Growth of high-quality AlGaN/GaN heterostructures on sapphire by ammonia gas-source molecular beam epitaxy is reported. Incorporation of a thin AlN layer grown at low temperature within the GaN buffer is shown to result in enhanced electrical and structural characteristics for subsequently grown heterostructures. AlGaN/GaN structures exhibiting reduced background doping and enhanced Hall mobilities (2100, 10310 and 12200 cm2/Vs with carrier sheet densities of 6.1 × 1012 cm-2, 6.0 × 1012 cm-2, and 5.8 × 1012 cm-2 at 300 K, 77 K, and 0.3 K, respectively) correlate with dislocation filtering in the thin AlN layer. Magnetotransport measurements at 0.3 K reveal well-resolved Shubnikov-de Haas oscillations starting at 3 T.
|Original language||English (US)|
|Journal||MRS Internet Journal of Nitride Semiconductor Research|
|Issue number||SUPPL. 1|
|State||Published - 2000|
ASJC Scopus subject areas
- Materials Science(all)