GaAs/AlAs/GaAs氧化前后的微结构表征

Microstructure of GaAs/AlAs/GaAs with and without oxidation

研究了GaAs/AlAs/GaAs三层膜氧化前后成分和微结构的变化。对GaAs/AlAs/GaAs利用横向氧化的方式得到了GaAs/Al2 O3/GaAs薄膜 ,利用X射线小角反射和高角衍射技术进行了微结构表征。结果表明 ,氧化前GaAs/AlAs/GaAs结构中 ,AlAs层与表面GaAs之间存在着一层110 的均匀过渡层。AlAs层分成厚度为 4 0 和 10 5 0 的两层 ,而 4 0 厚的AlAs层的平均原子密度比 10 5 0 厚的减小。利用横向氧化的方式使得AlAs完全氧化为Al2 O3,而且与氧化前相比 ,其过渡层的厚度与粗糙度均减小。

The Changes of compositions and microstructures of GaAs/AlAS/GaAs trilayers before and after oxidation were investigated. GaAs/Al 2O 3/GaAs thin film was obtained from GaAs/AlAs/GaAs by lateral oxidation and its microstructures were investigated by use of X-ray small angle reflectivity and high angle diffraction. The results show that before oxidation there exists an even transition layer with the thickness of 110 between the AlAs layer and the upper GaAs layer. The AlAs layer was separated into two layers, one is of 40 thickness and the other 1050. The average atomic density of the thin AlAs layer is less than that of the thick AlAs layer. After lateral oxidation, AlAs was oxidized into Al 2O 3, and the thickness and roughness of the transition layer metioned above decrease.