Suspended Piezoresistive Silicon Nanogauges Bridge For Mems Transduction: Spurious Signal Rejection Capability

This paper reports a resistor bridge made of two suspended piezoresistive silicon nanowires and shows that such a transduction system is particularly suitable for sensing mechanical motion in MEMS. Thanks to their small cross section, silicon nanogauges are extremely sensitive to stress caused by MEMS motion. Because of its sensitivity to some spurious signals, like temperature variations or substrate internal stresses, a nanogauge resistor alone does not provide a signal that meets usual specification requirements for static sensors like accelerometer, magnetometer or pressure sensor. Here, we show, for the first time, the capability of suspended nanogauges bridges to reject temperature signal changes by a factor larger than 1000, over a wide temperature range [-40 degrees C, 150 degrees C], when compared to a nanogauge alone.