Low-Temperature Preparation of α-SiC Epitaxial Films by Nd:YAG Pulsed-Laser Deposition

摘要

Reduction of the growth temperature of α-SiC epitaxial film is important in the fabrication of SiC-based devices such as the PN junction and FET. We have grown a-SiC films with one-axis orientation and also epitaxial films at a low substrate temperature of 820℃ by Nd:YAG pulsed-laser deposition, although the epitaxy is not complete. Films fabricated on sapphire (0001) substrates show in-plane (a-b plane) orientation in addition to c-axis orientation normal to the substrate plane. Epitaxial growth was confirmed by reflection high-energy electron diffraction (RHEED) and φ-scan X-ray diffraction (XRD) observations. Films on Si (111) substrates show one-axis orientation with (10-13) plane on the substrate surface. However, no in-plane orientation was found by RHEED or φ-scan XRD of the film. Epitaxial growth of α-SiC film on the sapphire substrate is plausibly explained by the good lattice matching that is attained with a relative rotation of the unit hexagon lattices of the film and the substrate (mismatch 4.1%).