ON-MEMS-CHIP Compact Temperature Sensor for Large-Volume, Low-Cost Sensor Calibration

The work introduces a MEMS temperature sensor for use in the same module of other sensors, to provide optimal measurements for their thermal calibration/compensation purposes. The sensor, made of 25-μm-thick, lowly-doped, epitaxial polysilicon, relies on a multi-mode resonator, where the frequency ratio is used to extract relative temperature changes without the need of an external absolute time reference. Measurements across the [5-85]°C range validate the predictions of the frequency behavior, enabling to estimate ±50 mK
rms
resolution at 4-Hz data rate.