Temperature Characteristic Optimizations of the RTD Sensitivity for the MEMS Sensor Applications

The electron in the RTD has a high mobility with the resonant tunneling effect. We have embedded the RTD in the structure of MEMS sensor using the meso-piezoresistive effect. The sensitivity of sensors is higher one order of magnitude than the accelerometer which used the silicon piezoresistive strip as sensitive unit. In this paper, we optimize the temperature effect of RTD as the sensitive unit of sensors by reducing the size of emitter mesa of RTD structure. In the experiment, the temperature coefficient reduces from 10μA/°C to 5.22μA/°C at the peak, and reduces from 35μA/°C to 13.88μA/°C at the valley. Meanwhile, the temperature effect of bias voltage sensitivity reduces from 6mA/°C to 2mA/°C at the valley. Finally, the reliability and precision of RTD structure used as the sensitive unit of MEMS sensors is improved.