Charge Plasma Based Si1-xGex Sourced Nanowire Tunnel Field Effect Transistor Oxygen Gas Device with Enhanced Sensitivity

In this paper, Charge Plasma Nanowire Tunnel Field Effect Transistor based sensor is proposed for the recognition of Oxygen (O-2) gas molecules by means of a Silicon Germanium (Si1-xGex) sourced device abbreviated as SiGe-CP-NW-TFET. The electrical performances of SiGe-CP-NW-TFET have been compared with the conventional Charge Plasma Nanowire Tunnel Field Effect Transistor (CP-NW-TFET). The parameters measured for comparison are I-ON, I-OFF, I-ON/I-OFF, Subthreshold slope (SS), and threshold voltage (V-t). The proposed SiGe-CP-NW-TFET has better electrical performance as compared to Si-CP-NW-TFET. Further, the device characteristics such as electric potential, electric field, charge carriers, and energy band diagram of both the devices have also been compared. The fundamental physics of the proposed sensor is also explored from a comprehensive electrostatic study of the tunnelling junction in the context of gas molecule adsorption. The influence of device constraints of the proposed SiGe-CP-NW-TFET on the electrical performance indicators has also been studied. The device parameters e.g. oxide thickness, extended gate length, silicon film thickness, and molar concentration of SiGe at the source side are considered. The impact of oxide thickness, extended gate length, the radius of NW, and the concentration of SiGe (molar) at the source side have been analysed on the sensitivity of the O-2 gas sensor. The presented Oxygen gas sensor has an I-ON/I-OFF ratio of 3.65 x 10(7) and a subthreshold slope of 58.23 mV/decade.