Brinda Bhowmick

By Brinda Bhowmick and Rupam Goswami

This chapter presents bandgap-modulated tunnel field effect transistor (TFET) and discusses its simulation and modeling. A geometry of TFET, the heterojunction TFET, is considered, and different electrical parameters are discussed using Technology Computer Aided Design (TCAD) tool. The effect of the heterojunction on the characteristics is observed through the variations in the length and mole fraction of the pocket layer adjacent to the source. An analytical model is further presented for gate-drain underlap TFET using 2-D Poisson equation and Kane’s interband tunneling model. The results are validated with the output from the TCAD tool.

Part of the book: Design, Simulation and Construction of Field Effect Transistors

By Rupam Goswami and Brinda Bhowmick

This chapter presents tunnel field effect transistors (TFETs) as dielectric-modulated (DM) label-free biosensors, and discusses various aspects related to them. A brief survey of the dielectric-modulated TFET biosensors is presented. The concept of dielectric modulation in TFETs is discussed with focus on principle and design perspectives. A Technology Computer Aided Design (TCAD) based approach to incorporate embedded nanogaps in TFET geometries along with appropriate physics-based simulation models are mentioned. Non-ideal conditions in dielectric-modulated biosensors are brought to light, keeping in view the practical considerations of the devices. A gate engineered TFET is taken up for analysis of sensitivities under different conditions through TCAD simulations. Finally, a status map of the sensitivities of the most significant works in dielectric-modulated label-free biosensors is depicted, and the status of the proposed TFET is highlighted.

Part of the book: Design, Simulation and Construction of Field Effect Transistors