Investigation of Tunnel Field Effect Transistor for Biosensing Applications

Tunnel Field Effect Transistors have been a subject of tremendous recognition in past few years of research in the field of semiconductor devices. Offering various advantages like steep subthreshold slope, low leakage currents, and immunity against short channel effects, these devices have been emerging as an alternative to conventional MOSFETs. In recent years, Tunnel Field Effect Transistors have also acquired recognition in bio sensing applications. The basic phenomenon behind FET based biosensors, is based on the gating effect of the charged molecules on the gate oxide, which can be observed by the change in electrical properties such as conductance, current, threshold voltage etc. Sensitivity is a critical parameter in assessing the performance of bio sensors. Conventional FET based biosensors suffer from theoretical limitations on maximum sensitivity and least detection time. Due to its various advantages, TFET based biosensors exhibit improved sensitivity over CFET sensors. This work proposes a TFET based bio sensor, and device characteristics are modulated based on intrinsic properties such as charge density, dielectric constant, and pH of biomolecules. It is shown that TFETs based biosensor exhibit improved sensitivity with a lesser response time, which make them a promising candidate for biomedical diagnosis applications. The structure has been analysed using TCAD simulations.