Quantitative Analysis for CH 3 Radicals in Low-Temperature Growth of 3C-SiC on Si(001) Clean Surface

Abstract
Using cracked propane (C3H8), carbonization of a Si(001) clean surface with a (2×1) structure can be realized reproducibly at as low as 750°C in gas source molecular beam epitaxy. The carbonized layer indicates single-crystalline 3C-SiC, and surface morphology is very smooth. Methyl (CH3) radicals in a cracked-C3H8 molecular beam can be detected with a mass spectrometer utilizing a threshold ionization technique. The number of CH3 radicals is estimated, and it can reach up to 3.0×1011 cm-3 with a C3H8 flow rate of 0.8 sccm and a cracker temperature of 1200°C. Based on quantitative analysis, the condensation coefficient of CH3 radicals in carbonization is discussed.