Wang Yan, Zhang Shu-yi, Fan Li, Shui Xiu-ji, Zhang Zhong-ning, Wasa Kiyotaka
IEEE Trans Ultrason Ferroelectr Freq Control. 2013 Jun;60(6):1213-8. doi: 10.1109/TUFFC.2013.2684.
(1120)-textured ZnO films are deposited on Rsapphire substrate by RF magnetron sputtering and the effects of deposition conditions on ZnO films are investigated. The chemical compositions of the ZnO films are characterized by X-ray photoelectron spectroscopy and the results indicate that the ratio of latticed oxygen to zinc increases with increasing of oxygen concentration in the sputtering gas, which demonstrates the improvement of crystal structures in ZnO films. To investigate the characteristics of surface acoustic waves excited by the (1120)-textured ZnO films, SAW delay lines based on layered structures of (1120) ZnO film/R-sapphire substrate are fabricated, in which Rayleigh and Love modes are excited along the (0001)- and (1100)-directions of the ZnO films, respectively. The phase velocities and electromechanical coupling factors of both wave modes are characterized as functions of the film-thickness-to-wavelength ratio. The acoustic properties of the layered structures are calculated using the transfer matrix method. The experimental and theoretical results are in good agreement with each other.
通过射频磁控溅射在R蓝宝石衬底上沉积（1120）织构的ZnO薄膜，并研究沉积条件对ZnO薄膜的影响。用X射线光电子能谱对ZnO薄膜的化学成分进行了表征，结果表明，随着溅射气体中氧浓度的增加，晶格氧与锌的比例增加，这表明ZnO薄膜的晶体结构得到了改善。为了研究（1120）织构的ZnO薄膜激发的表面声波特性，制备了基于（1120）ZnO薄膜/R蓝宝石衬底层状结构的声表面波延迟线，其中瑞利模和乐甫模分别沿ZnO薄膜的（0001）和（1100）方向激发。两种波模的相速度和机电耦合系数被表征为膜厚与波长比的函数。使用转移矩阵法计算了层状结构的声学特性。实验结果与理论结果吻合良好。
