Contributors (Author(s), Editor(s), Translator(s), Illustrator(s) etc.)

Angsuman Sarkar is an assistant professor in the Department of Electronics and Communication Engineering, Kalyani Government Engineering College, West Bengal. He received his MTech degree in VLSI and microelectronics from Jadavpur University, Kolkata, and is now working towards his PhD from the same university. His current research interest is in the study of short channel effects of sub 100 nm MOSFETs and nano device modelling. His publications include research papers in refereed journals and conference proceedings and several textbooks.

Chandan Kumar Sarkar is a professor in the Department of Electronics and Telecommunication Engineering in Jadavpur University, Kolkata. He obtained his MSc degree in Physics from Aligarh Muslim University, Aligarh, his PhD from Calcutta University (1979) and his DPhil from Oxford University, Oxford, UK (1984). Professor Sarkar was a Postdoctoral Fellow supported by the Royal Commission for the Exhibition of 1851 at Clarendon Laboratory of Oxford University. He was also Junior Research Fellow ofWolfson College, Oxford University. He is an active researcher in the area of semiconductor devices and nanoelectronics. He has published a number of research papers in refereed journals and conference proceedings. He has also authored several textbooks and guided many PhD students in electronics engineering. Professor Sarkar is presently IEEE EDS distinguished lecturer and also Chair of the IEEE EDS chapter, Calcutta section, India. He has been Visiting Professor in many universities abroad.

Table of Content

Preface
1 Physics of Semiconductors
1.1 Introduction
1.2 Recapitulation from Previous Studies
1.2.1 Atomic bonding
1.2.2 Covalent bonds
1.2.3 Concept of holes
1.2.4 Intrinsic and extrinsic semiconductors
1.2.5 Elemental and compound semiconductors
1.2.6 Significance of the symbols n+, n, n−, p, p+, p−
1.2.7 Summary of the recapitulations
1.3 Crystal Structure
1.3.1 Various types of solids
1.3.2 Structure of a crystal
1.3.3 Basic crystal structures
1.3.4 Lattice point calculation
1.3.5 Structure of silicon and GaAs
1.3.6 Index system for crystal planes (crystallographic notations)
1.3.7 Crystal direction
1.4 Introduction to Atoms and Electrons
1.4.1 Journey from the classical model to quantum numbers
1.4.2 Limitations of classical physics
1.4.3 Quantum mechanics
1.5 Band Formation theory of Semiconductors
1.5.1 Band formation in silicon
1.5.2 Semiconductors, insulators and metals
1.5.3 Band gap energy
1.5.4 Band structure in compound semiconductors
1.6 E–k Diagram 8
1.6.1 Concept and theory of E–k diagram
1.6.2 Drift current due to movement of electrons
1.6.3 Concept of holes, negative effective mass concept for holes and current due to holes
1.6.4 Direct band gap and indirect band gap semiconductors
1.7 Transport of Carriers
1.7.1 Drift
1.7.2 Diffusion
1.7.3 Diffusion and drift of carriers: Built in or induced field and the Einstein relation
1.7. Pair generation in semiconductors
1.7.5 Recombination process and life time of carriers
1.7.6 Excess carriers and the significance of life time
1.8 Carrier Concentrations and Introduction to Fermi Levels
1.8.1 Different distribution laws
1.8.2 Fermi-Dirac distribution
1.8.3 Metals and insulators with respect to the Fermi–Dirac distribution
1.8.4 Fermi-Dirac distribution for semiconductors
1.8.5 Electrons and hole concentrations at equilibrium
1.8.6 Ionisation energy
1.8.7 Degenerate semiconductors
1.9 Mobility and Scattering
1.9.1 Drift velocity and carrier mobility
1.9.2 Different types of scattering
1.9.3 High field effects and velocity saturation
1.10 Excess Carriers
1.10.1 Injection of excess carriers
1.10.2 Quasi Fermi level
1.10.3 Continuity equation
1.10.4 Steady-state carrier injection and diffusion length
1.11 Appendix
1.11.1 Gauss’s law
1.11.2 Poisson’s equation
1.11.3 Hall effect
1.11.4 Density of states in an energy band

2 Diodes 121
2.1 Introduction
2.2 p-n Junction Under Zero Bias (Unbiased) Conditions
2.2.1 Formation of depletion region
2.2.2 Contact potential
2.2.3 EquilibriumFermi levels
2.2.4 Expression for electric field and space–charge width
2.3 Forward and Reverse Bias
2.3.1 Forward bias
2.3.2 Reverse bias
2.3.3 Drift and diffusion currents in the biased diode
2.4 Current Calculation in p-n Junction
2.4.1 Assumptions for deriving the current expression in a p-n junction
2.4.2 Minority and majority currents in the p-n diode
2.4.3 Static and dynamic resistance
2.5 Applications of p-n Diodes
2.6 Reverse Bias Breakdown 0
2.6.1 Avalanche breakdown 1
2.6.2 Zener breakdown 3
2.6.3 Differences between avalanche and Zener diodes 7
2.7 Tunnel Diode 7
2.7.1 I–V characteristics of tunnel diode 7
2.8 Capacitance of p-n Junctions 9
2.8.1 Junction capacitance 9
2.8.2 Varactor diode 16
2.8.3 Diffusion capacitance 161
2.8.4 One-sided junction 162
2.8.5 Graded junction 163
2.9 Switching Characteristics of a Semiconductor Diode 16
2.9.1 The turn off transient 165
2.9.2 Switching diode 167
2.9.3 Rectifier diode 167
2.10 Metal–semiconductor Contacts 169
2.10.1 Comparison of Schottky and p-n diodes 172
2.10.2 Ohmic contacts 17
2.11 Photovoltaic Effect 176
2.12 Solar Cell 179

3 Bipolar Junction Transistors
3.1 Introduction
3.1.1 Three terminal device and the general concept of a control input terminal
3.2 Simplified Structure and Modes of Operation
3.2.1 Regimes of operation
3.3 Band Diagram of a Transistor
3.4 Various Current Components in an n-p-n BJT
3.5 Bipolar Transistor: A Conceptual Picture
3.6 Transistor Action
3.7 Operation of the n-p-n Transistor in the Active Mode
3.8 How a BJT Provides Amplification
3.8.1 Minority carrier profile and band diagram in different modes
3.9 Equivalent Circuit Model of the Forward Active Mode
3.10 Models of Reverse Active Mode BJT
3.11 Combining Models of Forward Active and Reverse Active: Ebers–Moll Model
3.11.1 First use of Ebers–Moll model: Current in forward active mode
3.11.2 Second use of Ebers–Moll model: Current in the saturation mode
3.12 Load Line and Modes of Operation
3.13 Early Effect or Base Width Modulation
3.14 Common Emitter Characteristics and Common Emitter Current Gain
3. Saturation Voltage and Saturation Resistance
3.16 Common Base Characteristics
3.17 The Collector Saturation Current and Transistor Breakdown
3.17.1 Avalanche multiplication breakdown
3.17.2 Breakdown due to punch-through
3.18 BJT Functioning as an Amplifier and a Switch
3.18.1 Large signal operation
3.18.2 Amplifier gain
3.18.3 Operation as a switch
3.19 Large Signal Model
3.19.1 Small signal operation and models
3.19.2 Concept of transconductance
3.19.3 Small signal collector current and transconductance
3.19.4 Small signal base current and input resistance at the base
3.19.5 Small signal emitter current and the input resistance at the emitter
3.19.6 Small signal voltage gain
3.20 Hybrid _ Model
3.20.1 Inclusion of early effect in the Hybrid _ model
3.21 h(hybrid) Parameter Model
3.22 Kirk Effect
3.23 Collector Current Fall off at Low and High Currents
3.24 Future Trends in BJT Design

4 Junction Field Effect Transistors (JFETs)
4.1 Introduction
4.2 Gate Isolation
4.3 Structure of JFET
4.3.1 Basic JFET operation
4.4 The Working Principle of JFET Explained with Equations
4.5 Ideal dc Current–voltage Relationship
4.6 Comparison Between JFET and BJT
4.7 Parameters of JFET

5 Metal Oxide Semiconductor Field Effect Transistors (MOSFETs)
5.1 Introduction
5.2 Basic Operation
5.2.1 Operation without gate bias
5.2.2 Operation with a positive gate bias
5.2.3 Operation with a small VDS
5.2.4 Operation as VDS is increased
5.3 MOS Capacitor
5.3.1 Accumulation
5.3.2 Depletion
5.3.3 Inversion
5.3.4 Detailed analysis of depletion
5.3.5 Detailed analysis of inversion
5.4 Flat Band Voltage: Effect of Real Surfaces
5.4.1 Equalisation of the Fermi levels
5.4.2 Charges in the oxide
5.4.3 Interface traps
5.4.4 Flat-band voltage
5.5 Expression of Threshold Volt