ZnO薄膜的同质外延生长及其结构表征

利用等离子体辅助分子束外延的方法在ZnO单晶衬底上制备了ZnO薄膜。利用X射线衍射(XRD)、同步辐射掠入射XRD和φ扫描等实验技术研究了ZnO薄膜的结构。XRD和φ扫描的结果显示同质外延的ZnO薄膜已经达到单晶水平。掠入射XRD结果表明ZnO薄膜内部不同深度处a方向的晶格弛豫是不一致的,从接近衬底界面处到薄膜的中间部分再到薄膜的表面处,a方向的晶格常数分别为0.3249,0.3258和0.3242 nm。计算得到ZnO薄膜的泊松比为0.156,同质外延的ZnO薄膜与衬底在a轴方向的晶格失配度为-0.123%。

Homoepitaxial Growth and Characterization of ZnO Thin Films

The ZnO films were deposited by plasma-assisted molecular beam epitaxy(MBE) on ZnO single crystalline substrates.The influence of the growth conditions on properties of the ZnO films was evaluated.The microstructures of the ZnO films were characterized with X-ray diffraction,and grazing incidence X-ray diffraction(XRD) with synchrotron radiation and phi-scan XRD.The results show that the crystal relaxation is non-uniform along a-axis in the highly crystallized ZnO film.To be specific,the lattice constants in a-axis direction at the three different positions-bottom up from the substrate/ZnO interface via the mid-section to the surface-were found to be 0.3249,0.3258 and 0.3242 nm,respectively.The calculated results show that poison ratio of the ZnO film is 0.156 and the lattice mismatch of a-axis at the interface is-0.123%.