Application of a Charge Plasma Tunnel FET with SiGe Pocket as an Effective Hydrogen Gas Sensor

Abstract

In this article, we have investigated the potential applications of a charge plasma TFET with a source pocket (SP-CPTFET) as a hydrogen gas sensor. The Si0.6Ge0.4 source pocket and HfO2 gate dielectric together greatly enhance the drain current. The presence of an intrinsic silicon body in the channel and drain controls the leakage current. Palladium (Pd) is considered the top and bottom gate catalyst for hydrogen (H2) gas sensing. The flat band voltage and CV properties of the sensor change as a result of the adsorption of H-atoms at the Pd-HfO2 and Pd surfaces. As a result, the gate work-function () modulates, affecting the drain current. The electrical analysis of the sensor is carried out in terms of transfer characteristics, band energy, current ratio, interband tunneling rate, and electric field. Additionally, the suggested sensor’s drain current sensitivity and current ratio sensitivity are estimated for various H2 pressure concentrations. The scope of the investigation has been expanded to include the effect of variation in the H2 gas pressure, germanium mole fraction, temperature, pocket length, interface trap charges (ITC), oxide thickness variation, and comparison of different catalytic metals on the drain current performance. The reported sensor exhibits a much-improved drain current sensitivity and current ratio sensitivity compared to the CPTFET gas sensor.