Above-IC generic poly-SiGe thin film wafer level packaging and MEM device technology: Application to accelerometers

We present an attractive poly-SiGe thin film packaging and MEM (Micro Electro-Mechanical) platform technology for integrating various packaged MEM devices above standard CMOS. The packages, having cavities as large as 1mm 2 , make use of pillars designed to withstand subsequent molding during 1 st level packaging. Covers on top of the release holes avoid deposition inside the cavity during sealing. Hermeticity is proven in vacuum, air and N 2 atmosphere and at different temperatures. Packaged functional accelerometers sealed at a pressure around 1bar, have an equivalent performance in measuring accelerations of about 1g compared to a piezoelectric commercial reference device.