【作者】 张忠山； 汤亮；

【Author】 ZHANG Zhong-shan;TANG Liang;Institute of Acoustic, Chinese, Academy of Science;

【机构】 中国科学院声学研究所；

【摘要】 薄膜体声波谐振器是一种采用MEMS技术实现的射频谐振器,制备工艺与IC兼容,不仅器件的体积小而且品质因数高、频率高、矩形度好、插入损耗小,是构建无线通信滤波器的最佳选择。薄膜体声波谐振器的性能主要决定于压电薄膜的性能,压电薄膜性能主要跟晶向择优取向、表面粗糙度、晶粒形貌有关。而薄膜内的残余应力较大会导致支撑薄膜破裂致使器件制备失败。本文首先采用射频磁控反应溅射方法,通过优化衬底温度、射频功率、溅射气压和气体比例制备成功低应力的氮化铝压电薄膜,利用薄膜应力计测量残余应力为50MPa,利用XRD测量的最强衍射峰位于2θ=36°,利用AFM测量表面粗糙度为3.67nm,利用SEM观察晶粒形貌为竖直纤维状;间接证明了薄膜存在压电性能的可能。然后基于以上压电薄膜制备的HBAR器件能够产生谐振,而且谐振频率间隔与理论计算一致,直接证明了薄膜存在压电性能;最后基于以上压电薄膜制备成功薄膜体声波谐振器。更多还原

【Abstract】 The thin film bulk acoustic Resonator is a kind of radio frequency resonator realized by MEMS technology. Its fabrication process is compatible with that of integrated circuit. And it possesses advantages of small size, high frequency, good rectangular, low insertion loss. It is the best option to build a wireless communication filter. The characteristic of thin film bulk acoustic resonator is determined by the characteristic of piezoelectric film. The characteristics of piezoelectric film are mainly related to orientation, surface roughness and grain morphology. And the residual stress in film causes the failure of the device. In this paper, firstly, the radio frequency magnetron reaction sputtering method is adopted to prepare piezoelectric film. And the nitride aluminum piezoelectric film is successfully prepared by optimize radio frequency power, sputtering pressure, and substrate temperature, gas proportion. The residual stress of nitride aluminum piezoelectric film is measured by the film stress meter and 50 MPa. The strongest diffraction peak measured by XRD localized at 2θ=36°. The surface roughness measured by AFM is 3.67 nm. The vertical fibrous grain morphology is observed by SEM. Those indirectly prove the existence of piezoelectric possibility. Then the FBAR based on the above piezoelectric film can produces resonance and the frequency spacer agrees with the theoretical value. This directly proves the existence of piezoelectric possibility. At last, the FBAR based on the above piezoelectric film is successfully prepared.更多还原