Sensitivity analysis on stack gate-dielectric GaAs tri gate FinFET based oxygen gas sensor

This paper proposes a new FinFET device with two gate dielectrics placed as stack and GaAs material as semiconductor material. This device is designed in such a way that it can be used as O-2 gas sensor. In the proposed FinFET, Silver metal (Ag) is used as a gate metal for sensing the gas molecules. Primarily, the performance of the proposed FinFET is compared in terms of on current (I-ON), off current (I-OFF) and the Subthreshold Swing (SS) with the conventional Silicon based FinFET. The proposed FinFET shows better performance not only in terms of electrical characteristics, but also it shows more Sensitivity (S) compared to Si based FinFET. The use of Ag gate metal on the proposed FinFET shows better Sensitivity (S) compared to the conventional Si based FinFET. With the diffusion of O-2 gas molecules on the gate metal, the work function of the gate changes, thus, the I-ON, I-OFF, threshold voltages and the potential are also change and can be considered as the Sensitivity parameter for sensing the gas molecules. Thus, upon considering the better result of proposed FinFET, the further analysis as sensing applications has been carried out for proposed GaAs based FinFET. The Sensitivity of the device is also analyzed by varying the dimensional parameters such as fin width, gate length and for the different dielectric materials. This work is based on numerical calculations using the TCAD program.