MEMS resonant sensor has features of high precision

quasi digital output and strong anti-interference.High precision pressure sensors and strain sensors most adopt resonant working principle. The compensation of temperature coefficient of frequency（ TCF） is one of the key issues to realize high precision resonant sensors.Compensation of silicon temperature coefficient of frequency with degenerate doping has been studied by experiments. It is shown by experiments that temperature coefficient of resonant frequency in 〈110 〉orientation decreased to- 11. 68 × 10- 6/ K by 7 × 1019/ cm3P+doping; resonant frequency in〈100〉orientation is quadratic function of temperature after 6 × 1019/ cm3N+doping

temperature coefficient of resonant frequency crosses zero point at about 80 ℃. It has been shown for the first time that the resonant frequency temperature drift is only1. 13 × 10- 7when the ambient temperature changes from 30 ℃ to 40 ℃ with low power consumption heating control combined with N type degenerate doping. Resonant sensors with ultra high temperature stability can be developed with the technique.