Joint Raman spectroscopy and HRXRD investigation of cubic gallium nitride layers grown on 3C‐SiC
Joint Raman spectroscopy and HRXRD investigation of cubic gallium nitride layers grown on 3C‐SiC
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在 3C-SiC 上生长的立方氮化镓层的联合拉曼光谱和 HRXRD 研究
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
A. Zrenner
中科院分区：
文献类型：
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作者：
M. Rüsing;T. Wecker;G. Berth;D. As;A. Zrenner
立方氮化镓（GaN）薄膜采用高分辨X射线衍射（HRXRD）和拉曼光谱进行分析。采用射频等离子体辅助分子束外延技术在3C-SiC（001）衬底上生长了多个立方GaN层。立方GaN的层厚度在75和505 nm之间变化。HRXRD分析揭示了生长层厚度的Ω扫描的半高全宽（FWHM）的减小，这是由缺陷的部分补偿引起的。拉曼表征证实了良好形成的c-GaN层。纵向光学模式的更详细的检查暗示了拉曼模式的FWHM与位错密度的相关性，这表明通过拉曼光谱在微米尺度上确定位错密度的可能性，这是不可能通过HRXRD。此外，该拉曼分析表明，归一化的拉曼光谱提供了确定薄GaN膜的层厚度的替代方式。
Abstractauthoren Cubic gallium nitride (GaN) films are analyzed with high‐resolution X‐ray diffraction (HRXRD) and Raman spectroscopy. Several cubic GaN layers were grown on 3C‐SiC (001) substrate by radio‐frequency plasma‐assisted molecular beam epitaxy. The layer thickness of the cubic GaN was varied between 75 and 505 nm. The HRXRD analysis reveals a reduction of the full‐width at half‐maximum (FWHM) of omega scans for growing layer thicknesses, which is caused by a partial compensation of defects. The Raman characterization confirms well‐formed c‐GaN layers. A more detailed examination of the longitudinal optical mode hints at a correlation of the FWHM of the Raman mode with the dislocation density, which shows the possibility to determine dislocation densities by Raman spectroscopy on a micrometer scale, which is not possible by HRXRD. Furthermore, this Raman analysis shows that normalized Raman spectra present an alternative way to determine layer thicknesses of thin GaN films.