Two-dimensional model of a heterojunction silicon-on-insulator tunnel field effect transistor

• Heterojunction SOI-TFET with oxide overlap on the Ge-source region is proposed.
• Developed 2D model for the proposed device using an infinite series solution technique.
• Analytical expressions for the electrostatic potential, electric field, and energy band are developed.
• The impact of gate length scaling on the surface potential profile is also studied.
• The electric field is used to calculate the drain current.

In nanoscale regime, Tunnel field effect transistor (TFET) is the most promising candidate as it provides smaller subthreshold swing (SS) and higher Ion/Ioff ratio than conventional MOSFET. We propose a two-dimensional analytical model for a heterojunction silicon-on-insulator (SOI) TFET using an infinite series solution technique. Analytical expressions for the electrostatic potential, electric field, and energy band are developed by solving 2D Poisson's equation under appropriate boundary conditions. The impact of gate length scaling on the surface potential profile is also analyzed and studied. The electric field is used to calculate the drain current. The derived analytical expressions are validated with Synopsys TCAD results.