Epitaxial Deposition of SiC onto 4H SiC using a Hollow Cathode

摘要

Thin films of SiC were deposited using DC, RF and pulsed sputtering of a hollow cathode. The majority of the films were deposited using RF sputtering at temperatures ranging from 610 to 858°C. Initial films were deposited onto Si substrates in order to determine deposition rates, film uniformity, and film composition. The introduction of a rotating substrate holder greatly improved the film thickness and composition uniformity. The samples were characterized using X-ray diffraction (XRD), Raman spectroscopy, optical absorption, and infrared ellipsometry. The initial films were polycrystalline in nature independent of the substrate used for deposition. The 4H/3C polytype ratio increases strongly for elevated substrate temperatures for the films which were grown homo-epitaxially on 4H SiC. This observation suggests a new avenue for homo-epitaxial growth of SiC onto 4H SiC and rapid hollow cathode sputtering is envisioned for the growth of single crystal films of 4H SiC for future device applications.