ELECTRON-TRANSPORT IN ALGAN-GAN HETEROSTRUCTURES GROWN ON 6H-SIC SUBSTRATES

We investigated two-dimensional electron transport in doped AlGaN-GaN heterostructures (with the electron sheet concentration n(s) approxima te to 10(13) cm(-2)) grown on conducting 6H-SiC substrates in the temp erature range T = 0.3 - 300 K. The electron mobility in AlGaN-GaN hete rostructures grown on SIC was higher than in those on sapphire substra tes, especially at cryogenic temperatures. The highest measured Hall m obility at room temperature was mu(H) = 2019 cm(2)/V s. At low tempera tures, the electron mobility increased approximately five times and sa turated below 10 K at mu(H) = 10250 cm(2)/V s. The experimental result s are compared with the electron mobility calculations accounting for various electron scattering mechanisms. (C) 1998 American Institute of Physics.