Compact Modeling of Multi-Layered MoS₂ FETs Including Negative Capacitance Effect

Abstract

In this article, we present a channel thickness dependent analytical model for MoS2 symmetric double-gate FETs including negative capacitance (NC) effect. In the model development, first thickness dependent model of the baseline 2D FET is developed, and later NC effect is included in the model using the Landau-Khalatnikov (L-K) relation. To validate baseline model behavior, density functional theory (DFT) calculations are taken into account to obtain numerical data for the K and Λ valley dependent effective masses and differences in the energy levels of N-layer (N = 1, 2, 3, 4, and 5) MoS2. The calculated layer dependent parameters using DFT theory are further used in a drift-diffusion simulator to obtain electric characteristics of the baseline 2D FET for model validation. The model shows excellent match for drain current and total gate capacitance of baseline FET and NCFET against the numerical simulation.

Keywords

• Metal-oxide-semiconductor field-effect transistor (MOSFET)
• compact modeling
• molybdenum disulfide (MoS₂)
• transition metal dichalcogenide (TMD)
• double gate (DG)
• negative capacitance FET (NCFET)