Role of Quasi-Fermi potential in modeling III-V TFETs: InAs as a case study

• Published in: Ain Shams Engineering Journal Vol. 14; no. 7; p. 102007
• Main Authors: Ahmed Shaker, Islam Sayed, Mohamed Abouelatta, Wael Fikry, S. Marwa Salem, Mohamed El-Banna
• Format: Journal Article
• Language: English
• Published: Elsevier 01-07-2023
• Subjects: Band-to-band tunneling (BTBT); Electron Quasi-Fermi Potential (eQFP); InAs DG-TFET; Physically-based model
• ISSN: 2090-4479
• DOI: 10.1016/j.asej.2022.102007

TFET accurate physically based models are highly required to analyze and predict the device characteristics for its future utilization in circuits. In order to precisely model TFETs, it is essential to understand the several aspects related to the physics-based modeling of these devices. Using 2D TCAD simulation, we showed that in order to appropriately model the electrostatic potential in InAs-based TFETs, the electron quasi-Fermi potential (eQFP) should be taken to depend on biasing conditions, both VDS and VGS, contrary to the case of Si-based TFETs in which the eQFP is considered independent of VGS which is widely encountered in the literature. The study is carried out for InAs double-gate homojunction tunnel FETs (DG-TFETs). In addition, we applied the main key factor of dependence of eQFP on a modified TFET model and it is revealed that the interpretation of eQFP correctly predicts the electrostatic potential and the drain-to-source band to band tunneling current.