A silicon resonant thermometer for high pressure and high temperature environment

It is a challenge to develop a thermometer for highly precise silicon pressure sensor used under a high temperature environment such as 200°C; because using on-chip diode for temperature compensation is not desirable due to the leakage current. This paper reports a novel silicon resonant thermometer designed to overcome such a problem. The resonant thermometer is composed of a central beam supported by four beams with anchors and its resonant frequency depends only on the temperature and is not affected by pressure. Experimental results show that the frequency of the resonant thermometer has no dependence of pressure up to 3 MPa, and the accuracy of temperature measurement was 0.0019° C.