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) approximate to 10(13) cm(-2)) grown on conducting 6H-SiC substrates in the temperature range T = 0.3 - 300 K. The electron mobility in AlGaN-GaN heterostructures grown on SIC was higher than in those on sapphire substrates, especially at cryogenic temperatures. The highest measured Hall mobility at room temperature was mu(H) = 2019 cm(2)/V s. At low temperatures, the electron mobility increased approximately five times and saturated below 10 K at mu(H) = 10250 cm(2)/V s. The experimental results are compared with the electron mobility calculations accounting for various electron scattering mechanisms. (C) 1998 American Institute of Physics.