Growth of silicon carbide multilayers with varying preferred growth orientation

SiC multilayer coatings were deposited via thermal chemical vapor deposition (CVD) using silicon tetrachloride (SiCl4) and various hydrocarbons under identical growth conditions, i.e. at 1100 ℃ and 10 kPa. The coatings consisted of layers whose preferred growth orientation alternated between random and highly <111>-oriented. The randomly oriented layers were prepared with either methane (CH4) or ethylene (C2H4) as carbon precursor, whereas the highly <111>-oriented layers were grown utilizing toluene (C7H8) as carbon precursor. In this work, we demonstrated how to fabricate multilayer coatings with different growth orientations by merely switching between hydrocarbons. Moreover, the success in depositing multilayer coatings on both flat and structured graphite substrates has strengthened the assumption proposed in our previous study that the growth of highly <111>-oriented SiC coatings using C7H8 was primarily driven by chemical surface reaction.