Structural and luminescence imaging and characterisation of semiconductors in the scanning electron microscope
Structural and luminescence imaging and characterisation of semiconductors in the scanning electron microscope
复制标题
扫描电子显微镜中半导体的结构和发光成像与表征
DOI：
10.1088/1361-6641/ab75a5
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发表时间：
2020-05-01
影响因子：
1.9
通讯作者：
Winkelmann, A.
中科院分区：
文献类型：
--
作者：
Trager-Cowan, C.;Alasmari, A.;Winkelmann, A.
扫描电子显微镜技术，如电子背散射衍射(EBSD)、电子沟道对比成像(ECCI)和阴极发光(CL)高光谱成像，以几十纳米的空间分辨率快速和非破坏性地提供关于材料结构和发光特性的补充信息。EBSD提供晶体取向、晶相和应变分析，而ECCI用于确定给定样品大范围内扩展缺陷的平面分布。化学发光揭示了晶体结构、组成和应变对本征发光的影响和/或揭示了与缺陷有关的发光。在化学发光图像中也观察到暗特征，其中缺陷处的载流子复合是非辐射的。这些技术的结合是澄清结晶学和扩展缺陷对材料发光性能的作用的有效方法。在这里，我们描述了EBSD，ECCI和CL技术，并说明了它们在研究紫外发射氮化物半导体结构和发光性质方面的应用。讨论了我们对GaN、AlN和AlGaN薄膜中缺陷类型、密度和分布的研究，并讨论了GaN纳米线的极性确定。
The scanning electron microscopy techniques of electron backscatter diffraction (EBSD), electron channelling contrast imaging (ECCI) and cathodoluminescence (CL) hyperspectral imaging provide complementary information on the structural and luminescence properties of materials rapidly and non-destructively, with a spatial resolution of tens of nanometres. EBSD provides crystal orientation, crystal phase and strain analysis, whilst ECCI is used to determine the planar distribution of extended defects over a large area of a given sample. CL reveals the influence of crystal structure, composition and strain on intrinsic luminescence and/or reveals defect-related luminescence. Dark features are also observed in CL images where carrier recombination at defects is non-radiative. The combination of these techniques is a powerful approach to clarifying the role of crystallography and extended defects on a material's light emission properties. Here we describe the EBSD, ECCI and CL techniques and illustrate their use for investigating the structural and light emitting properties of UV-emitting nitride semiconductor structures. We discuss our investigations of the type, density and distribution of defects in GaN, AlN and AlGaN thin films and also discuss the determination of the polarity of GaN nanowires.