This book discusses modern-day Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) and future trends of transistor devices. This book provides an overview of Field Effect Transistors (FETs) by discussing the basic principles of FETs and exploring the latest technological developments in the field. It covers and connects a wide spectrum of topics related to semiconductor device physics, physics of transistors, and advanced transistor concepts. This book contains six chapters. Chapter 1 discusses electronic materials and charge. Chapter 2 examines junctions, discusses contacts under thermal-equilibrium, metal-semiconductor contacts, and metal-insulator-semiconductor systems. Chapter 3 covers traditional planar Metal Oxide Semiconductor Field Effect Transistors (MOSFETs). Chapter 4 describes scaling-driving technological variations and novel dimensions of MOSFETs. Chapter 5 analyzes Heterojunction Field Effect Transistors (FETs) and also discusses the challenges and rewards of heteroepitaxy. Finally, Chapter 6 examines FETs at molecular scales. * Links the discussion of contemporary transistor devices to physical processes * Material has been class-tested in undergraduate and graduate courses on the design of integrated circuit components taught by the author * Contains examples and end-of-chapter problems Field Effect Transistors, A Comprehensive Overview: From Basic Concepts to Novel Technologies is a reference for senior undergraduate / graduate students and professional engineers needing insight into physics of operation of modern FETs. Pouya Valizadeh is Associate Professor in the Department of Electrical and Computer Engineering at Concordia University in Quebec, Canada. He received B.S. and M.S. degrees with honors from the University of Tehran and Ph.D. degree from The University of Michigan (Ann Arbor) all in Electrical Engineering in 1997, 1999, and 2005, respectively. Over the past decade, Dr. Valizadeh has taught numerous sections of five different courses covering topics such as semiconductor process technology, semiconductor materials and their properties, advanced solid state devices, transistor design for modern CMOS technology, and high speed transistors.