Design and Investigation of a Single Gate Heterostructure Junctionless Tunnel FET for the Gas Detection

Abstract

In this paper, a single gate junctionless heterostructure TFET gas sensor (SiGe-SG-JLTFET) is presented, and its effectiveness is examined. The high-k gate dielectric (HfO2) and low bandgap alloy prove to be a great combination to boost the drain current. The leakage current is controlled by the presence of a silicon body in the channel and drain. We have considered a Palladium metal with a suitable work-function in the gate catalyst for better sensitivity purposes. The sensor modulates the flat band voltage and Capacitance-Voltage characteristics with the adsorption of gas atoms at the Palladium/HfO2 and Palladium surfaces. Consequently, the ON-state current is affected, which is treated as a sensing measure. The gas sensor’s electrostatic analysis is investigated in terms of I-V characteristics, current components, band energy for both ON- and leakage conditions, maximum electric field, BTBT rate, and carrier concentrations. Similarly, the sensitivity analysis consists of drain current sensitivity (SID), current ratio sensitivity (Sratio), and average SS sensitivity (SSS). The investigation has been carried out with the change in gas pressure in terms of work-function, temperature (0K), and interface trap charges (ITC) using a TCAD device simulator. The proposed gas sensor exhibits a (SID)max of 2.41 × 106 and Sratio of 3.89 × 104 with higher pressure concentration at room temperature respectively.