CMUT面阵制备中的硅通孔金属互连工艺设计  

Design of through silicon via metallization interconnection process in preparation of CMUT planar array

作　　者：王月 何常德[1] 张文栋[1] WANG Yue;HE Changde;ZHANG Wendong(MOE Key Laboratory of Instrument Science and Dynamic Testing,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学仪器科学与动态测试教育部重点实验室,山西太原030051

出　　处：《现代电子技术》2021年第3期162-166,共5页Modern Electronics Technique

基　　金：国家重点研发计划:基于MEMS技术的阵列式微型声压传感器研制(2018YFF01010500);国家杰出青年科学基金:微纳米传感器原理与集成(6142500192)。

摘　　要：CMUT面阵上电极引线随着阵列数目的增多越来越难实现,根据这一情况提出使用硅通孔互连的方法将上电极引到器件背面,通过通孔和微凸点实现与PCB板的垂直电连接。根据实际需求,设计一种基于CMUT面阵的无电镀硅通孔金属互连制备方法,采用深硅刻蚀技术得到通孔,使用磁控溅射镀膜机在通孔内壁沉积金属,实现了任意尺寸硅通孔的快速金属互连。通过比较不同尺寸的通孔直径,实验分析确定380μm厚的硅片最优通孔直径为150μm,此孔径通孔垂直度高,通孔间的电阻均相对较小约为0.6~0.9Ω,通孔导通良好。同时,深硅刻蚀后的通孔都存在过刻现象,在过刻25μm以内,金属图形化时应该留有足够安全距离,为CMUT面阵换能器制备提供实践依据。It is more and more difficult to connect the electrode leads on the CMUT(capacitive micromachined ultrasonic transducer)planar array with the increase of the number of arrays.In view of this,a method of through silicon via(TSV)interconnection is proposed to lead the upper electrode to the back side of the device and realize vertical electrical connection to PCB by through vias and micro⁃bumps.Therefore,an electroless TSV metallization interconnection preparation method based on CMUT planar array is designed.The deep silicon etching technology is used to make the through vias,and metal is deposited on the inner wall of TSV by magnetron sputtering coater to realize fast metallization interconnection of any size TSVs.By comparing the TSVs with different diameters,the optimal through via diameter of silicon wafer with the thickness of 380μm is determined to be 150μm by experimental analysis.The through vias of this aperture have high perpendicularity,and the resistance among them is relatively small(0.6~0.9Ω),so they are of good conductivity.Meanwhile,excessive etching usually occurs to the TSVs after deep silicon etching.When the range of excessive etching is within 25μm,enough safety distance should be reserved when the metal is patterned,which provides practical basis for the preparation of CMUT planar array transducer.

关 键 词：CMUT面阵 上电极引线 TSV技术 深硅刻蚀 磁控溅射 金属互连 

分 类 号：TN405.97-34[电子电信—微电子学与固体电子学]