Extended Defects in Semiconductors: Electronic Properties, Device Effects and Structures

Half-title......Page 3
Title......Page 5
Copyright......Page 6
Dedication and History......Page 7
Contents......Page 9
Preface......Page 13
1.1 Materials development and crystal growth techniques......Page 15
1.1.2 Cyberconductors......Page 16
1.1.3 Epitaxy......Page 19
1.1.4 Crystal perfection......Page 21
1.2 Electron energy levels and energy bands......Page 24
1.2.1 The broadening of energy levels into bands......Page 25
1.2.2 The dependence of electrical conductivity on energy band structure......Page 27
1.2.3 Band theory and chemical bonding......Page 28
1.3.1 Adamantine semiconductors as electron compounds......Page 29
1.3.2 III-V and other families of adamantine semiconductors......Page 31
1.4.1 Space lattices, crystal structures, unit cells and symmetry elements......Page 34
1.4.2 The diamond structure......Page 38
1.4.4 The wurtzite structure......Page 40
1.5 Symmetry, Bloch waves and energy band theory......Page 41
1.5.1 Translational symmetry and Bloch's theorem......Page 42
1.5.2 Electron energy bands......Page 44
1.5.3 Effects of point symmetry......Page 45
1.5.4 Momentum-space and reciprocal lattices......Page 46
1.5.5 Brillouin zones and constant energy surfaces......Page 48
1.5.6 The form of the forbidden energy gap......Page 51
1.6.1 Cross substitution and ternary compounds......Page 52
1.6.2 Semiconductor alloys......Page 54
1.6.3 Bonds and bands......Page 56
1.7 Energy band engineering......Page 59
1.7.1 Heterojunctions and energy band alignment......Page 60
1.7.2 Low-dimensional structures for devices......Page 64
1.7.3 Multiquantum well materials......Page 67
1.7.4 Quantum cascade lasers......Page 68
Non-crystalline silicon for solar cells......Page 72
1.8 Materials development and materials competition......Page 74
1.8.2 Technology feedback......Page 75
1.8.4 Integration......Page 76
1.8.6 Current developments......Page 80
References......Page 81
Semiconductor growth......Page 85
2 An introduction to extended defects......Page 87
2.1.1 Extended (structural) defects in semiconductors......Page 88
2.2.1 Volume defects......Page 89
2.2.3 Line defects (dislocations)......Page 90
2.3 Dislocations, plastic deformation and slip systems......Page 91
2.3.1 The Burgers vector......Page 93
2.3.3 Edge and screw dislocations......Page 95
2.3.5 The energy of dislocations......Page 96
2.3.7 Dissociation and extended dislocations......Page 98
2.3.8 The crystallography of slip......Page 100
2.3.10 Dislocations and grain boundaries......Page 102
Epitaxy......Page 104
Pseudomorphism, the 15% rule and the Frank and van der Merwe model......Page 105
The modes of epitaxial growth......Page 108
Ball-and-wire modelling of misfit dislocations......Page 109
2.3.12 Dislocations and point defects......Page 110
Jogs and kinks and point defect generation......Page 113
Impurities and the Cottrell atmosphere......Page 115
2.4 Electrical effects of dislocations in semiconductors......Page 117
2.5 Plasticity of semiconductors......Page 118
2.5.2 The Peierls stress and the double-kink mechanism......Page 119
2.5.3 The force on a dislocation......Page 121
2.5.4 Semiconductor dislocation dynamics......Page 123
2.5.5 Modification of dislocation behaviour by the electronic environment......Page 124
2.5.6 The Frank-Read source and the z-mill......Page 126
2.5.7 Process-induced defects......Page 128
2.5.8 The brittle-ductile transition......Page 129
References......Page 131
Symbols......Page 134
3.1 Introduction......Page 136
3.3 Light microscopy......Page 137
3.3.1 Etching, decoration and stress birefringence......Page 138
3.4 Scanning laser beam microscopy techniques......Page 141
3.5 Electron microscopy......Page 142
3.5.1 Types of instrument and their advantages......Page 143
3.6 Transmission electron microscopy......Page 144
3.6.1 High resolution transmission electron microscopy......Page 146
3.6.2 Diffraction contrast transmission electron microscopy......Page 147
3.6.4 The convergent-beam electron diffraction technique......Page 148
3.7 Scanning electron microscopy......Page 150
3.7.1 Signal formation and resolution in the SEM......Page 151
3.7.2 The modes of scanning electron microscopy......Page 154
3.7.3 Scanning deep level transient spectroscopy......Page 157
3.8 Field emission gun scanning transmission electron microscopy......Page 158
3.8.1 Z contrast in FEGSTEM......Page 159
3.9.1 Techniques and applications of x-ray topography......Page 160
3.10.1 Scanning tunnelling microscopy......Page 161
3.10.2 Atomic force microscopy and other SPM techniques......Page 163
3.10.3 Scanning tunnelling luminescence (STL) microscopy......Page 164
3.10.4 Near-field scanning optical microscopy......Page 166
3.12 Positron annihilation spectroscopy......Page 168
Common acronyms for (micro) characterization techniques......Page 170
References......Page 171
4.1 Atomic core structure of dislocations......Page 177
4.1.1 The Hornstra dislocation models......Page 180
4.1.2 The glide and shuffle sets of dislocations......Page 185
Weak beam TEM evidence of dissociation......Page 191
HRTEM evidence on dislocation cores......Page 195
Calculated dislocation core structures......Page 196
Dislocation motion......Page 197
4.1.3 Polarity in the sphalerite and wurtzite structures......Page 198
Polar differences between the opposite faces of {111} slices......Page 199
Polar asymmetries in {100} faces......Page 203
Dislocation polarity in semiconducting compounds, polar bending and indentation rosettes......Page 206
4.1.4 Dislocations in the sphalerite structure......Page 210
4.1.5 Slip systems in the wurtzite structure......Page 213
Ball-and-wire models of dislocations in the wurtzite structure......Page 216
Partial dislocations in the wurtzite structure......Page 220
TEM studies of stacking faults in wurtzite-structure materials......Page 222
The mechanisms of the wurtzite-sphalerite and polytype transformations......Page 224
The energy of stacking faults in wurtzite and sphalerite structure compounds......Page 227
The Suzuki effect......Page 229
Crystallography of stacking faults in wurtzite-structure compounds......Page 230
4.1.6 Dislocations in covalently bonded semiconductors with the NaCl structure......Page 234
Observations of dislocations in lead chalcogenides......Page 235
The Peierls stress and the double-kink mechanism......Page 236
Dislocation mobility......Page 237
4.2.2 Modification of dislocation behaviour by the electronic environment......Page 239
Effects of doping on dislocation mobility......Page 240
Theories of the effects of doping on dislocation velocities......Page 248
Effects of doping on dislocation motion in semiconducting compounds......Page 249
4.2.3 Chemomechanical effects in semiconductors......Page 256
4.3 Dislocations in II-VI compounds......Page 266
4.3.1 The core form and mobilities of dislocations in II-VI compounds......Page 267
4.3.2 Dislocation current flow and the determination of dislocation line charges......Page 269
4.3.3 The photoplastic effect......Page 273
4.3.4 The electroplastic effect......Page 283
4.3.5 Triboluminescence......Page 288
4.4 Plastic deformation and the microdynamical theory of plasticity......Page 292
4.4.1 Dislocation multiplication in semiconductors......Page 294
4.4.2 Microdynamical equations for the initial stages of deformation......Page 295
4.4.4 Microdynamical theory of the yield point......Page 296
4.4.5 Microdynamical theory of the polar bending of GaAs......Page 298
4.5.1 Dislocations and stacking faults: twinning and phase transformations......Page 300
Wurtzite-sphalerite phase transformation (the crystallography of stacking faults in wurtzite structure compounds)......Page 305
4.5.2 Coherent interfaces and dislocations......Page 306
Subsymmetry and coherence: The coincidence lattice......Page 307
Rotation matrices, twins and semicoherent grain boundaries......Page 309
The O-Lattice treatment of crystalline interfaces......Page 312
Symmetry and bicrystallography......Page 313
Interface energy calculations......Page 314
4.5.3 Grain boundaries......Page 315
Core structures of grain boundaries and the Hornstra models......Page 316
Small- and large-angle grain boundaries......Page 317
Impurities and grain boundaries......Page 320
HRTEM observations of GB core structures......Page 329
Crystallographic polarity and GBs in the sphalerite structure......Page 331
Antiphase boundaries......Page 334
Antiphase boundaries in epitaxial films of II-VI and III-V compounds grown on Ge and Si......Page 338
4.6 Epitaxial interfaces and misfit dislocations......Page 345
4.6.1 Materials selection for epitaxy......Page 346
4.6.2 Film thickness and the introduction of misfit dislocations......Page 348
4.6.3 Mechanisms of introduction and types of misfit dislocations......Page 350
4.6.5 Misfit dislocations in the GeSi/Si system......Page 353
4.6.6 Misfit dislocations in the GaAs/Ge and GaAs/Si systems......Page 354
4.6.7 Defects in III-Nitride systems......Page 357
4.7 Dislocations and point defects......Page 359
4.7.1 Dislocation interactions with impurities......Page 363
4.7.2 The role of dislocations and grain boundaries in diffusion......Page 365
Diffusion-induced misfit dislocations......Page 366
Rapid diffusion along grain boundaries and 'dislocation pipes'......Page 367
Decoration......Page 368
Precipitates and dislocation sources......Page 369
4.8 Growth and processing induced defects......Page 371
4.8.1 Grown-in defects......Page 372
Tetrahedral stacking faults in epitaxial silicon......Page 373
Tripyramids......Page 375
Oval defects in epitaxial GaAs......Page 377
Grappes in InP......Page 378
Micropipes and nanopipes in SiC and GaN......Page 379
4.8.2 Processing induced defects......Page 381
Mechanical damage......Page 384
Oxidation-induced stacking faults in silicon......Page 385
References......Page 389
Symbols......Page 424
5.1.1 Introduction......Page 426
5.1.2 Device effects......Page 427
5.1.3 The electrical properties of dislocations......Page 429
5.1.4 Dangling bonds and mid-gap states: the evidence from ESR and DLTS......Page 430
5.1.7 Dislocations in piezoelectric crystals......Page 434
5.1.8 Dislocations and impurities......Page 435
5.1.9 The polarity of dislocations in semiconducting compounds......Page 436
5.1.11 The electrical properties of grain boundaries......Page 438
5.2 The electrical effects of the deformation of semiconductors: the Read theory......Page 439
5.2.1 The statistics of the occupation of dislocation trap states......Page 440
5.2.2 Experimental tests of the Read theory......Page 442
5.2.3 The effect of charged dislocations on the Hall coefficient......Page 443
5.2.4 Experimental verification of the Read theory......Page 444
5.2.5 The Read theory: conclusions......Page 446
5.2.6 Later developments......Page 447
The charge on dislocations in II-VI compounds......Page 448
5.3 Recombination at dislocations......Page 450
5.3.1 Dislocations and photoconductivity......Page 452
5.3.2 Dislocations and luminescence......Page 455
5.3.3 Recombination-enhanced dislocation motion......Page 456
5.4 The effect of dislocations on optical absorption......Page 460
5.5 SEM EBIC microscopy of individual dislocations......Page 462
5.5.1 Phenomenological theory of dislocation EBIC contrast......Page 464
5.5.2 Physical (charge controlled recombination) theory of dislocation EBIC contrast......Page 465
5.5.3 Temperature dependence of dislocation EBIC contrast......Page 468
5.5.4 Fundamental dislocation parameters obtained from EBIC contrast......Page 470
5.5.5 The Shockley-Read-Hall recombination model for dislocation EBIC contrast......Page 473
Charge controlled recombination or independent recombination centres at dislocations?......Page 477
Lifetime contrast of getter zones......Page 479
Contrast due to a repulsive defect potential......Page 480
Contrast due to doping inhomogeneities......Page 481
Early studies......Page 484
ESR, DLTS and SDLTS studies......Page 485
Microscopic methods of study......Page 487
The EBIC and XBIC contrast of dislocations in Si and the nearly universal role of traces of transition metals in Si......Page 490
Passivation of dangling bonds in dislocations and grain boundaries......Page 496
5.6.1 Localized recombination and dark and bright dislocation CL contrast......Page 499
5.6.2 Other forms of dislocation contrast......Page 505
Dislocation emission in diamond......Page 508
Dislocation exciton luminescence in germanium and dislocation impurity-activated CL in silicon......Page 512
Dislocation luminescence in III-V materials......Page 513
Dislocation luminescence in II-VI materials......Page 517
Dislocation excitons and CL emission......Page 521
Polarity dependence of dislocation CL in compounds......Page 522
Deformation triboluminescence in II-VI compounds......Page 526
5.6.4 CL D-line emission and the nearly universal role of traces of transition metals in Si and Si1-xGex......Page 531
5.7 Scanning probe microscopy of extended defects......Page 534
5.8 Effect of dislocations on transport properties of epitaxial heterostructures......Page 536
5.8.2 Effect of dislocations on carrier mobility......Page 537
5.8.4 Dislocation-induced superconductivity?......Page 541
5.9 Summary: the electrical properties of dislocations......Page 544
5.9.1 The electrical effects of debris left behind moving dislocations......Page 546
5.10 The electrical and luminescent effects of grain boundaries in semiconductors......Page 547
5.10.1 Early studies of the electrical and luminescent effects of grain boundaries......Page 548
5.10.2 Carrier transport across grain boundaries......Page 550
5.10.3 Recombination at grain boundaries......Page 555
5.10.4 More recent SEM CL and REBIC analyses of grain boundaries in semiconducting materials......Page 557
5.11.1 Introduction......Page 560
5.11.3 Defects and accelerated device failure mechanisms......Page 561
Excess noise......Page 565
Excess leakage currents......Page 566
5.11.5 Mechanisms of defect-induced failure in devices......Page 568
5.12 Device benefits of dislocations and grain boundaries......Page 572
5.12.1 Gettering......Page 573
5.12.2 Devices based on dislocation luminescence......Page 574
5.12.3 Dislocations and grain boundaries as microelectronic components......Page 576
5.12.4 Devices controlled by grain boundaries......Page 579
References......Page 586
6.2 Impurity precipitation......Page 620
6.3.1 Point defect thermodynamics......Page 621
6.3.2 Non-stoichiometry......Page 623
6.4 Phase separation and ordering in semiconducting compounds and alloys......Page 624
6.5.1 Constitutional supercooling......Page 625
6.5.2 Cell formation......Page 627
6.5.4 Impurity growth striations......Page 629
6.5.5 Swirl defects in silicon......Page 631
6.6 Major persisting issues......Page 634
References......Page 635
Index......Page 639