Ding Rui, Xuan Weipeng, Dong Shurong, Zhang Biao, Gao Feng, Liu Gang, Zhang Zichao, Jin Hao, Luo Jikui
Key Lab of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310063, China.
MOE Frontier Science Center for Brain Science & Brain-Machine Integration, Zhejiang University, Hangzhou 310063, China.
Nanomaterials (Basel). 2022 Sep 5;12(17):3082. doi: 10.3390/nano12173082.
To meet the stringent requirements of 5G communication, we proposed a high-performance bulk acoustic wave (BAW) filter based on single crystal AlN piezoelectric films on a SiC substrate. The fabrication of the BAW filter is compatible with the GaN high electron mobility transistor (HEMT) process, enabling the implementation of the integration of the BAW device and high-performance monolithic microwave integrated circuit (MMIC). The single crystal AlN piezoelectric film with 650-nm thickness was epitaxially grown on the SiC substrate by Metal Organic Chemical Vapor Deposition (MOCVD). After wafer bonding and substrate removal, the single crystal AlN film with electrode layers was transferred to another SiC wafer to form an air gap type BAW. Testing results showed that the fabricated resonators have a maximum Q-factor up to 837 at 3.3 GHz resonant frequency and electromechanical coupling coefficient up to 7.2%. Ladder-type filters were developed to verify the capabilities of the BAW and process, which has a center frequency of 3.38 GHz with 160 MHz 3 dB bandwidth. The filter achieved a minimum 1.5 dB insertion loss and more than 31 dB out-of-band rejection. The high performance of the filters is attributed to the high crystallinity and low defects of epitaxial single crystal AlN films.
为满足5G通信的严格要求，我们提出了一种基于碳化硅衬底上的单晶AlN压电薄膜的高性能体声波（BAW）滤波器。BAW滤波器的制造与氮化镓高电子迁移率晶体管（HEMT）工艺兼容，能够实现BAW器件与高性能单片微波集成电路（MMIC）的集成。通过金属有机化学气相沉积（MOCVD）在碳化硅衬底上外延生长了厚度为650nm的单晶AlN压电薄膜。经过晶圆键合和衬底去除后，将带有电极层的单晶AlN薄膜转移到另一个碳化硅晶圆上，形成气隙型BAW。测试结果表明，所制备的谐振器在3.3GHz谐振频率下的最大品质因数高达837，机电耦合系数高达7.2%。开发了梯形滤波器以验证BAW及其工艺的性能，该滤波器的中心频率为3.38GHz，3dB带宽为160MHz。该滤波器实现了最低1.5dB的插入损耗和超过31dB的带外抑制。滤波器的高性能归因于外延单晶AlN薄膜的高结晶度和低缺陷。
