Growth, Properties and Applications
Buch, Englisch, 608 Seiten, Format (B × H): 175 mm x 251 mm, Gewicht: 1179 g
ISBN: 978-0-470-69706-1
Verlag: Wiley
Mercury cadmium telluride (MCT) is the third most well-regarded semiconductor after silicon and gallium arsenide and is the material of choice for use in infrared sensing and imaging. The reason for this is that MCT can be ‘tuned’ to the desired IR wavelength by varying the cadmium concentration.
Mercury Cadmium Telluride: Growth, Properties and Applications provides both an introduction for newcomers, and a comprehensive review of this fascinating material. Part One discusses the history and current status of both bulk and epitaxial growth techniques, Part Two is concerned with the wide range of properties of MCT, and Part Three covers the various device types that have been developed using MCT. Each chapter opens with some historical background and theory before presenting current research. Coverage includes:
- Bulk growth and properties of MCT and CdZnTe for MCT epitaxial growth
- Liquid phase epitaxy (LPE) growth
- Metal-organic vapour phase epitaxy (MOVPE)
- Molecular beam epitaxy (MBE)
- Alternative substrates
- Mechanical, thermal and optical properties of MCT
- Defects, diffusion, doping and annealing
- Dry device processing
- Photoconductive and photovoltaic detectors
- Avalanche photodiode detectors
- Room-temperature IR detectors
Weitere Infos & Material
Series Preface xxi
Preface xxiii
Foreword xxvii
List of Contributors xxxi
Part One - Growth 1
1 Bulk Growth of Mercury Cadmium Telluride (MCT) 3
P. Capper
1.1 Introduction 3
1.2 Phase equilibria 4
1.3 Crystal growth 5
1.3.1 Solid state recrystallization (SSR) 6
1.3.2 Traveling heater method (THM) 9
1.3.3 Bridgman 12
1.3.4 Accelerated crucible rotation technique (ACRT) 13
1.4 Conclusions 18
References 19
2 Bulk Growth of CdZnTe/CdTe Crystals 21
A. Noda, H. Kurita and R. Hirano
2.1 Introduction 21
2.2 High-purity Cd and Te 22
2.2.1 Cadmium 22
2.2.2 Tellurium 23
2.3 Crystal growth 23
2.3.1 Polycrystal growth 23
2.3.2 VGF single-crystal growth 24
2.4 Wafer processing 41
2.4.1 Process flow 42
2.4.2 Characteristics 44
2.5 Summary 48
Acknowledgements 48
References 49
3 Properties of Cd(Zn)Te Relevant to Use as Substrates 51
S. Adachi
3.1 Introduction 52
3.2 Structural properties 52
3.2.1 Ionicity 52
3.2.2 Lattice constant and crystal density 53
3.2.3 Spontaneous ordering 54
3.2.4 Structural phase transition 55
3.3 Thermal properties 55
3.3.1 Phase diagram 55
3.3.2 Specific heat and Debye temperature 56
3.3.3 Thermal expansion coefficient 57
3.3.4 Thermal conductivity and diffusivity 57
3.4 Mechanical and lattice vibronic properties 58
3.4.1 Elastic constant and related parameters 58
3.4.2 Microhardness 58
3.4.3 Optical phonon frequency and phonon deformation potential 59
3.5 Collective effects and some response characteristics 61
3.5.1 Piezoelectric constant 61
3.5.2 Fröhlich coupling constant 61
3.6 Electronic energy-band structure 62
3.6.1 Bandgap energy 62
3.6.2 Electron and hole effective masses 64
3.6.3 Electronic deformation potential 65
3.6.4 Heterojunction band offset 66
3.7 Optical properties 67
3.7.1 The reststrahlen region 67
3.7.2 The interband transition region 68
3.7.3 Near or below the fundamental absorption edge 69
3.8 Carrier transport properties 70
3.8.1 Low-field mobility 70
3.8.2 Minority-carrier transport 71
References 71
4 Substrates for the Epitaxial Growth of MCT 75
J. Garland and R. Sporken
4.1 Introduction 76
4.2 Substrate orientation 77
4.3 CZT substrates 78
4.3.1 Effects of poor thermal conductivity on MCT growth 78
4.3.2 Effects of substrate crystalline defects on MCT growth 79
4.3.3 Effects of substrate impurities 80
4.3.4 Effects of nonuniform substrate composition and substrate roughness 80
4.3.5 Effects of surface nonstoichiometry and contaminants 81
4.3.6 Characterization and screening of CZT substrates 81
4.3.7 Use of buffer layers on CZT substrates 82
4.4 Si-based substrates 82
4.4.1 Nucleation and growth of CdTe on Si 83
4.4.2 The effects of As and Te monolayers 84
4.4.3 Advantages of CdTe/Si substrates 85
4.4.4 Disadvantages of CdTe/Si substrates 86
4.4.5 Reduction of the dislocation density 87
4.4.6 Passivation of dislocations 88
4.5 Other substrates 89
4.6 Summary and conclusions 90
References 90
5 Liquid Phase Epitaxy of MCT 95
P. Capper
5.1 Introduction 95
5.2 Growth 96
5.2.1 Introduction 96
5.2.2 Phase diagram and defect chemistry 98
5.2.3 LPE growth techniques 98
5.3 Material characteristics 103
5.3.1 Composition and thickness 103
5.3.2 Crystal quality and surface morphology 105
5.3.3 Impurity doping and electrical properties 106
5.4 Device status 108
5.5 Summary and future developments 108
References 110
6 Metal-Organic Vapor Phase Epitaxy (MOVPE) Growth 113
C. D. Maxey
6.1 Requirement for epitaxy 113
6.2 History 114
6.3 Substrate choices 115
6.3.1 Orientation 115
6.3.2 Material 116
6.4 Reactor design 117
6.5 Process parameters 118
6.6 Metal-organic sources 119
6.7 Uniformity 120
6.8 Reproducibility 120
6.9 Doping 123
6.10 Defects 125
6.11 Annealing 127
6.12 In situ monitoring 127
6.13 Conclusions 128
References 128
7 MBE Growth of Mercury Cadmium Telluride 131
J. Garland
7.1 Introduction 131
7.1.1 The MBE growth technique 132
7.2 MBE Growth theory and growth modes 132
7.2.1 Growth modes 133
7.2.2 Quasiequilibrium theories 133
7.2.3 Kinetic theories 134
7.3 Substrate mounting 135
7.4 In situ characterization tools 135
7.4.1 Reflection high-energy electron diffraction 135
7.4.2 Spectroscopic ellipsometry 136
7.4.3 Other in situ characterization tools 139
7.5 MCT nucleation and growth 139
7.6 Dopants and dopant activation 141
7.7 Properties of MCT epilayers grown by MBE 143
7.7.1 Electrical properties 143
7.7.2 Optically measurable characteristics 144
7.7.3 Structural properties 144
7.7.4 Surface defects 145
7.8 Conclusions 146
References 147
Part Two - Properties 151
8 Mechanical and Thermal Properties 153
M. Martyniuk, J. M. Dell and L. Faraone
8.1 Density of MCT 154
8.1.1 Introduction 154
8.1.2 Variation of Density with X 154
8.1.3 Variation of density with temperature 155
8.1.4 Conclusion 158
8.2 Lattice parameter of MCT 158
8.2.1 Introduction 158
8.2.2 Variation of Lattice Parameter with X 158
8.2.3 Variation with temperature 160
8.2.4 Conclusion 162
8.3 Coefficient of thermal expansion of MCT 162
8.3.1 Introduction 162
8.3.2 Variation
