基于Mg_xZn_(1-x)O薄膜固体装配型体声波谐振器

Solidly mounted film bulk acoustic resonator based on Mg_xZn_(1-x)O thin film

本文研制了一种基于磁控溅射掺镁氧化锌(Mg_xZn_(1-x)O)压电薄膜的S波段固体装配型体声波谐振器(SMR-FBAR)。相比传统的氧化锌(ZnO)薄膜,Mg_xZn_(1-x)O具有高纵波声速,高电阻率优点,而且Mg原子以替位或填隙的方式进入晶格,没有改变ZnO的铅锌矿结构。通过优化磁控溅射参数的方法,获得了c轴方向生长良好的Mg_xZn_(1-x)O薄膜,并成功制得了串联谐振频率以及并联谐振频率分别在2.416 GHz和2.456 GHz的谐振器,测得其有效机电耦合系数为4.081%,回波损耗(S11)为-23.89 d B。这种SMR机械强度高、可靠性高、尺寸小,具有可立体集成到CMOS芯片表面的优势。

With a high mechanical strength and a small size, solidly mounted film bulk acoustic resonator （FBAR） is more advantageous for the next generation S band wireless communication in integrated circuit technology. An S-band FBAR consisting of a novel piezoelectric material MgxZn1-xO is presented in this paper. Compared to traditional ZnO, MgxZn1-xO has a higher acoustic velocity and resistance, and the results show that substituting Mg atoms in an interstitial way would not change wurtzite structure of ZnO. By optimizing various growth conditions, a good c-axis oriented MgxZn1-xO film utilizing magnetron sputtering system was obtained, and then FBARs with a series and parallel resonant frequency of 2.416 GHz and 2.456 GHz respectively had been fabricated. The measured effective electromechanical coupling coefficient and return loss are 4.081% and -23.89 dB respectively.