Hydride CVD Hetero-epitaxy of B12P2 on 4H-SiC

作者：Frye C D; Saw C K; Padavala Balabalaji; Nikolic R J; Edgar J H

来源：Journal of Crystal Growth, 2017, 459: 112-117.

DOI：10.1016/j.jcrysgro.2016.11.101

• Chemical vapor deposition processes
• Hydride vapor phase epitaxy
• Borides
• Semiconducting boride compounds

Icosahedral boron phosphide (B12P2) is a wide bandgap semiconductor (3.35 eV) that has been reported to "self-heal" from high-energy electron bombardment, making it attractive for potential use in radioisotope batteries, radiation detection, or in electronics in high radiation environments. This study focused on improving B12P2 hetero-epitaxial films by growing on 4H-SiC substrates over the temperature range of 1250-1450 degrees C using B2H6 and PH3 precursors in a H-2 carrier gas. XRD scans and Laue transmission photographs revealed that the epitaxial relationship was (0001) < 11 (2) over bar0 >(B12P2)parallel to(0001) < 11 (2) over bar0 >(4H-SiC). The film morphology and crystallinity were investigated as a function of growth temperature and growth time. At 1250 degrees C, films tended to form rough, polycrystalline layers, but at 1300 and 1350 degrees C, films were continuous and comparatively smooth (R-RMS <= 7 nm). At 1400 or 1450 degrees C, the films grew in islands that coalesced as the films became thicker. Using XRD rocking curves to evaluate the crystal quality, 1300 degrees C was the optimum growth temperature tested. At 1300 degrees C, the rocking curve FWHM decreased with increasing film thickness from 1494 arcsec for a 1.1 mu m thick film to 954 arcsec for a 2.7 mu m thick film, suggesting a reduction in defects with thickness.

• 出版日期2017-2-1