Design and fabrication of three-axis accelerometer sensor microsystem for wide temperature range applications using semi-custom process

Abstract

This paper describes an integrated CMOS-MEMS inertial sensor microsystem, consisting of a 3-axis accelerometer sensor device and its complementary readout circuit, which is designed to operate over a wide temperature range from -55 o C to 175 o C. The accelerometer device is based on capacitive transduction and is fabricated using PolyMUMPS, which is a commercial process available from MEMSCAP. The fabricated accelerometer device is then post-processed by depositing a layer of amorphous silicon carbide to form a composite sensor structure to improve its performance over an extended wide temperature range. We designed and fabricated a CMOS readout circuit in IBM 0.13µm process that interfaces with the accelerometer device to serve as a capacitance to voltage converter. The accelerometer device is designed to operate over a measurement range of ±20g. The described sensor system allows low power, low cost and mass-producible implementation well suited for a variety of applications with harsh or wide temperature operating conditions.

Performance enhancement for piezoresistive microaccelerometer by geometrical design: a focused review

“…Currently, new materials are developed for piezoresistive accelerometers in a fast pace with the advanced made in material science. Silicon carbide and diamond have been utilized to build sensor main body, leading to elevated strength and environment tolerance (Merdasi et al, 2014;Marsi et al, 2015;Privorotskaya et al, 2010). Graphene, nanowire and carbon nanotube, inhering excellent gauge factor, have been incorporated in piezoresistive elements for various sensors to raise the measurement sensitivity (Han et al, 2014;Yan et al, 2014;Calleja et al, 2012).…”

Differential Wide Temperature Range CMOS Interface Circuit for Capacitive MEMS Pressure Sensors

“…Figure 1a illustrates the schematic diagram of the differential wide temperature CMOS interface circuit for capacitive MEMS pressure sensors. The circuit uses a switched capacitor technique and a similar circuit has been used previously by our group [ 13 ] for MEMS air flow sensors and by Patel et al [ 14 ] towards chemocapacitive sensing of volatile organic compounds. Here, we use a novel differential input circuit that enables working with MEMS sensors that have a wide range of the steady-state capacitance values from 0.5 pF to 10 pF.…”

“…The biasing circuit when implemented with this resistor can achieve considerably high stability over a wide temperature range. A folded-cascode amplifier with a switched-capacitor common-mode feedback (CMFB) circuit is used as the amplifier in Figure 1a [ 13 ]. A constant- g m biasing circuit is used to bias the amplifier to stabilize the amplifier performance (open loop gain and bandwidth) over the wide temperature range.…”