外延膜的高分辨X射线衍射分析  

High-Resolution X-Ray Diffraction Analysis of Epitaxial Films

作　　者：李长记[1] 邹敏杰 张磊[1] 王元明[1] 王甦程 LI Changji;ZOU Minjie;ZHANG Lei;WANG Yuanming;WANG Sucheng(Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China)

机构地区：[1]中国科学院金属研究所沈阳材料科学国家研究中心,沈阳110016 [2]中国科学技术大学材料科学与工程学院,沈阳110016

出　　处：《金属学报》2020年第1期99-111,共13页Acta Metallurgica Sinica

摘　　要：广泛应用于半导体、铁电和光电材料中的外延结构特征以及应变和缺陷会影响外延膜的物理/化学性能。高分辨X射线衍射是对外延结构进行无损准确表征的关键技术。本文从高分辨X射线衍射与外延结构倒易空间的关系出发,重点阐述高分辨X射线衍射与普通X射线衍射的联系与区别,以强调高分辨X射线衍射特征。以铁电外延膜与衬底结构高分辨X射线衍射为例,系统分析它们的高分辨X射线衍射斑特征,包括共格生长、非共格生长、倾斜生长下衍射斑特征,以及外延膜的尺寸、外延膜的倾斜扭转和外延膜的应变对衍射斑的影响等。结合Si1-xGex(x=0.1)等外延膜结构的具体分析阐述如何通过高分辨X射线衍射谱来获取外延膜结构参数,包括外延膜晶格常数、晶格错配度以及厚度和超晶格等信息。本文还系统介绍了高分辨X射线衍射中的倒易平面图的作法,以及相关的理论和实验方法,并据此获得了PbTiO3外延膜的应力状态、畴结构、相变等结构信息。Epitaxy technique has been widely used for semiconductor, ferroelectric and optical materials in the development of electronic and optoelectronic devices. Epitaxial structures with strain and defects may tune the physical properties or affect the performance of devices. High-resolution X-ray diffraction(HRXRD) has significant advantages over traditional XRD with the features of small divergence,monochromatic incident beam and high resolution detection of the diffracted beam. It is a key technique for accurate characterization of epitaxial structures in non-destructive way. In this paper, the techniques of HRXRD for epitaxial film structure characterization are outlined in terms of the relationship between diffraction and reciprocal space, the difference between high-resolution diffraction and powder diffraction such as the optical system and the geometry mode of scanning etc. Based on the corresponding relationship between the epitaxial film and the matrix structure in the reciprocal space, various factors affectingthe shape of the diffraction spots are analyzed, including the state of lattice match in coherence and noncoherence, super lattice and inclined growth. The other effective factors are also demonstrated, such as finite size of film, tilt and strain of epitaxial film etc. Real examples, such as Si1-xGex(x=0.1) etc., are used to explain how to obtain the structure parameters of the epitaxial films by HRXRD spectrum analysis, including lattice constant, lattice mismatch, thickness and superlattice information. To obtain more epitaxy information, reciprocal space map(RSM) analysis can be feasibly used by reconstruction of a series of HRXRD patterns. By combining HRXRD spectrum and RSM, microstructure characterizations of PbTiO3 epitaxy films, such as micro-strain, domain structure, phase transformation can be quantitatively analyzed.

关 键 词：薄膜生长 外延膜 高分辨X射线衍射 倒易空间作图 

分 类 号：TG142[一般工业技术—材料科学与工程]