Heterogeneous integration of MEMS sensor array and CMOS readout IC with Through Silicon Via interconnects
Through Silicon Via (TSV) forms electrical feedthrough and makes it possible to vertically stack chips with various functions which including logic, memory, analog and MEMS etc. This paper presents a TSV 3D- heterogeneous integration structure of MEMS sensor array with CMOS readout IC (ROIC) and its fabrication technology. Surface micromaching of sensor array are co-designed with TSV fabrication processes to enable TSVs for electrical signals output from backside in sensor chip, sensor chip and its corresponding ROIC chip are vertically stacked, and chip to chip interconnection is achieved by Cu/Sn-Cu microbump bonding. The stacked structure are then assembled to relized MEMS-CMOS 3D heterogeneous integration. Overall, the present work describes an approach for high density MEMS integration.