Design and Performance Analysis of GaAs-based DG JL VTFET for Ammonia Gas Sensing

This study explores a Double Gate (DG) Junctionless Vertical Layer FET (JLVTFET)structure designed with catalytic essence as gate connections and anatomized for ammonia gas sensing. The perpendicular double-sided gate structure ensures improved gate controllability compared to conventional TFETs for band-to-band tunneling (BTBT). Then GaAs are introduced in the channel, improving device sensitivity performance because of its rich drugs like high electron mobility and band gap compared to conventional semiconductors. Silicon P-type pockets are formed near the source region by adjusting the work function values. The n-channel JLVTFET is analyzed for ammonia gas sensing using Cobalt (Co) and Molybdenum (Mo) as gate materials. The characteristics of the proposed device structure focus on the electric field, surface potential, energy band diagram, and I _d -V characteristics, considering the adsorption of gas molecules. The presence of gas on the gate metal alters the work function, leading to variations in the Off-current (I _off ) On-current (I _on ), and threshold voltage (V _th ), which are considered sensitivity parameters for detecting ammonia gas molecules. Additionally, the channel length and dielectric materials are varied to analyze their impact on the device's sensitivity. A comparison of Silicon-based and GaAs-based DG JL VTFET gas detectors reveals that the GaAs-based device exhibits enhanced sensitivity and an improved on/off current ratio. Simulation results show that these improvements occur by varying the work function of catalytic metal gates, Cobalt and Molybdenum, by 50, 100, 150, and 200 meV.