Determination of the indium content and layer thicknesses in InGaN/GaN quantum wells by x-ray scattering
Determination of the indium content and layer thicknesses in InGaN/GaN quantum wells by x-ray scattering
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DOI：
10.1063/1.1587251
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发表时间：
2003-07
影响因子：
3.2
通讯作者：
M. E. Vickers;M. Kappers;T. Smeeton;E. Thrush;J. Barnard;C. Humphreys
中科院分区：
文献类型：
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作者：
M. E. Vickers;M. Kappers;T. Smeeton;E. Thrush;J. Barnard;C. Humphreys
我们已经确定了铟含量和层厚度的InGaN外延层和InGaN/GaN量子阱结构的高分辨率X射线衍射（XRD）使用（002）反射。超晶格中的总重复（InGaN阱加上GaN势垒）的厚度容易从ω/2 θ扫描中的卫星峰之间的间距确定。InGaN和GaN层的单独厚度和铟含量的测量不那么直接，因为对于多层结构，峰值位置受铟含量和GaN与InGaN层的厚度比的影响。因此，几个不同的模型可以合理地拟合在有限范围内（（002）两侧约1° Ω/2 θ）收集的数据，仅显示低阶（-3至+3）卫星峰。只要有可能，我们已经收集了广泛的范围内（约4° Ω/2 θ）的数据，并确定了通过检查弱高阶卫星的相对强度的厚度比。
We have determined the indium content and the layer thicknesses in an InGaN epilayer and InGaN/GaN quantum well structures by high-resolution x-ray diffraction (XRD) using the (002) reflection. The thickness of the total repeat (an InGaN well plus a GaN barrier) in the superlattice is easily determined from the spacing between the satellite peaks in an omega/2theta scan. Measurement of the individual thickness of InGaN and GaN layers and the indium content is less straightforward, since for multilayer structures the peak positions are influenced by both the indium content and the thickness ratio of the GaN to the InGaN layer. Thus, several different models may give reasonable fits to data collected over a limited range (about 1° omega/2theta either side of the (002)) showing only lower-order (−3 to +3) satellite peaks. Whenever possible, we have collected data over a wide range (about 4° omega/2theta) and determined the thickness ratio by examination of the relative intensities of weak higher-order satell...