Sensitivity Analysis of a Double Source Stack Lateral TFET-Based Gas Sensor

Abstract

Metal oxide semiconductor gas sensors are used recently in various roles and sectors for environmental safety as compared to other sensing technology due to its low cost, durability, longevity, and rapid sensing capability under humid condition. The current work proposes a dual stacked heterogeneous source lateral n type tunnel field-effect transistor (DSHS-nTFET) for gas sensing applications. The proposed device investigates the characteristics of the gas response. The stack source is designed to make it easier for electrons to tunnel through the tunnel barrier effectively so that the device sensitivity can be enhanced. In the device’s tunneling junction, the presence of the source stack boosts the electric field, reduces tunneling width, and then enhances the band-to-band tunneling. The gas density can be detected by modulating the work function of the metal gate present in the device. Catalytic metals used as gate contacts for this proposed double source stacking TFET design are explored for the purpose of detecting specific gases. Platinum (Pt), Cobalt (Co), Palladium (Pd), and Silver (Ag) are the metal gate electrodes utilised in this work to sense the target gases, like Carbon-mono Oxide (CO), Ammonia (NH3), Hydrogen (H2), and Oxygen (O2) respectively. The detection has been done by the electrodes work function variation due to the presence of gas density of the target gases. With the aid of the Sentaurus TCAD simulator, the suggested structure has been examined for a number of electrical parameters including electric field, surface potential, drain current, and numerous sensing characteristics pertaining to adsorption of gas molecules. According to the data achieved, the suggested DSHS-nTFET device displays a high Ion of 5.06 × 10−5 A/μ m, a low Ioff current of 3.76 × 10−20 A/μm, and also the Ion/Ioff ratio in the range of 1014. Furthermore, sensitivity parameters for DSHS-nTFET have also been examined and shown to be significantly improved. The sensitivity and reliability of the proposed sensor have also been investigated with respect to temperature fluctuations. It has been shown that the device is largely stable over the 200 K-400 K range.