Aluminum nitride-silicon carbide solid solutions grown by plasma-assisted, gas-source molecular beam epitaxy

Solid solutions of aluminum nitride (AlN) and silicon carbide (SiC) have been grown at 900-1300°C on vicinal α(6H)-SiC(0001) substrates by plasma-assisted, gas-source molecular beam epitaxy. Under specific processing conditions, films of (AlN)_x(SiC)_1-x with 0.2 ≤ x ≤ 0.8, as determined by Auger electron spectrometry (AES), were deposited. Reflection high-energy electron diffraction (RHEED) was used to determine the crystalline quality, surface character, and epilayer polytype. Analysis of the resulting surfaces was also performed by scanning electron microscopy (SEM). High-resolution transmission electron microscopy (HRTEM) revealed that monocrystalline films with x ≥ 0.25 had the wurtzite (2H) crystal structure; however, films with x < 0.25 had the zincblende (3C) crystal structure.