Comparative study of GaN and AlN nucleation layers and their role in growth of GaN on sapphire by metalorganic chemical vapor deposition
Comparative study of GaN and AlN nucleation layers and their role in growth of GaN on sapphire by metalorganic chemical vapor deposition
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DOI：
10.1063/1.1328091
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发表时间：
2000-11-20
影响因子：
4
通讯作者：
Mahajan, S
中科院分区：
文献类型：
--
作者：
Lorenz, K;Gonsalves, M;Mahajan, S
利用透射电子显微镜和原子力显微镜研究了用金属有机化学气相沉积（MOCVD）法在蓝宝石衬底上生长的低温GaN和AlN成核层（NLs）的微观结构以及高温退火后的微观结构和表面形貌变化。在退火时，两个NL使用不同的路径经历变化，导致岛浸没在连续的GaN和AlN NL中。在退火过程中的NL的微观结构的重排的可能的解释建议为每种情况下。HT-GaN在GaN NLs上的阶梯流动生长直接从现有圆形成核岛的阶梯壁架开始，而GaN岛在波状表面上的成核先于AlN NLs上的阶梯流动生长。由于AlN和GaN之间的表面能差异，AlN纳米线上的平顶岛的早期外观被占的局部生长增强。(C)2000年美国物理学会。【S0003-6951（00）02747-9】。
Microstructures of low-temperature GaN and AlN nucleation layers (NLs) grown on sapphire by metalorganic chemical vapor deposition and changes in these microstructures and surface morphologies upon annealing at high temperature (HT) were investigated by transmission electron microscopy and atomic force microscopy. Upon annealing, both NLs undergo changes using different pathways, resulting in islands submerged in continuous GaN and AlN NLs. Possible explanations for the rearrangement of the microstructure during annealing of the NLs are suggested for each case. The step flow growth of HT-GaN on GaN NLs initiates directly from the step ledges of the existing rounded nucleation islands, while nucleation of GaN islands on the undulated surface precedes the step flow growth on AlN NLs. The earlier appearance of flat-top islands on AlN NLs was accounted for by localized growth enhancement due to the surface energy difference between AlN and GaN. (C) 2000 American Institute of Physics. [S0003-6951(00)02747-9].