On the use of methane as a carbon precursor in Chemical Vapor Deposition of silicon carbide

• It is possible to use methane for CVD of high quality epitaxial layers of SiC.
• Narrower C/Si ratio for CVD using methane compared to CVD using ethylene.
• Methane has much higher sticking coefficient than what is believed today.

It is generally considered that methane is not a suitable carbon precursor for growth of silicon carbide (SiC) epitaxial layers by Chemical Vapor Deposition (CVD) since its use renders epitaxial layers with very high surface roughness. In this work we demonstrate that in fact SiC epitaxial layers with high-quality morphology can be grown using methane. It is shown that a key factor in obtaining high-quality material is tuning the C/Si ratio of the process gas mixture to a region where the growth is limited neither by carbon nor by silicon supplies. From the growth characteristics presented here, we argue that the reactivity of methane with the SiC surface is much higher than generally assumed in SiC CVD modeling today.