A Highly Symmetrical Capacitive Accelerometer by Silicon Four-Layer Bonding
一种硅四层键合的高对称电容式加速度传感器

This paper presents a highly symmetrical capacitive accelerometer fabricated by four silicon wafers bonded together.The cantilever-mass structure is fabricated by bonding two wafers together by silicon fusion,and the two static electrodes are bonded later by low-temperature glass melting.Through the silicon bonding,we achieve a wafer-level vacuum package,and the wire-bonding PAD is made after the fabrication is complete.The dimensions of the chip are 6.8mm×5.6mm×1.68mm,and those of the mass are 3.2mm×3.2mm×0.84mm.The test results of the sensor show that the sensitivity is about 6pF/g,the Q value is 35,the resonant frequency is 489Hz,and the leakage is less than 0.1e-9cm3/s.