摘要
Sc2 O 3 /AlGaN/GaN metal-oxide-semiconductor (MOS) high electron mobility transistors were fabricated on (11 2- 0) a -plane, Si-doped epitaxial layers grown by metal organic chemical vapor deposition on (1 1- 20) r -plane sapphire substrates. The gate finger direction was varied from parallel to the in-plane c -axis [0001] to the m -axis [1 0 1- 0] direction perpendicular to the observed striations in surface morphology. The [0001] gate devices show lower drain-source current, mobility, and transconductance than their [1 0 1- 0] counterparts, with a systematic dependence on gate finger direction. The symmetrical gate current-voltage characteristics and low gate current (∼3× 10-9 A at ±5 V) confirm the effectiveness of the MOS gate, which is an attractive approach for these structures containing heavily Si-doped AlGaN. © 2009 American Institute of Physics.