High quality AlGaN/GaN heterostructures were grown on sapphire substrates by molecular beam epitaxy with NH3 as gas source. Significant improvement in quality was realized by inserting a low-temperature-grown AlN interlayer during the growth of the thick GaN buffer. Electron mobilities of 1500, 10310, and 12,000 cm2/V s at room temperature, 77 and 0.3 K, respective were demonstrated, and were confirmed to be of 2 degree of freedom by strong and well resolved Shubnikov-de Haas oscillations. As evidenced by photoluminescence measurements and atomic force microscopy, native point defect densities and grain boundaries were effectively reduced in the AlGaN/GaN heterostructures with AlN interlayers.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures|
|State||Published - May 2000|
ASJC Scopus subject areas
- Condensed Matter Physics
- Electrical and Electronic Engineering