CRYSTAL GROWTH & DESIGN
Vapor–Liquid–Solid Growth of 3C-SiC on r-SiC Substrates. 2. Growth Kinetics
2008 VOL. 8, NO. 3 1051–1054
Maher Soueidan,*,†,‡ Gabriel Ferro,† Olivier Kim-Hak,† Nada Habka,† Véronique Soulière,† and Bilal Nsouli‡ Laboratoire des Multimateriaux et Interfaces, UMR-CNRS 5615, UniVersité Claude Bernard Lyon 1, 43 Bd du 11 noV. 1918, 69622 Villeurbanne, France, and Lebanese Atomic Energy Commission-CNRS, P.O. Box 11-8281, Riad El Solh 1107 2260 Beirut, Lebanon ReceiVed NoVember 21, 2007
ABSTRACT: The growth kinetics of 3C-SiC heteroepitaxial layers on R-SiC substrates by a vapor–liquid–solid (VLS) mechanism in Ge-Si melts was investigated. Various parameters were studied such as temperature, melt composition, crucible inner diameter, propane flux, and substrate nature (polytype, polarity, and misorientation). It was found that the growth rate increases with increasing temperature, propane flux, Si content of the melt, and misorientation of the substrate. The calculated activation energy (from 4.7 to 6.6 kcal/mol depending on the substrate type) is very small suggesting that the limiting process is the diffusion of the dissolved carbon inside the melt. The carbon solubility inside the melt mainly affects the carbon dissolution kinetics from the gas phase. The results also suggest that surface effects are important through the layer polarity, the roughness and the emerging defect density. Introduction The most common technique for growing SiC epitaxial thin films is chemical vapor deposition (CVD) under a mixture of H2-SiH4-C3H8. This chemical system has been extensively studied, and the growth rate was found to be dependent not only on the temperature or on the gas phase composition (dilution in H2, precursor fluxes, C/Si ratio)1 but also on the kind of substrate used (polarity, misorientation).1 On Si face R-SiC(0001) misoriented substrates and using cold wall reactors, the activation energy (EA) calculated from the temperature dependence of the growth rate varies from 2 to 22 kcal/mol1–4 with average growth rates
