氮化铝多层膜制备及其声表面波器件性能表征

西安科技大学 理学院,陕西 西安 710054

氮化铝多层膜; 微观结构; 声表面波器件; 温度稳定性

Characterization of the AlN multilayer films and their application on surface acoustic wave devices
PANG Hua-Feng

(College of Sciences,Xi'an University of Science and Technology,Xi'an 710054,China)

AlN multilayered films; microstructure; surface acoustic wave devices; temperature stability

DOI: 10.13800/j.cnki.xakjdxxb.2016.0623

备注

采用直流磁控溅射方法,在硅衬底与超纳米晶金刚石衬底上沉积生长了氮化铝(0002)择优取向薄膜,研究了不同衬底对氮化铝薄膜应力的影响,并以此氮化铝多层膜为基础通过光刻加工得到声表面波器件,进而对其声学性能进行了分析。结果 表明,在硅基底上沉积的氮化铝薄膜存在压应力,而在超纳米晶金刚石薄膜上生长的氮化铝薄膜表现出拉应力,这可能是因为界面应力平衡诱导产生的结果。氮化铝多层膜声表面波器件表现出较强的共振信号,硅衬底上声表面波器件的频率温度系数为-38 ppm/℃,超纳米晶金刚石夹层的引入可有效改善器件的温度稳定性使频率温度系数减小到-28 ppm/℃,同时也显著地提高了机电耦合系数约达0.3%.

AlN multilayered films with and without an ultra-nanocrystalline diamond(UNCD)interlayer were deposited using DC reactive magnetron sputtering system.These films were characterized and applied for the fabrication of surface acoustic wave(SAW)devices.The results show that(0002)oriented AlN multilayered films are grown well on the Si and UNCD substrates.The compress stress of the AlN film exists on Si substrate; on the contrast extensile stress appears in the AlN film on the strained UNCD substrate due to the stress counterbalance at the interface.The obtained AlN multilayered SAW devices show a strong resonant signal with large side-lobe suppression.Temperature coefficient of frequency is -38 ppm/℃.However,the introduction of the UNCD interlayer can effectively improve the temperature stability of the SAW devices for -28 ppm/℃.The electromechanical coefficient is also increased up to 0.3%.