Sensitivity Assessment of RingFET Architecture for the Detection of Gas Molecules: Numerical Investigation

Abstract

TCAD-based numerical investigation of RingFET has been presented in this paper for the detection of gas molecules. Sensitivity of the device has been assessed by calculating the change in off-state current with the change in gate work-function (which changes due to the presence of gas molecule). The behavior of the device has also been compared with the equivalent bulk MOSFET and it was observed that RingFET architecture shows 23% higher sensitivity against gas molecules than equivalent bulk MOSFET. Also, the degradation in device sensitivity with applied drain bias is higher in bulk MOSFET. Optimization in the sensitivity parameter has been done by using different channel materials like GaN, InGaN, and GaAs. Compared to GaAs and silicon, GaN-based RingFET is more sensitive towards gas molecules in the sub-threshold region (due to the wider band gap) besides having lower drain current than GaAs and silicon-based RingFET.