Controlled n-type doping of AlN:Si films grown on 6H-SiC(0001) by plasma-assisted molecular beam epitaxy

摘要

We study the properties of Si-doped A1N films grown on 6H-SiC(0001) by plasma-assisted molecular beam epitaxy. Whereas nominally undoped A1N films are invariably insulating in nature, Si-doped films are found to be semiconducting with an electron concentration up to 7.4 x 10~(17) cm~(-3), and a resistivity approaching 1 Ω cm at room temperature. Even heavy Si-doping (1 x 10~(20) cm~(-3)) does not degrade the structural properties of the A1N films. The morphology of these films is characterized by Si-induced step-bunching, but remains smooth with a rms roughness of about 1 nm.