BxGa1-xN (x ∼ 0.02) micro-islands provide novel buffers for growing GaN films and AlGaN/GaN heterostructures on sapphire substrates. These films and heterostructures show low threading dislocation density (TDD), low residual carrier concentration, and high two-dimensional electron gas (2DEG) mobility: Non-doped GaN films had the TDD of 2 × 108 cm-2 and the residual electron concentration of 9.4 × 109 cm-3 at 433 K. AlGaN/GaN heterostructures exhibited 2DEG Hall mobility of 1720 and 13100 cm2 V-1 s-1 at 300 and 77 K, respectively. An almost constant sheet electron density (2.9-4.2 × 1012 cm-2) was obtained in the wide temperature range from 500 to 77 K, indicating the absence of parallel conduction in the GaN buffer layers.
|ジャーナル||Japanese Journal of Applied Physics, Part 2: Letters|
|出版ステータス||Published - 2005 12月 16|
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