Simulation and analysis of ZnO- based extended-gate gate-stack junctionless NWFET for hydrogen gas detection

The sensitivity of the hydrogen gas detector can be improved by using the extended-gate technique in nanowire FET. A ZnO-based extended-gate gate-stack junctionless nanowire field-effect transistor (EG-GS-JLNWFET) hydrogen gas device is considered for the first time in this work. Catalytic gate metal, palladium (Pd) on high-K dielectric reduces the overall work function; the concept is further used in sensor design. The presence of gate stacking and extended-gate structure together improve the gate controllability, which results in an improved current ratio. Sensitivity parameters, $${S_{{I_{{{\text{ON}}}} }} }$$ and $${S_{{I_{{{\text{OFF}}}} }} }$$ are considered for performance analysis. Results are compared with JLNWFET. The gate-stack junctionless nanowire field- effect transistor (GS-JLNWFET) shows enhancement compared to both the sensitivities in the proposed device. When compared to JLNWFET-based sensor, EG-GS-JLNWFET shows 2.59% and 24.85% improvement, respectively, in the sensitivity with respect to IOFF and ION for a change of 160 meV in the work function of palladium (Pd). Leakage in any device must be as low as possible, as it lowers the standby power losses in the device. In this work, the proposed design has lowered the leakage as compared to the rest of the two structures. The results also show an augmentation in sensitivity with the increase in gate material work function