GaN薄膜电子声成像和电子背散射衍射研究

Scanning electron acoustic microscopy and electron backscattering diffraction study of GaN/Al_2O_3 hetero-epitaxial layer film

采用扫描电声显微镜(SEAM)和电子背散射衍射(EBSD)对异质外延在Al2O3衬底上GaN界面区域成像测试分析。异质外延失配应力导致在Al2O3和GaN界面附近的微区晶格畸变在SEAM的声成像中可以清楚看到,而且受应力影响集中区域的微区衬度差异明显。利用EBSD色带图及质量参数分析了失配应力变化,晶格应变和弹性形变在200nm内可以得到释放。

The GaN hetero-epitaxial layer on sapphire （Al2O3 ） substrate is studied through scanning e- lectron acoustic microscopy （SEAM） and electron backscattering diffraction （EBSD）. The micro-area lattice distortion resulting from the hetero-epitaxy mismatch strain at the interface of GaN and sapphire is observed clearly,and the contrast of the micro-area in concentrated region affected by strain is different significantly. The color code map and quality parameter of the electron backscattering diffraction （EBSD） are used to analyze the variation of the mismatch strain, and the lattice strain and elastic deformation could be released within 200 nm.