Design and Simulation of Double gate Junctionless Field Effect Transistor for Ammonia Gas Sensing

In this work 2-D Junctionless symmetric double gate field effect transistor(DGJL FET) using catalytic metals as gate electrode is designed for ammonia (NH3) gas detection. Two different catalytic metals Cobalt and Molybdenum are used as gate contact because of their selectivity towards NH3 . When the gas molecules of NH3 are adsorbed over the surface of the catalytic metal gate, it causes considerable variation in electrical characteristics of Double gate Junctionless FET.The proposed device has been simulated using 2-D Sentaurus TCAD device Simulation tool. Simulation results of DGJL FET shows that drain current sensitivity(ON & OFF current), threshold voltage and IDON/IDOFF change significantly as the work function of Cobalt and Molybdenum gate changes from 0meV(without gas molecule) to 50meV and upto 200meV. Thus changes in these electrical characteristics have been used to investigate the response of DGJL FET as NH3 gas sensor.