ANALYSIS OF A PRESSURE SENSOR-BASED ON AN ARRAY OF COLLECTOR-ASSISTEDFIELD-EMISSION TRIODES

The purpose of this paper is to analyze the operation of a pressure se nsor based on an array of collector-assisted field-emission triodes (F ETs). The silicon membrane (the anode of the device) put in front of t he array is bent by the external pressure, and thus, the field-emissio n current is modified. An analytical solution has been used to calcula te the deflection of the silicon diaphragm when the pressure is applie d and a numerical model was developed for the single emitter FET. The array emission current is obtained adding the contributions of all the FETs in the array, no interaction between the emitters being consider ed. The device sensitivity and resolution have been computed as functi ons of both the silicon membrane and FET array parameters. Better sens or sensitivity and resolution are obtained for those situations, which assure higher held-emission currents. A simple analytical model was d eveloped for the field-emission pressure sensor, supporting these obse rvations. The obtained modeling results can be further used for sensor design improvement. (C) 1997 American Institute of Physics.