This book gives a complete overview of the properties of deep-level, localized defects in semiconductors. Such comparatively long-lived (or metastable) defects exhibit complex interactions with the surrounding material, and can significantly affect the performance and stability of certain semiconductor devices. After an introductory discussion of metastable defects, the authors present properties of DX and EL2 centers in IIISHV compounds. They also deal with additional crystalline materials before giving a detailed description of the properties and kinetics of photo-induced defects in amorphous semiconductors. The book closes with an examination of the effects of photo-induced defects in a range of practical applications. The book will be of great use to graduate students and researchers interested in the physics and materials science of semiconductors.
Author(s): David Redfield, Richard H. Bube
Series: Cambridge Studies in Semiconductor Physics and Microelectronic Engineering
Publisher: Cambridge University Press
Year: 1996
Language: English
Pages: 228
Cover......Page 1
Cambridge Studies in Semiconductor Physics
and Microelectronic Engineering: 4......Page 2
TITLES IN THIS SERIES......Page 3
Title......Page 4
Copyright......Page 5
Dedication......Page 6
Contents......Page 8
Preface page ix......Page 10
1.2 General Effects of Defects on Electronic Properties 1......Page 12
1.3 The Need for New Models of Defects 3......Page 14
1.4 Properties of Localized Defects 8......Page 19
1.5 Shallow and Deep Levels 9......Page 20
1.6 Metastable Defects and Configuration-Coordinate Diagrams 11......Page 22
1.7 Energy Bands and Configuration-Coordinate Diagrams 15......Page 26
1.8 Energy Levels and Configuration-Coordinate Diagrams 18......Page 29
1.10 Summary 23......Page 34
2.1 Introduction 24......Page 35
2.2 Large Lattice Relaxation and the DX Center 27......Page 38
2.3 Effects of Pressure and Alloying 31......Page 42
2.4 The Microscopic Model 36......Page 47
2.5 Transition Kinetics 39......Page 50
2.6 EL2 and Other Defects in III-V Compounds 40......Page 51
2.7 Persistent Optical Quenching of Photoconductivity in GaAs 43......Page 54
2.8 Summary of Properties of the DX Center in III-V Compounds 47......Page 58
Decrease in Photoconductivity with Time
in CdS and CdSe......Page 61
Decrease in Photoconductivity with Time
in Copper-Doped CdS......Page 65
Variations in Thermally Stimulated Conductivity......Page 67
Persistent Photoconductivity in CdS......Page 69
Cadmium Telluride......Page 70
Conductivity and Hall Effect......Page 71
Decay of Photoconductivity......Page 72
Optical Cross Section of Neutral Donors......Page 74
Hydrostatic Pressure Effects......Page 75
Summary......Page 76
Undoped II-VI Alloys......Page 77
Doped II-VI Alloys......Page 80
Summary......Page 82
Zinc Selenide......Page 83
3.3 Single-Crystal Silicon 74......Page 85
3.4 Hydrogenated Poly crystalline Silicon 76......Page 87
4.1 Amorphous Semiconductors and Their Defects 79......Page 90
4.2 The Dangling-Bond Defect in a-Si:H 82......Page 93
4.3 Defects and Doping in a-Si:H 88......Page 99
4.4 Description of Dynamic Behavior in Terms of Energy Levels 91......Page 102
4.5 Techniques for the Measurement of Defect Density and Their Limitations 93......Page 104
Constant Photoconductivity Measurements (CPM)......Page 105
Photothermal Deflection Spectroscopy......Page 109
Magnetic Resonance......Page 110
Transient Photo capacitance and Photocurrent......Page 115
4.6 Dependence of Fermi Energy on Defect Density 106......Page 117
4.7 Indications of Dangling-Bond Defects with Different Responses to Light and Heat 111......Page 122
5.1 Kinetics of Generation and Annealing of Photoinduced Defects 113......Page 124
Dispersive Behavior......Page 127
Properties of Stretched Exponentials......Page 129
Use of Stretched Exponentials......Page 132
A Comparison of Formulations......Page 135
5.2 Pulsed-Light-Induced Defects 125......Page 136
Defect Formation in Thin Films of Undoped a-Si:H......Page 139
Relaxation of Defects in Thin Films
of Undoped a-Si:H......Page 142
Measurements on Amorphous Silicon Solar Cells......Page 143
5.4 Defects Induced in the Dark by Carriers 133......Page 144
Defects Induced by Current......Page 145
Defects Induced in Accumulation Layers......Page 146
5.5 Recent Kinetics Results 137......Page 148
5.6 Microscopic Models of Photoinduced Defects in a-Si:H 142......Page 153
Adler's Model......Page 154
Weak-Bond Breaking......Page 155
The Defect Pool Model......Page 156
Non-Equilibrium Defect Densities......Page 159
The Rehybridized Two-Site (RTS) Model......Page 162
Carrier-Induced Defect Formation and Annealing......Page 165
5.7 Photoconductivity Phenomena and Models 156......Page 167
Effect of Doping......Page 168
Fermi-Level Shifts......Page 170
A Simple Photoconductivity Model......Page 171
Doping......Page 173
Fermi-Level Shifts......Page 174
The μτ Problem......Page 176
Other Photoconductivity Phenomena and Models......Page 177
Estimates of Capture Cross Sections......Page 179
Dual-Beam Photoconductivity......Page 180
Effect of Surface Recombination......Page 181
Compensated a-Si:H......Page 182
Thermally Induced Metastability......Page 183
a-Si!_xSx:H Doped Alloys......Page 184
6.1 DX Centers in Amorphous AlGaAs Films 175......Page 186
6.3 Amorphous Ge:H 177......Page 188
6.4 Amorphous Silicon Alloys 178......Page 189
6.5 Amorphous Silicon Nitride 180......Page 191
6.6 Amorphous Chalcogenides 184......Page 195
Photodarkening Effect......Page 196
Decrease of Photoconductivity with Time......Page 197
7.1 Introduction 189......Page 200
7.2 Devices Using III-V Compounds 190......Page 201
7.3 Devices Using II-VI Compounds 192......Page 203
7.4 Solar Cells Using Amorphous Silicon 193......Page 204
7.5 Thin-Film Transistors Using Amorphous Silicon 197......Page 208
7.6 Xerography 198......Page 209
References 201......Page 212
Index 215......Page 226
