Graphene is very popular because of its many fascinating properties, but its lack of an electronic bandgap has stimulated the search for 2D materials with semiconducting character. Transition metal dichalcogenides (TMDCs), which are semiconductors of the type MX2, where M is a transition metal atom (such as Mo or W) and X is a chalcogen atom (such as S, Se or Te), provide a promising alternative. Because of its robustness, MoS2 is the most studied material in this family. TMDCs exhibit a unique combination of atomic-scale thickness, direct bandgap, strong spin–orbit coupling and favourable electronic and mechanical properties, which make them interesting for fundamental studies and for applications in high-end electronics, spintronics, optoelectronics, energy harvesting, flexible electronics, DNA sequencing and personalized medicine. In this Review, the methods used to synthesize TMDCs are examined and their properties are discussed, with particular attention to their charge density wave, superconductive and topological phases. The use of TMCDs in nanoelectronic devices is also explored, along with strategies to improve charge carrier mobility, high frequency operation and the use of strain engineering to tailor their properties. Two-dimensional transition metal dichalcogenides (TMDCs) exhibit attractive electronic and mechanical properties. In this Review, the charge density wave, superconductive and topological phases of TMCDs are discussed, along with their synthesis and applications in devices with enhanced mobility and with the use of strain engineering to improve their properties.

2D transition metal dichalcogenides

The compelling demand for higher performance and lower power consumption in electronic systems is the main driving force of the electronics industry's quest for devices and/or architectures based on new materials. Here, we provide a review of electronic devices based on two-dimensional materials, outlining their potential as a technological option beyond scaled complementary metal-oxide-semiconductor switches. We focus on the performance limits and advantages of these materials and associated technologies, when exploited for both digital and analog applications, focusing on the main figures of merit needed to meet industry requirements. We also discuss the use of two-dimensional materials as an enabling factor for flexible electronics and provide our perspectives on future developments.

Electronics based on two-dimensional materials

Physical Review B

International Technology Roadmap for Semiconductors 2003の要求清浄度について － シリコンウエハ表面と雰囲気環境に要求される清浄度, 分析方法の現状について －

In the quest for higher performance, the dimensions of field-effect transistors (FETs) continue to decrease. However, the reduction in size of FETs comprising 3D semiconductors is limited by the rate at which heat, generated from static power, is dissipated. The increase in static power and the leakage of current between the source and drain electrodes that causes this increase, are referred to as short-channel effects. In FETs with channels made from 2D semiconductors, leakage current is almost eliminated because all electrons are confined in atomically thin channels and, hence, are uniformly influenced by the gate voltage. In this Review, we provide a mathematical framework to evaluate the performance of FETs and describe the challenges for improving the performances of short-channel FETs in relation to the properties of 2D materials, including graphene, transition metal dichalcogenides, phosphorene and silicene. We also describe tunnelling FETs that possess extremely low-power switching behaviour and explain how they can be realized using heterostructures of 2D semiconductors. Field-effect transistors (FETs) with semiconducting channels made from 2D materials are known to have fewer problems with short-channel effects than devices comprising 3D semiconductors. In this Review, a mathematical framework to evaluate the performance of FETs is outlined with a focus on the properties of 2D materials, such as graphene, transition metal dichalcogenides, phosphorene and silicene.

Two-dimensional semiconductors for transistors

Publisher Summary
This chapter describes the modeling approaches developed for the simulation of germanium devices. The main focus is on metal-insulator-semiconductor (MIS) devices and on germanium-on-insulator (GOI) structures. Most of the approaches were originally developed for silicon devices, and thus the chapter describes the silicon devices highlighting the differences between Si and Ge and their translation in different modeling requirements. The chapter determines the drain current in MIS devices for both n-channel and p-channel transistors. The chapter also discusses the band-structure calculation. The chapter focuses on the calculation of the energy states in 2D systems.

Chapter 9 – Device Modeling

Here, we present an analytical procedure to extract the anisotropy constants of antiferroelectric (AFE) materials from a few key features of the experimental polarization versus field curves. Our approach is validated for two experimental datasets of ZrO2 capacitors, and the extracted parameters are consistent with the microscopically nonpolar nature of the zero-field state of the AFE ZrO2. The methodology has applications in AFE nonvolatile memories and memristors, as well as in electron devices exploiting the negative capacitance (NC) operation of ZrO2.

https://ieeexplore.ieee.org/ielx7/16/4358746/10104153.pdf

Analytical Procedure for the Extraction of Material Parameters in Antiferroelectric ZrO2

This paper investigates the effect of spatially localized versus uniform strain on the performance of n-type InAs nanowire Tunnel FETs. To this purpose we make use of a simulator based on the NEGF formalism and employing an eight-band k·p Hamiltonian, describing the strain implicitly as a modification of the band-structure. Our results indicate that, when the uniform strain degrades the subthreshold slope because of an increased band-to-band-tunneling at the drain, a localized strain at the source side can achieve a better tradeoff between on-current and subthreshold slope than a uniform strain configuration.

Investigation of localized versus uniform strain as a performance booster in InAs Tunnel-FETs

BipFLASH : A novel non-volatile memory cell concept for high-speed, low-power applications

We investigate the interplay between the series (S) and parallel (P) equivalent circuit representations of the MOS system conductance (G) and capacitance (C) in inversion. Experimental and simulated data for Si and InGaAs MOSCAPs are firstly analyzed mathematically. It is found that by interpreting the measured data in both the series and parallel mode, five independent values are obtained for the magnitude and frequency of the maxima and minima points of the −ωdCS,P/dω and GS,P/ω functions versus angular frequency (ω). The significance and application of the approach is presented and discussed.

David Esseni

Papers

Chapter 9 – Device Modeling

Analytical Procedure for the Extraction of Material Parameters in Antiferroelectric ZrO2

Investigation of localized versus uniform strain as a performance booster in InAs Tunnel-FETs

BipFLASH : A novel non-volatile memory cell concept for high-speed, low-power applications

On the interpretation of MOS impedance data in both series and parallel circuit topologies