SrTiO3基片的晶体质量及表面粗糙结构的X射线研究

用X射线双晶衍射摇摆曲线以及双晶X射线形貌对两个SrTiO₃基片的单晶质量进行了对比研究，并用X射线掠入射镜面反射及漫散射研究了它们的表面粗糙结构．结果表明，两个SrTiO₃基片中都存在镶嵌缺陷，其中一个样品的晶体质量相对较高．两个样品的表面粗糙结构相差很大，包括均方根粗糙度σ和横向相关长度ξ．σ分别为（0.5±0.1）和（1.3±0.1）nm，ξ分别为（1200±200）和（300±20）nm．样品的表面粗糙将增加Ｘ射线的漫散射强度而降低镜面反射的强度．晶体质 关键词：

INVESTIGATION OF THE CRYSTALLINE QUALITY AND SURFACE STRUCTURE OF SrTiO3 SUBSTRATE WAFERS BY X-RAY METHODS

The crystalline quality of two SrTiO₃ substrate wafers has been analyzed by X-ray double crystal rocking curve and topography.The surface structures of these two samples are investigated by grazing X-ray specular reflectivity and diffuse scattering.Results show that there are mosaic defects in both samples,but the crystalline quality of one sample is relatively high.There is big difference in the surface structures of these two samples.The root mean roughness σ of one sample is only (0.5±0.1)nm,while the other one is as high as (1.3±0.1)nm.The lateral correlation length of one sample is (1200±200)nm,but another is (300±20)nm.The rough surface will enhance the X-ray diffuse scattering and reduce the specular reflectivity.The substrate wafer with higher crystalline quality has also a relative smooth surface and is suitable for epitaxial growth.