Morphological study of InGaN on GaN substrate by supersaturation
Morphological study of InGaN on GaN substrate by supersaturation
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DOI：
10.1016/j.jcrysgro.2018.12.028
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发表时间：
2019-02-15
影响因子：
1.8
通讯作者：
Amano, Hiroshi
中科院分区：
文献类型：
--
作者：
Liu, Zhibin;Nitta, Shugo;Amano, Hiroshi
用原子力显微镜研究了金属有机气相外延(MOVPE)在c面GaN衬底上生长的InGaN薄层的形貌。出现了三种不同的形态：阶梯状表面、大的平坦的二维(2D)岛和小的高三维(3D)点。较低的生长温度和较高的生长速率(即蒸汽过饱和度增加)改变了InGaN的形貌，从阶梯状转变为2D岛，然后是3D点(当超过3D点的临界厚度时)。GaN衬底较大的错切角度通过降低各阶梯表面的过饱和度，使其形貌由2D岛变为阶梯状。当InN摩尔分数相近时，具有阶梯状形貌的InGaN层具有最高的内量子效率。与在GaN/蓝宝石模板上生长的InGaN相比，在GaN衬底上生长的InGaN更容易实现阶梯状形貌。
The morphology of thin InGaN layers grown on c-plane GaN substrates by metalorganic vapor phase epitaxy (MOVPE) has been studied by atomic force microscopy. Three different morphologies appeared, a stepped surface, large flat two-dimensional (2D) islands and small high three-dimensional (3D) dots. Low growth temperature and high growth rate (i.e. increased vapor supersaturation) changed the InGaN morphology from steps to 2D islands and then 3D dots (when exceeding the critical thickness for 3D dots). Larger miscut angle of GaN substrate changed the morphology from 2D islands to step by decreasing the surface supersaturation of individual terraces. InGaN layers with a stepped morphology had the highest internal quantum efficiency at similar InN mole fraction. InGaN grown on GaN substrate more easily achieved a stepped morphology compared to InGaN on GaN/sapphire templates.