论文标题
N-极性III氮异质结构中的反转结构域抑制极性控制
Polarity control by inversion domain suppression in N-polar III-nitride heterostructures
论文作者
论文摘要
氮极二氮化物异质结构在高频和高功率应用中提供了比金属极线结构的优点。然而，由于无意的极性反转域（IDS），难以实现III-硝化物中的极性控制。在此，我们进行了一项全面的结构研究，对原子细节和热力学分析进行了对轴上的低温和高温ALN层的极性演化，以及4 $^{\ circ} $ carbon-carbon-face 4H-SIC（000 $ \ bar {1} $）由热门金属金属有机化vapor vapors种植。为了实现所需的生长模式和极性，热力学AL过饱和和底物不良方向角度的变化已经开发出极性控制策略。我们证明，当离轴处实现阶梯流生长模式时，对于高温ALN成核层，ID被完全抑制。我们采用这种方法来证明高质量的N极性外延/GAN/ALN异质结构。
Nitrogen-polar III-nitride heterostructures offer advantages over metal-polar structures in high frequency and high power applications. However, polarity control in III-nitrides is difficult to achieve as a result of unintentional polarity inversion domains (IDs). Herein, we present a comprehensive structural investigation with both atomic detail and thermodynamic analysis of the polarity evolution in low- and high-temperature AlN layers on on-axis and 4$^{\circ}$ off-axis Carbon-face 4H-SiC (000$\bar{1}$) grown by hot-wall metal organic chemical vapor deposition. A polarity control strategy has been developed by variation of thermodynamic Al supersaturation and substrate misorientation angle in order to achieve desired growth mode and polarity. We demonstrate that IDs are totally suppressed for high-temperature AlN nucleation layers when step-flow growth mode is achieved at the off-axis. We employ this approach to demonstrate high quality N-polar epitaxial AlGaN/GaN/AlN heterostructures.
