Nano-CMOS Gate Dielectric Engineering

by Wong; Hei

• ISBN13: 9781439849590
• ISBN10: 1439849595
• Edition: 1st
• Format: Hardcover
• Copyright: 2011-11-28
• Publisher: CRC Press

Summary

This book is a systematic review of high-K gate dielectric materials for CMOS chips (complementary metaloxide semiconductors), which are used in image sensors and data convertors (amplifiers, digital camera sensors, etc). Scaling CMOS devices down to the nanoscale creates new materials challenges, and one effective response is to introduce novel materials such as High K dielectrics. The book presents the fundamental physics and properties of High-K materials and how they can be fabricated and used in Nano CMOS devices.

Table of Contents

Foreword	p. vii
Preface	p. xi
List of Abbreviations	p. xiii
Overview of CMOS Technology	p. 1
Introduction	p. 1
MOS Transistor: A Quick Introduction to Classical Models	p. 3
Current-Voltage Characteristics	p. 3
Threshold Voltage	p. 6
Short-Channel Effects and Short-Channel Modifications	p. 9
Effect on I-V Characteristics	p. 10
Subthreshold Conduction	p. 11
Short-Channel Effects	p. 13
Threshold Voltage Roll-Off	p. 15
Drain-Induced Barrier Lowering (DIBL)	p. 15
Gate Leakage Current	p. 17
Dkect-Tunneling	p. 18
Fowler-Nordheim Tunneling	p. 19
Poole-Frenkel Emission and Trap-Assisted Tunneling	p. 20
Features and Uniqueness of MOS Transistor	p. 22
MOS in Deca-Nanometer	p. 24
Technology Trends and Options	p. 30
Technology Trends	p. 30
Technology Options	p. 31
Device Structures	p. 32
Channel Engineering	p. 34
Source and Drain Engineering	p. 37
Gate Stack Engineering	p. 38
More than Moore	p. 41
Summary	p. 43
References	p. 44
High-k Dielectrics	p. 51
High-k Candidates	p. 51
Electronic Structure of Transition Metals and Rare Earth Metals	p. 54
Electronegativity	p. 54
Bond Radius	p. 56
Material Properties of Elemental Transition Metal and Rare Metal Oxides	p. 57
Atomic and Electronic Structures	p. 57
Electronic Structure of Some High-k Oxides	p. 62
Electronic Structure of Aluminum Oxide	p. 62
Electronic Structure of Crystalline Hafnium Oxide	p. 64
Electronic Structure of Crystalline Zirconium Oxide	p. 67
Electronic Structure of Rare Earth Metal Oxides	p. 68
Bandgap and Band Offset Energies	p. 74
Bond Ionicity and Dielectric Constant	p. 77
Carrier Effective Masses	p. 79
Thermal Stability	p. 81
Crystallization	p. 81
Decomposition and Si Out-Diffusion	p. 83
Disorders and Defects	p. 86
Intrinsic Oxygen Vacancies	p. 88
Oxygen Interstitials	p. 94
Grain Boundary States	p. 96
Extrinsic Defects	p. 97
High-k/Si Interface Traps	p. 103
Summary	p. 104
References	p. 105
Complex Forms of High-k Oxides	p. 113
Introduction	p. 113
Silicates and Alurninates Pseudo-Binary Alloys	p. 114
Stoichiometric Binary Alloys	p. 118
Doping	p. 120
Thermal Stability and Phase Separation	p. 128
Summary	p. 130
References	p. 134
Dielectric Interfaces	p. 139
Introduction	p. 139
High-k/Sihcon Interface	p. 140
Interfacial Bonding	p. 140
Bond Strain, Relaxation, and Phase Diagrams	p. 148
Band Offsets	p. 152
High-k/Metal Interface	p. 154
Need of Metal Gate	p. 154
Band Offset Energies	p. 156
Interface Stability	p. 157
Summary	p. 161
References	p. 161
Impacts on Device Operation	p. 167
Introduction	p. 167
Gate Leakage Current	p. 167
Current Conduction Mechanisms	p. 168
Parameters Governing the Charge Transport	p. 171
Threshold Voltage Control and Fermi-Level Pinning	p. 173
Channel Mobility	p. 180
Subthreshold Characteristics	p. 182
Dielectric Breakdown	p. 186
Hot-Carrier Effects	p. 189
Temperature Instabilities	p. 193
Summary	p. 196
References	p. 196
Fabrication Issues	p. 203
Process Integration	p. 203
Atomic Layer Deposition	p. 207
Metal Organic Chemical Vapor Deposition	p. 211
Physical Vapor Deposition	p. 212
Etching	p. 213
Summary	p. 215
References	p. 215
Conclusions	p. 221
Fundamental Physical Constants and Unit Conversions	p. 225
Properties of Si and SiO2	p. 227
Index	p. 229
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