Tunnel Field-effect Transistors (TFET): Modelling and Simulation

Research into Tunneling Field Effect Transistors (TFETs) has developed significantly in recent times, indicating their significance in low power integrated circuits. This book describes the qualitative and quantitative fundamental concepts of TFET functioning, the essential components of the problem of modelling the TFET, and outlines the most commonly used mathematical approaches for the same in a lucid language.   Divided into eight chapters, the topics covered include: Quantum Mechanics, Basics of Tunneling, The Tunnel FET, Drain current modelling of Tunnel FET: The task and its challenges, Modeling the Surface Potential in TFETs, Modelling the Drain Current, and Device simulation using Technology Computer Aided Design (TCAD). The information is well organized, describing different phenomena in the TFETs using simple and logical explanations.   Key features:                  ? Enables readers to understand the basic concepts of TFET functioning and modelling in order to read, understand, and critically analyse current research on the topic with ease.                  ? Includes state–of–the–art work on TFETs, attempting to cover all the recent research articles published on the subject.                  ? Discusses the basic physics behind tunneling, as well as the device physics of the TFETs.                  ? Provides detailed discussion on device simulations along with device physics so as to enable researchers to carry forward their study on TFETs.     Primarily targeted at new and practicing researchers and post graduate students, the book would particularly be useful for researchers who are working in the area of compact and analytical modelling of semiconductor devices. INDICE: Chapter 1: Quantum Mechanics .1.1 Introduction to Quantum Mechanics .1.1.1 The Double Slit Experiment .1.1.2 Basic Concepts of Quantum Mechanics .1.1.2.1 Wavefunctions .1.1.2.2 Born Interpretation .1.1.2.3 Measurement .1.1.2.4 Operators .1.1.2.5 Eigenfunctions .1.1.3 Schrodinger s Equation .1.1.3.1 Formulation of the Equation .1.1.3.2. Probability Current .1.2 Basic Quantum Physics Problems .1.2.1 Free Particle .1.2.1.1 Wavefunction .1.2.1.2. Probability Current .1.2.2 Particle in a 1D box .References .Chapter 2: Basics of Tunnelling .2.1 Understanding Tunnelling .2.1.1 Qualitative Description .2.1.2 Rectangular Barrier .2.2 WKB Approximation .2.3 Landauer s Tunnelling Formula .2.4 Advanced Tunnelling Models .2.4.1 Nonlocal Tunnelling Models .2.4.2 Local Tunnelling Models .2.4.2.1. Kane s Model .2.4.2.2. Hurkx Model .References .Chapter 3: The Tunnel FET .3.1 Device structure .3.1.1 The Need for Tunnel FETs .3.1.2 Basic TFET Structure .3.2 Qualitative Behaviour .3.2.1 Band Diagram .3.2.1.1. Thermal Equilibrium .3.2.1.2. OFF–State .3.2.1.3. ON–State .3.2.1.4. Pinning of the Channel Potential .3.2.1.5. Ambipolar Behaviour .3.2.1.6. Effect of varying the Drain Voltage .3.2.2 Device Characteristics .3.2.2.1. Transfer Characteristics .3.2.2.2 Subthreshold characteristics of MOSFET versus TFET .3.2.2.3. Output Characteristics .3.2.2.4. Delayed Saturation in Output Characteristics .3.2.3 Performance dependence on device parameters .3.2.3.1 Doping .3.2.3.2. Gate Work function .3.2.3.3. Gate Oxide .3.3 Types of TFETs .3.3.1 Planar TFETs .3.3.1.1 Double Gate TFET .3.3.1.2. Dual Material Gate TFET .3.3.1.3. p–n–p–n TFET .3.3.1.4. Raised Ge–source TFET .3.3.1.5. Hetero–junction TFET .3.3.1.6. Ferroelectric TFET .3.3.2 3D TFETs .3.3.2.1 Gate All Around Nanowire TFET .3.3.1.2. Tri–gate/Fin TFET .3.3.3 Carbon nanotube and graphene TFETs .3.3.4 Point versus line tunneling in TFETs .3.4 Other steep subthreshold transistors .References .Chapter 4: Drain current modelling of Tunnel FET: The task and its challenges .4.1 TFET modelling approach .4.1.1 Finding the value of yC .4.1.2 Modelling the surface potential in the source–channel junction. .4.1.3 Finding the tunnelling current .4.2 MOSFET Modelling approach .References .Chapter 5: Modeling the Surface Potential in TFETs .5.1 The Pseudo–2D method .5.1.1 Parabolic approximation of Potential distribution .5.1.2 Solving 2D Poisson s equation using parabolic approximation .5.1.3 Solution for the surface potential .5.2 The Variational approach .5.2.1 The variational form of Poisson s equation .5.2.2 Solution of the Variational form of the Poisson s equation in a TFET .5.2.2.1 Evaluating the Lagrangian .5.2.2.2 Minimizing the Lagrangian .5.2.2.3 Empirical formulation of characteristic length .5.3 The infinite series solution .5.3.1. Solving 2D Poisson s equation using separation of variables .5.3.2 Solution of homogenous boundary value problem .5.3.3 The solution to the 2D Poisson s equation in a TFET .5.3.4 The infinite series solution to the Poisson s equation in a TFET .5.4 Extension of surface potential models to different TFET structures .5.4.1. DG TFET .5.4.2 GAA TFET .5.4.3 Dual Material Gate TFET .5.4.3.1. Pseudo–2D model for a Dual Material Gate TFET .5.4.3.2 Infinite series method for DMG TFET .5.5 The Effect of Localized charges on the surface potential .5.4 Surface Potential in the Depletion Regions .5.5 Use of Smoothing Functions in the Surface Potential Models .References .Chapter 6: Modelling the Drain Current .6.1 Non–Local Methods .6.1.1 Landauer s Tunnelling Formula in TFETs .6.1.2 WKB Approximation in TFETs .6.1.3 Obtaining the Drain Current .6.2 Local Methods .6.2.1 Numerical Integration .6.2.2 Shortest Tunnelling Length .6.2.3 Constant polynomial term assumption .6.2.4 Tangent Line Approximation .6.3 Threshold Voltage Models .6.3.1 Constant Current Method .6.3.2 Constant Tunnelling Length .6.3.3 Transconductance Change (TC) Method .References .Chapter 7: Device simulation using ALTAS .7.1 Simulations using ATLAS .7.1.1 Inputs and Outputs .7.1.2 Structure Specification .7.1.3 Material parameters and Model specification .7.1.4 Numerical method specification .7.1.5 Solution specification .7.2 Analysis of Simulation Results .7.3 SOI MOSFET Example .References .Chapter 8: Simulation of TFETs .8.1 SOI TFET .8.2 Other tunneling models .8.2.1 Schenk band–to–band tunneling model .8.2.2 Non–local band–to–band tunneling .8.3 Gate All Around Nanowire TFET .References .Index

• ISBN: 978-1-119-24629-9
• Editorial: Wiley–Blackwell
• Encuadernacion: Cartoné
• Páginas: 200
• Fecha Publicación: 02/12/2016
• Nº Volúmenes: 1
• Idioma: Inglés