A temperature‐dependent surface potential‐based algorithm for extraction of threshold voltage in homojunction TFETs

Abstract

In this paper, we propose an algorithm to extract threshold voltage in homojunction tunnel field effect transistors (TFETs). Single gate TFET and double gate TFET are the geometries which are considered for verification of the method. Firstly, a generalized model of surface potential based on 2D Poisson equation for homojunction TFETs is developed. Secondly, the algorithm involves a number of geometrical operations on surface potential plots, which are performed computationally. From the plots of surface potential and the geometrical constructions, a parameter, range_point, is defined through mathematical formulations. The threshold voltage is determined by subjecting the range_point to a set of constraints which are found to be same for both the devices. The validity of the algorithm is confirmed by considering different parameters like drain voltage, gate oxide thickness, and temperature for both low‐k and high‐k gate dielectric materials in TFETs. The temperature variation is validated for a heterojunction TFET too using the same generalized model of surface potential.

Band Gap Modulated Tunnel FET

“…The advantage of this algorithm is that the procedure is completely computational, and the threshold voltage can be determined without deriving the transfer characteristics. Moreover, the method can be extended to fit different threshold voltage extraction methods by changing the fitting parameter [17].…”

“…The method involves the construction of a tangent at the point on the Figure 10. Algorithm for the extraction of threshold voltage in heterojunction and homojunction TFETs [17].…”