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A higher sensitivity is achieved by making use of a high electron mobility transistor (HEMT) as the piezoresistive device. The temperature dependence on the electromechanical coupling effect of accelerometers is reported. The current in the structure of our study decreases at the rate of 3.15 mA/ ∘ C with the temperature going up at every region, and piezoresistance coefficient decreases because of the shift of energy and expansion of lattice.

The micro-structure of GaAs HEMT build-in cantileversmass was designed and fabricated. GaAs HEMTs were embeded at the root of cantilevers for increasing the sensitivity to external force. In our experiments, it has been proved that the sensitivity of GaAs HEMT is higher than that of silicon by the Mechanical-Electrical coupling characteristics. The magnitude of the external force was then calculated according to the out-put voltage of GaAs HEMT. This research would be good for developing a new sensor technology .

In this paper, it is researched that how I-V characteristics and piezoresistance coefficient of GaAs-based HEMT-embedded accelerometer change when different temperatures are set. It is shown that saturation current of device would go down if the temperature goes up, which is about 3.1467mA/ , based on the research. However, the device can work well at the temperature range of -50 to 50 , which indicates that it can work safely in the larger temperature range. Piezoresistance coefficient is also in down trend with the temperature rising, that it, it has negative temperature coefficient which is about 0.74%/ , and it's sensitivity is higher than Si.