difference in the preferred growth orientation of the 3C-SiC coatings deposited by using C 7 H 8 and CH 4 as the carbon precursors was explained via quantum chemical calculations of binding energies on various crystal planes. The adsorption energy of C 6 H 6 on the SiC (111) plane was 6 times higher than that on the (110) plane. On the other hand, CH 3 exhibited equally strong adsorption on both planes. This suggested that the highly ⟨111⟩-oriented 3C-SiC growth with C 7 H 8 as the carbon precursor, where both C 6 H 6 and CH 3 were considered the main active carbon-containing film forming species, was due to the highly preferred adsorption on the (111) plane, while the lower surface energy of the (110) plane controlled the growth orientation in the CH 4 process, in which only CH 3 contributed to the film deposition.

Nanostructured 3C-SiC on Si by a network of (111) platelets: a fully textured film generated by intrinsic growth anisotropy

“…Indeed, the kinetic origin of such behaviour is suggested by the fact that polycrystalline films deposited by CVD at 1250 °C, with silicon-tetrachloride and toluene precursors, result in highly (111)-oriented crystallites of pyramidal shape with hexagonal basis (by twinning), whereas using methane in place of toluene gives rise to randomly oriented coatings with cauliflower-like crystallites. 14 As the origin of such anisotropy stems from kinetics, rather than thermodynamics, this could suggest that, in our case, further decreasing the {111} incorporation kinetics with low temperatures and carbon saturation, closed pyramidal grains with slanted {111} facets should be formed on the (kinetically) rough (001) and (111) wafer orientations. In our opinion, the presence of many SFs and the ensuing additional growth anisotropy could be the Please do not adjust margins Please do not adjust margins reason for the occurrence of platelets and their lateral extension to the µm size, as we will argue with experimental results and structural interpretations in this paper.…”

Growth of silicon carbide multilayers with varying preferred growth orientation

“…The highly 〈111〉-oriented SiC growth seen in the sample prepared with C 7 H 8 can be attributed to the presence of an aromatic hydrocarbon as C precursor. In our previous study [29], we have shown computationally that in the SiCl 4 + C 7 H 8 process, the primary two carbon-containing active film forming species, C 6 H 6 and CH 3 , adsorbed differently on 3C-SiC (111) and (110) planes. CH 3 adsorbed strongly on both planes, whereas C 6 H 6 chemisorbed on the (111) plane, but only physiosorbed on the (110) plane.…”

“…In our previous work [29], we showed that a highly 〈111〉-oriented 3C-SiC coating can be obtained from a CVD process using silicon tetrachloride (SiCl 4 ) and toluene (C 7 H 8 ) as precursors. We have demonstrated simulations indicating that the preferred orientation arises from the surface chemistry of C 7 H 8 precursor.…”

Silicon Carbide Thin Film Technologies: Recent Advances in Processing, Properties, and Applications - Part I Thermal and Plasma CVD

“…35 ✓SiC multilayered coatings with varying preferred growth orientations as hard coatings for biosensors and biological devices. 53,54 • Ultrafast Data Transmission and Processing:…”