This chapter deals with the more complex short-channel MOSFETs. Most circuits are built with short-channel devices because of their higher current and lower capacitance. Among the main topics are short-channel effects, scale length model, velocity saturation, and non-local transport. A ballistic MOSFET model is described on the current limit of a MOSFET. Next considered are the major device design issues in a CMOS technology: choice of threshold voltage based on the off-current requirement and on-current performance, power supply voltage, design of nonuniform channel doping, and discrete dopant effects on threshold voltage. The last section discusses high-field effects in a short-channel MOSFET.

Chapter 3 covers the basic physics and operation of p−n junctions and Schottky diodes as well as metal−silicon contacts in general. p−n junctions are basic building blocks of bipolar transistors and key components of MOSFETs. Basic knowledge of their characteristics is a prerequisite to further understand the operation of bipolar devices and for designing MOSFETs. And basic knowledge of Schottky diodes is a prerequisite to understand metal−silicon contacts in general and for designing ohmic contacts with low contact resistance. The chapter ends with a discussion of high-field effects in reverse-biased diodes.

The major factors governing the performance of bipolar transistors in circuit applications are discussed in Chapter 11. Several of the commonly used figures of merit, namely, cutoff frequency, maximum oscillation frequency, and logic gate delay, are examined, and how a bipolar transistor can be optimized for a given figure of merit is discussed. Sections are devoted to examining the important delay components of a logic gate, and how these components can be minimized. The scaling properties of vertical bipolar transistors for high-speed digital logic circuits are discussed. A discussion of the optimization of bipolar transistors for RF and analog circuit applications is given. The chapter concludes with a discussion of the design tradeoff and optimization of symmetric lateral bipolar transistors for RF and analog circuit applications. Finally, several unique opportunities offered by symmetric lateral bipolar transistors, some of them beyond the capability of CMOS, are discussed.

Chapter 4 covers the fundamentals of MOS capacitors – a prerequisite to MOSFET transistors. Starting with the basic concepts of free electron level and work function, the chapter proceeds to the solution of charge and potential in silicon, followed by a full description of the C–V characteristics. Quantum mechanical effects, important for MOS capacitors of thin oxides, are then discussed. Added in the third edition is a new section on interface states and oxide traps. Lastly, the high field section covers tunneling currents, high-κ gate dielectrics, and gate oxide reliability.

The introductory chapter begins by reviewing the history and evolution of VLSI technology over the past seventy-five years. Recent developments are then summarized, followed by a brief description of the chapters in the book.