Effect of a SiC seed layer grown at different temperatures on SiC film deposition on top of an AlN/Si(110) substrate

We have formed silicon carbide (SiC) seed layers at various substrate temperatures by ultralow-pressure chemical vapor deposition using monomethylsilane (CH3SiH3) on aluminum nitride (AlN) films grown on off-axis Si(110) substrates. After that, we grew SiC films on the seed layers by pulsed laser deposition using a SiC target. We investigated the effects of the seed layers formed at various temperatures on the crystallinity and surface morphology of the SiC films thereon. The SiC films grown on the seed layers tended to have lower surface roughnesses than the film grown directly on the AlN film. The SiC film grown on the seed layer formed at 600 degrees C on the AlN film had the best crystallinity among the films. The formation of the seed layers had an effect on the relaxation of the internal stress in the SiC films. The SiC film can be used to grow epitaxial graphene by high-temperature annealing, and the AlN layer on Si plays a role in insulating graphene devices from the Si substrate. Therefore, the graphene transistors are one of the possible applications for epitaxial graphene grown on SiC/AlN/Si. (C) 2019 The Japan Society of Applied Physics