A Novel Method to Size Resistance for Biasing the POSFET Sensors in Common Drain ConfigurationSensors and Microsystems

Piezoelectric oxide semiconductor field effect transistor (i.e. POSFET) sensor is a class of piezoelectric semiconductor devices which has been proposed for tactile sensing. As these sensors have piezoelectric material on top of the NMOS transistor gate, their bias point behaviour became a matter of speculation for a designer. Therefore, while biasing such sensors, one should take into account the technological spread and the combination of capacitances contributed by the piezoelectric material and the MOSFET. In our work, we will highlight the above issues and then propose a novel approach to fix the bias point of the sensor. Our results are based on the measurement and parameter extractions in a real case. This will give reasons behind the variation in bias points which is commonly observed on the sensors in a chip.