Exploring SiC CVD growth parameters compatible with remote epitaxy

Remote epitaxy (RE) is a promising technique where monolayers of van der Waals-bonded (i.e., 2D) material act as a release layer for epitaxial film removal and substrate reuse. Epitaxial graphene (EG) grown in situ on SiC(0001) is an ideal RE substrate as it avoids damage or contamination associated with 2D material transfer. However, standard high-temperature, hydrogen-based SiC chemical vapor deposition (CVD) is not compatible with graphene and alternative growth parameters are required for SiC RE. This study investigates reduced-H2 CVD growth of SiC/C/SiC(0001) and the effects on the in situ-grown EG release layer. This study achieved smooth, single-crystalline SiC(0001) epilayers on EG substrates using predominantly Ar carrier gas (2% H2), but no EG was detected at the growth interface after this deposition. Growth modifications, including a pregrowth propane dose, longer precursor ramp steps with high starting C/Si ratios, and reduced SiC growth temperatures, were explored to further mitigate graphene damage. With these changes, isolated patches of 5–10 nm thick graphitic carbon layers remained after SiC RE. Thermodynamic simulations suggest that lower temperatures and increased C/Si ratios will improve C stability. Through this study, optimal SiC RE growth conditions are proposed for a balance of graphene survivability and SiC morphology.