薄膜体声波滤波器的离子束刻蚀修频工艺  

Frequency Trimming Process of Thin Film Bulk Acoustic Wave Filter by Ion Beam Etching

作　　者：时鹏程 张智欣 张倩 冯志博 倪烨 于海洋 Shi Pengcheng;Zhang Zhixin;Zhang Qian;Feng Zhibo;Ni Ye;Yu Haiyang(Beijing Aerospace Micro Electric Technology Co.,Ltd.,Beijing 100854,China)

机构地区：[1]北京航天微电科技有限公司,北京100854

出　　处：《微纳电子技术》2024年第1期168-174,共7页Micronanoelectronic Technology

摘　　要：薄膜体声波滤波器因设计模型与器件性能存在匹配度问题及制造过程中各工序的累计误差导致频率一致性差,严重影响了产品良率,因此实现晶圆级别的频率修整十分必要。介绍了离子束刻蚀工艺的原理、技术特点与优势,研究了刻蚀电压、刻蚀电流、刻蚀距离、Ar气体体积流量及单次刻蚀量对刻蚀效果的影响,表征了离子束刻蚀工艺对AlN钝化层厚度均一性、刻蚀精度及粗糙度的影响。探究了离子束刻蚀工艺在薄膜体声波滤波器频率修整上的应用,表征了离子束刻蚀工艺对钝化层的表面形貌及晶圆应力的影响。研究结果表明,刻蚀电压为1500 V、刻蚀电流为18 mA、刻蚀气体体积流量为4 cm^(3)/min、刻蚀距离为80 mm时,刻蚀精度高,具有一定借鉴意义;通过3轮电性能测试分析和离子束刻蚀工艺,频率标准差仅为1.23 MHz,大幅提升了薄膜体声波滤波器的频率一致性。Due to the matching degree problem between the design model and device performance,the cumulative error of each process in the productive process,the frequency consistency of thin film bulk acoustic wave filters is poor,which seriously affects the product yield,so it is necessary to realize the frequency trimming at the wafer level.The principle,technical characteristics and advantages of ion beam etching process were introduced.The influences of etching voltage,etching current,etching distance,Ar gas volume flow rate and single etching amount on the etching effect were studied.The influences of ion beam etching process on the thickness uniformity,etching accuracy and roughness of the AlN passivation layer were characterized.The application of ion beam etching technology in the frequency trimming of thin film bulk acoustic filters was investigated.The influences of ion beam etching process on the surface morphology of passivation layer and the stress of wafer were characterized.The study results show that when the etching voltage is 1500 V,the etching current is 18 mA,the etching gas volume flow rate is 4 cm^(3)/min and the etching distance is 80 mm,the etching precision is high,which has certain reference significance.Through three rounds of electrical performance test analysis and ion beam etching process,the frequency standard deviation is only 1.23 MHz,which greatly improves the frequency consistency of the thin film bulk acoustic wave filters.

关 键 词：薄膜体声波滤波器 离子束刻蚀 频率修整 刻蚀速率 膜厚修整 

分 类 号：TB383[一般工业技术—材料科学与工程] TN305.7[电子电信—物理电子学]