Deposition of silicon carbide using the chemical vapor composites process: Process characterization and comparison with RASSPVDN model predictions

Abstract

In this work, we explore the use of the chemical vapor composites (CVC) process to increase the rates of silicon carbide (SiC) growth on graphite substrates. Large SiC seed particles are used that are deposited by gravity-driven sedimentation. The results show that addition of large (dp = 28 μm) SiC seed particles to a gas phase containing hydrogen and methyltrichlorosilane increases the deposition rate of SiC by amounts substantially higher than that expected from the addition of the particle volume alone. Insight into the mechanism of this deposition rate enhancement is obtained through analysis of SEM photographs of deposits. Growth rates and deposit structures are consistent with the trends predicted by the previously developed random-sphere model of simultaneous particle-vapor deposition (RASSPVDN), which is used here to interpret the data.