Ultrafast sputtered ZnO thin films with high kT for acoustic wave device applications
Ultrafast sputtered ZnO thin films with high kT for acoustic wave device applications
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DOI：
10.1109/ultsym.2010.5935455
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发表时间：
2010-10
期刊：
影响因子：
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通讯作者：
L. Garcia-Gancedo;J. Pedrós;A. Flewitt;W. Milne;G. Ashley;Jack K. Luo;C. Ford
中科院分区：
文献类型：
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作者：
L. Garcia-Gancedo;J. Pedrós;A. Flewitt;W. Milne;G. Ashley;Jack K. Luo;C. Ford
高频声波器件的制造需要开发具有改进的形态和电声性能的压电材料薄膜。特别是，薄膜的晶体取向，表面形貌，薄膜应力和电阻率是压电响应的关键问题。在这里报道的工作中，ZnO薄膜以高速率（>50 nm/min）沉积，使用称为高靶利用率溅射（HiTUS）的新工艺。所沉积的薄膜具有良好的晶体取向性、高电阻率（> 109 Ωm）、表面粗糙度和薄膜应力比标准磁控溅射法低一个数量级。通过共振谱法精确计算了薄膜的机电耦合系数kT，并发现其至少比作者所知的磁控溅射薄膜的kT高6%。膜的低膜应力被认为是获得高kT值的最重要因素之一。
The fabrication of high frequency acoustic wave devices requires the development of thin films of piezoelectric materials with improved morphological and electro-acoustical properties. In particular, the crystalline orientation of the films, surface morphology, film stress and electrical resistivity are key issues for the piezoelectric response. In the work reported here, ZnO thin films were deposited at high rates (>50 nm/min) using a novel process known as the High Target Utilisation Sputtering (HiTUS). The films deposited possess excellent crystallographic orientation, high resistivity (> 109 Ωm), and exhibit surface roughness and film stress one order of magnitude lower than films grown with standard magnetron sputtering. The electromechanical coupling coefficient of the films, kT, was precisely calculated by implementing the resonant spectrum method, and was found to be at least 6% higher than any previously reported kT of magnetron sputtered films to the Authors' knowledge. The low film stress of the film is deemed as one of the most important factors responsible for the high kT value obtained.