[paper] Compact Model for MoS2 FETs

A physics-based compact model for MoS2 field-effect transistors

considering the band-tail effect and contact resistance

Yuan Liu¹, Jiawei Zeng², Zeqi Zhu¹, Xiao Dong² and WanLing Deng³

Japan Society of Applied Physics; Accepted Manuscript online 11 September 2020

¹Guangdong University of Technology, Guangzhou, Guangdong, CHINA

²Jinan University, Guangzhou, Guangdong, CHINA
³Electronic Engineering, Jinan University, Guangzhou, GuangDong, 510630, CHINA

Abstract: In this paper, we present a compact surface-potential-based drain current model in molybdenum disulfide (MoS2) field-effect transistors (FETs). Considering variable range hopping (VRH) transport via band-tail states in MoS2 transistors, an explicit solution for surface potential has been derived and it provides a good description over different regions of operation by comparisons with numerical data. Based on charge-sheet model (CSM) which applies to drift-diffusion transport, the current expression including contact resistance and velocity saturation effect is developed. Furthermore, the presented model is validated and shows a good agreement with experiment data for MoS2 FETs. Keywords: molybdenum disulfide (MoS2), surface potential, current expression.

[paper] First Principles Based Compact Model for 2D-Channel MOSFETs

Das, Biswapriyo, and Santanu Mahapatra

First Principles Based Compact Model for 2D-Channel MOSFETs

researchgate.net online publication

Abstract: We propose a generalized compact model for any two-dimensional material channel-based metal-oxide-semiconductor field-effect transistors. Unlike existing ones, the proposed model is first principles based and thus has ability to predict the circuit performance only using the crystallographic information of the channel material. It is ‘core’ in nature and developed following the industry-standard drift-diffusion formalism based ‘top-down’ hierarchy employing the FermiDirac statistics. We also implement the model in professional circuit simulator and good convergence is observed in 15-stage ring oscillator simulation.

Fig: Synopsis of the modeling framework. First, certain material specific parameters are extracted employing density functional theory computations and Hamiltonian calibration, which thereafter are used to develop the compact device model of the 2D-channel MOSFET using drift-diffusion formalism. The drain current and terminal charges obtained henceforth are used to implement digital circuits in commercial circuit simulator using its Verilog-AMS interface. 

[read more...]