On the origin of epitaxial rhombohedral-B4C growth by CVD on 4H-SiC

• Published in: Dalton transactions : an international journal of inorganic chemistry 2024-06, Vol.53 (25), p.10730-10736
• Main Authors: Sharma, Sachin, Souqui, Laurent, Palisaitis, Justinas, Hoang, Duc Quang, Ivanov, Ivan G, Per O Å Persson, Högberg, Hans, Pedersen, Henrik
• Format: Article
• Language: English
• Subjects: Boron carbide; Carbon; Chemical vapor deposition; Electron energy loss spectroscopy; Epitaxial growth; Film growth; Interlayers; Optoelectronic devices; Raman spectroscopy; Silicon carbide; Substrates; Surface roughness; Thin films
• ISSN: 1477-9226; 1477-9234; 1477-9234
• DOI: 10.1039/d4dt01157k

Rhombohedral boron carbide, often referred to as r-B4C, is a potential material for applications in optoelectronic and thermoelectric devices. From fundamental thin film growth and characterization, we investigate the film-substrate interface between the r-B4C films grown on 4H-SiC (0001) (C-face) and 4H-SiC (0001) (Si-face) during chemical vapor deposition (CVD) to find the origin for epitaxial growth solely observed on the C-face. We used high-resolution (scanning) transmission electron microscopy and electron energy loss spectroscopy to show that there is no surface roughness or additional carbon-based interlayer formation for either substrate. Based on Raman spectroscopy analysis, we also argue that carbon accumulation on the surface hinders the growth of continued epitaxial r-B4C in CVD.