The Effect of Drain/Gate Bias on Electromechanical Coupling Effect in Accelerometer Based on MESFET

The paper reports a GaAs micro accelerometer by making use of the electromechanical coupling effect based on metal-semiconductor field effect transistor (MESFET). MESFET as a sensitive unit is located at high-stress region to detect the nanometers deformation under stress. The electromechanical coupling effect is validated, and at the same time, the piezoresistive effect and sensitivity, including linear, transition and saturation regions are analyzed under different voltage bias using static and dynamic testing methods. The results indicate that the piezoresistive coefficient and sensitivity of microstructure strongly depend on voltage bias. The transition region between the saturated and linear regions shows a greater sensitivity and piezoresistive coefficient. As a result, the GaAs microstructure based on MESFET can obtain higher piezoresistive coefficient and sensitivity by optimizing the combination of gate and drain voltage.