Publication

Abstract : In this work, for the first time, the catalytic metal gate (CMG) based nanosheet Field Effect Transistor (NSFET) and nanosheet Tunnel Field Effect Transistor (NSTFET) are proposed for nano-scale device dimensions, and the different design aspects of catalytic metal gate (CMG)-based transduction for Hydrogen (H2) sensing are extensively investigated using numerical device simulation. The influence of applied biasing conditions and structural parameter specifications on the sensing performance of CMG-NSFET and CMG-NSTFET are methodically analyzed from device electrostatics and carrier transport mechanisms. Furthermore, the relative maximum sensitivity variations with H2-partial pressure, ambient temperature, and the presence of ambient Oxygen are comprehensively studied. The study reveals that compared to CMG-NSFET, the CMG-NSTFET demonstrates a high immunity against bias and doping variations, with a notably higher (> 50%) sensitivity within low H2 partial pressures (10−15 – 10−10 Torr). Next, the sensing performance of CMG-NSTFET is systematically optimized through a band-gap and gate-stack engineering approach, leading to a 180% to 650% sensitivity improvement from lower (10−15 Torr) to higher (10−5 Torr) range of H2 partial pressure. Finally, the performance of optimized CMG-NSFET and CMG-NSTFET are extensively benchmarked against other reported nanostructured CMG-FET and TFET-based H2 gas sensors, exhibiting a notably higher sensitivity in the proposed sensors.