Threading dislocation behavior in AlN nucleation layers for GaN growth on 4H-SiC
Threading dislocation behavior in AlN nucleation layers for GaN growth on 4H-SiC
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4H-SiC 上 GaN 生长的 AlN 成核层中的螺纹位错行为
DOI：
10.1063/1.2754638
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发表时间：
2007
影响因子：
4
通讯作者：
J. Powell
中科院分区：
文献类型：
--
作者：
Y. Picard;M. Twigg;M. Mastro;C. Eddy;R. Henry;R. Holm;P. Neudeck;A. J. Trunek;J. Powell
用透射电子显微镜（TEM）研究了在4 H-SiC轴向台面上用金属有机物化学气相沉积（MOCVD）方法生长的薄（<200 nm）AlN成核层（NL）中的位错。AlN NL通过两种确定的机制来控制上覆的102 μ mGaN层中的穿透位错：穿透半环的形成和V形凹坑处的位错弯曲。AlN薄膜中的穿透位错可以直接追溯到衬底/薄膜界面处的双层4 H-SiC台阶。这些观察结果揭示了几种方法，以扩大在4 H-SiC上生长的GaN薄膜中的缺陷减少。
Threading dislocations in thin (<200nm) AlN nucleation layers (NLs) grown by metal-organic chemical vapor deposition on top of 4H-SiC on-axis mesas with atomic-scale steps were analyzed by transmission electron microscopy. The AlN NL controlled threading dislocations in an overlying ∼2μm GaN layer through two identified mechanisms: threading half-loop formation and dislocation bending at V-shaped pits. Threading dislocations in the AlN film could be traced directly to bilayer 4H-SiC steps at the substrate/film interface. These observations reveal several approaches to extended defect reduction in GaN films grown on 4H-SiC.