Performance and sensitivity analysis of dielectric engineered GAA-JL MOSFET for chloroform gas detection

Abstract

This paper demonstrates a simulation-based analysis of highly sensitive gas sensor design to detect the Chloroform gas based on an advanced Gate All Around Junctionless MOSFET (GAA-JLMOS). In this design, traditional polysilicon gate is replaced with Iridium-Rhodium/Palladium nano-composite (Ir-Rh/Pd) which is responsible for a linear shift in gate work-function in presence of chloroform gas. The work-function modification results into the changes in drain current (I_d) and threshold voltage (V_th), showing a reliable detection from no gas to 50 ppm CHCl₃concentrations by MOS sensor. Additionally, the subthreshold swing optimization leads to faster switching and response times. The simulation results showa significant improvement in the sensitivity of proposed sensor compared to conventional MOS based designs. This manuscript proposes better selectivity towards the detection of chloroform vapors compared to the existing MOS based gas sensors. The simulation results meet a 2x times increase in threshold voltage and 100x times reduction in the leakage current from no gas to 50 ppm concentration of CHCl₃. The proposed GAA-JLMOS shows high sensitivity, low leakage current, and enhanced scalability, providing a possible pathway toward next-generation nanoscale gas sensors. An ATLAS 3D TCAD simulator is used for the sensor design and simulations.