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arXiv · 2410.07684

Polarity Effect on the Heteroepitaxial Growth of BxC on 4H-SiC by CVD

François Cauwet·Yamina Benamra·Laurent Auvray·Jérôme Andrieux·Gabriel Ferro
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Abstract

The chemical vapor deposition (CVD) growth of boron carbide (B x C) layers on 4H-SiC, 4{\textdegree}off substrates was studied. Depending on the polarity of the substrate, different results were obtained. On Si face, the direct CVD growth at 1600{\textdegree}C under a mixture of BCl 3 +C 3 H 8 systematically led to polycrystalline B x C films, whatever the C/B ratio in the gas phase. On the C face, heteroepitaxial growth was obtained for C/B ratios = 12 or higher with a step bunched morphology. If a boridation step (10 min at 1200{\textdegree}C under BCl 3 flow) was used before the CVD growth, then heteroepitaxy was successful on both substrate polarities. To explain these results, a mechanism is proposed which involves the nature of the chemical bonds at the early stage of nucleation. It is suggested that a full B coverage of the SiC surface should favor the nucleation of the B-rich (0001) plane of B x C, promoting thus the heteroepitaxial growth along this direction.

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François Cauwet, Yamina Benamra, Laurent Auvray, Jérôme Andrieux, Gabriel Ferro. 2024-10-10. Polarity Effect on the Heteroepitaxial Growth of BxC on 4H-SiC by CVD. https://doi.org/10.4028/p-ufrj54

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