用卢瑟福背散射/沟道技术及高分辨X射线衍射技术分析不同Al和In含量的AlInGaN薄膜的应变

利用卢瑟福背散射/沟道技术对在蓝宝石衬底上用金属有机化学气相沉积方法生长的有GaN缓冲层(>2μm)的一系列不同Al和In含量的AlInGaN薄膜进行组分及结晶品质的测量；并结合高分辨X射线衍射技术，通过对AlInGaN的对称(0002)面，及非对称(1015)面的θ—2θ扫描及倒空间扫描，可以精确测定AlInGaN外延层的晶格常数及水平和垂直方向的应变.实验结果表明AlInGaN 薄膜中不同含量Al和In对其应变有较大的影响，结合Vegard定理，对这一现象给出了理论的解释. 关键词： AlInGaN 高分辨X射线衍射 卢瑟福背散射/沟道 弹性应变

Strain in AlInGaN thin films caused by different contents of Al and In studied by Rutherford backscattering/channeling and high resolution X-ray diffraction

A series of AlInGaN films with different contents of Al and In were grown by metal-organic chemical vapor deposition on sapphire with GaN (>2μm) intermediate layer. Rutherford backscattering/channeling was used to measure the compositions and the crystal quality of the AlInGaN films. Combining with the high resolution x-ray diffraction, the lattice constants and the strain in perpendicular andthe parallel directions of the AlInGaN epilayer can be determined accurately bytheθ-2θ scan of (0002) and (1015) reflections and the reciprocal-space x-ray mapping. We find that different contents of In and Al can effect the strain in the quaternary AlInGaN films obviously, and with the help of Vegard's law we give an explanation for this phenomenon.