A highly sensitive MOSFET gas sensor based on charge plasma and catalytic metal gate

This manuscript presents, for the first time, a catalytic metal gate-based charge plasma (CP) MOSFET with improved sensitivity for gas detection applications. In this design, CP refers to the source and drain boundaries being marked by depositing metal electrodes with appropriate work function over the intrinsic silicon film. To sense hydrogen and oxygen gases, palladium (Pd) and silver (Ag) metals are respectively deposited as gate electrodes on P-CP-MOSFET and N-CP-MOSFET. Further, sensitivity of CP-MOSFET sensor is determined as if gas molecules are present and the results have been evaluated in comparison with the sensitivity of conventional gas sensor using bulk MOSFET in ATLAS TCAD device simulator. The effect of process variations on sensitivity has also been compared for both devices. The proposed device resolves fabrication complexity issues and offers better sensitivity.