Nanocrystals in Nonvolatile Memory: Nanocrystals in Nonvolatile Memory

555 Pages·2018·13.362 MB·\555

by  Writam Banerjee (Editor)

Nanocrystals in
Nonvolatile Memory

Nanocrystals in
Nonvolatile Memory
edited by
Writam Banerjee
Published by
Pan Stanford Publishing Pte. Ltd.
Penthouse Level, Suntec Tower 3
8 Temasek Boulevard
Singapore 038988
Email: [email protected]
Web: www.panstanford.com
British Library Cataloguing-in-Publication Data
A catalogue record for this book is available from the British Library.
Nanocrystals in Nonvolatile Memory
All rights reserved. This book, or parts thereof, may not be reproduced in any form
Copyright © 2018 by Pan Stanford Publishing Pte. Ltd.
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or any information storage and retrieval system now known or to be invented,
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ISBN 978-981-4774-73-4 (Hardcover)
ISBN 978-1-351-20327-2 (eBook)
I dedicate this book to my parents, Mr. Parboti Shankar
Banerjee and Mrs. Gopa Banerjee, whose patience, hard work,
and impressive attitude toward life and family inspired me to
have a strong belief in hope and made me capable of editing
this book. On this note, I must share my point of view about
the magical word “hope.”
I believe,
Every mortal object in this living planet starts its new sun with
the same magical word HOPE.
H stands for Highly,
O stands for Organized or Oriented,
P stands for Positive, and
E stands for Energy.

Contents
Preface
Acknowledgments
xv
1. Nanocrystal Materials, Fabrications, and Characterizations xi1x
Sujan Chowdhury and Puspendu Barik
1.1 Introduction 2
1.1.1 Nanomaterials for a Nonvolatile
Memory Device 4
1.1.2 Overview of Nonvolatile Memory 5
1.1.3 Classification of Nanomaterials 7
1.2 Synthesis and Fabrication of Nanocrystals
for NVM 9
1.2.1 0D Nanocrystals 11
1.2.2 1D Nanocrystals 14
1.2.3 2D Nanocrystals 20
1.2.4 3D Nanocrystals 25
1.3 Characterization of Nanoparticles 26
1.3.1 Microscopy Technique 27
1.3.1.1 Electron microscopy 27
1.3.1.2 Reflection high-energy
electron diffraction 32
1.3.1.3 Scanning probe microscopy 33
1.3.2 X-Ray-Based Methods 37
1.3.2.1 X-ray diffraction 37
1.3.2.2 Small-angle X-ray scattering 38
1.3.2.3 X-ray photoelectron
spectroscopy 40
1.3.2.4 X-ray absorption
spectroscopy 43
1.3.3 Light-Based Spectroscopic Techniques 44
1.3.3.1 Light scattering techniques 45
1.3.3.2 Ultraviolet/visible
spectroscopy 46
1.3.3.3 Photoluminescence
spectroscopy 47
viii Contents
1.3.3.4 Raman spectroscopy 49
1.3.3.5 Fourier transform infrared
spectroscopy 50
2. 1M.4o delinSgu amnmd aSrimy ulation of Nanocrystal Flash Memory 5715
Bikash Sharma and Chandan Kumar Sarkar
2.1 Introduction 76
2.2 Developments in Nanocrystal Memory 79
2.3 Model for Nanocrystal and Nitride-Trap Memory 82
2.4 Memory Device Scaling with the Use of a Silicon
Nanocrystal 87
2.5 Modeling of Tunneling Currents 90
2.6 Model for the Charging and Discharging Process 96
κ
2.7 Programming Time Model 101
2.8 Growth of Metal (Au) Nanocrystals in High-
Dielectrics 104
2.9 Retention Characteristics Model 106
2.10 Tunneling Characteristics of Metal-
Nanocrystal- and Semiconductor-
Nanocrystal-Based Gate Dielectrics 109
2.10.1 Fowler–Nordheim Tunneling 114
2.10.2 Direct Tunneling 115
3. 2Ch.1a1r ge TCroanpcpliunsgi oann d High-κ Nanocrystal Flash Memory 112207
Meng Chuan Lee and Hin Yong Wong
3.1 Introduction to Charge Storage Nonvolatile
Memory 128
3.2 Evolution of Nanocrystal-Based CS-NVM 139
3.3 Reliability Challenges of Nanocrystal-Based
CS-NVM 145
3.4 Technical Mitigations 152
4. 3Si.l5ic on NSaunmomcraysrtya l Flash Memory 116753
Lili Zhao, Tiezheng Lv, and Guofeng Fan
4.1 Introduction 174
4.2 Si NCs in Flash Memory 175
Contents ix
4.2.1 Structure Development of a Si NC
Floating Gate 175
4.2.1.1 Si NC floating-gate story 176
4.2.1.2 Preparation of Si NCs for flash
memory 180
4.2.2 Electrical Characteristics of Si
Nanocrystal in Flash Memory 183
4.3 Si Nanocrystal Trap Center Studied by
Deep-Level Transient Spectroscopy 184
4.4 Engineering for Improved Si Nanocrystal Flash
5. SynthesMis,e Cmhoarrayc terization, and Memory Application 192
of Germanium Nanocrystals in Dielectric Matrices 199
Wee Kiong Choi and Writam Banerjee
5.1 Introduction 200
5.2 Synthesis of Ge Nanocrystals 203
5.2.1 Ge Atoms for Nanocrystal Growth 203
5.2.2 Effect of Ge Concentration and
Annealing Temperature 205
5.2.3 Effect of Annealing Ambient 210
5.2.4 Effect of an Oxide Barrier Layer 211
5.2.5 Influence of Dielectric Matrices 213
5.3 Characterizations of Ge Nanocrystals 216
5.3.1 Photoluminescence Properties 216
5.3.2 Electroluminescence Properties 219
5.3.3 Stress in Ge Nanocrystals Embedded
in Dielectrics 222
5.4 Ge Nanocrystal-Based Floating-Gate Memory
Devices 228
5.4.1 Fabrication of Ge Nanocrystal
Memory Structures 228
5.4.2 Control of Nanocrystal Size 231
κ
5.4.3 Retention Properties 237
5.4.4 High- Dielectrics 242
5.4.5 Characterization Ge-Nanocrystal-
Based Transistors 245
5.5 Summary 253