Imaging basal plane stacking faults and dislocations in (11-22) GaN using electron channelling contrast imaging
Imaging basal plane stacking faults and dislocations in (11-22) GaN using electron channelling contrast imaging
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DOI：
10.1063/1.5042515
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发表时间：
2018-08-14
影响因子：
3.2
通讯作者：
Trager-Cowan, Carol
中科院分区：
文献类型：
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作者：
Naresh-Kumar, G.;Thomson, David;Trager-Cowan, Carol
利用扫描电子显微镜中基于电子衍射的测量，可以提供有关半导体薄膜中扩展缺陷的非破坏性和定量信息。在这项工作中，我们研究了在通过金属有机气相外延生长的规则排列的GaN微棒阵列模板上过度生长的（11-22）半极性GaN薄膜。我们能够使用电子通道衬度成像 (ECCI) 来优化衍射条件，以对基面堆垛层错 (BSF) 和螺纹位错 (TD) 进行成像和量化。观察到 BSF 和 TD 簇的周期性与底层微棒阵列模板相同。平均 BSF 和 TD 密度估计分别约为 4 x 10(4) cm(-1) 和约 5 x 10(8) cm(-2)。 ECCI 中 BSF 的对比度与平面透射电子显微镜图像中观察到的对比度相似，唯一的区别是前者获取背散射电子，后者收集透射电子。我们目前的工作展示了 ECCI 量化半极性氮化物中扩展缺陷的能力，并且代表着在优化这些材料的生长条件方面向前迈出了真正的一步。 (C) 2018 年作者。
Taking advantage of electron diffraction based measurements, in a scanning electron microscope, can deliver non-destructive and quantitative information on extended defects in semiconductor thin films. In this work, we have studied a (11-22) semi-polar GaN thin film overgrown on regularly arrayed GaN micro-rod array templates grown by metal organic vapour phase epitaxy. We were able to optimise the diffraction conditions to image and quantify basal plane stacking faults (BSFs) and threading dislocations (TDs) using electron channelling contrast imaging (ECCI). Clusters of BSFs and TDs were observed with the same periodicity as the underlying micro-rod array template. The average BSF and TD densities were estimated to be approximate to 4 x 10(4) cm(-1) and approximate to 5 x 10(8) cm(-2), respectively. The contrast seen for BSFs in ECCI is similar to that observed for plan-view transmission electron microscopy images, with the only difference being the former acquiring the backscattered electrons and the latter collecting the transmitted electrons. Our present work shows the capability of ECCI for quantifying extended defects in semi-polar nitrides and represents a real step forward for optimising the growth conditions in these materials. (C) 2018 Author(s).