纳米异质外延层与衬底的晶体取向匹配的电子背散射衍射分析

Electron backscatter diffraction analysis on crystal orientation match of nano-scaled heteroepitaxial layers with the substrates

本文采用电子背散射衍射(EBSD),测量纳米异质外延层的织构,及外延层与衬底的晶体取向匹配。测试的材料包括作为YBCO超导膜的过渡层、生长在强立方织构Ni-5at.%W(Ni-W)衬底上的La2Zr2O7(LZO)外延层,及LED器件中生长在蓝宝石衬底上的GaN过渡层和外延层。EBSD测量出LZO外延层具有旋转立方织构,显示出LZO与Ni-W衬底的面内取向(转动45°)及面外取向(沿[001]方向)的匹配关系。EBSD测量出GaN过渡层与蓝宝石衬底的面内取向(转动30°)的匹配关系,显示出由GaN过渡层的晶格畸变而引入的平行于外延生长方向的弹性应变梯度(约500 nm)。

The electron backscatter diffraction（EBSD） was used to measure textures and correlations of crystal orientations between nano-scaled heteroepilayers and substrates.The measured materials include La2Zr2O7（LZO） buffer layer as YBCO superconductor films deposited on a Ni-5at.% W（Ni-W） substrate with a strong cube texture,as well as GaN buffer layers and GaN epilayer grown on a sapphire substrate in LED devices.The EBSD was used to measure a rotated cube texture of the LZO epilayer and to reveal its relative orientation in-plane（45° rotation） and out of plane direction（towards[001]direction） with its Ni-W substrate.The relative orientation of GaN buffer in-plane（30° rotation） with its sapphire substrate was measured to reveal an elastic strain gradient parallel to epitaxial growth direction（（500 nm） resulted from the lattice distortation in GaN buffer layer.