Theoretical Approach to Polarization Effects in Semiconductors | p. 1 |
Introduction | p. 1 |
Basic Electrostatics | p. 2 |
Polarization | p. 4 |
Ab Initio Calculations of the Electronic Structure | p. 5 |
Modern Theory of Polarization | p. 6 |
Polarization at Interfaces: Interface Dipoles | p. 10 |
Averaging Microscopic Charges and Field | p. 10 |
AlAs/GaAs Superlattice | p. 11 |
Spontaneous Polarization in the Wurtzite Structure: BeO | p. 12 |
GaN/AlN Superlattice: Spontaneous Polarization and Piezoelectricity | p. 13 |
Electric Field-Driven Diffusion and Segregation of Dopants in Superlattices | p. 16 |
Introduction | p. 16 |
Interfacial Segregation | p. 17 |
Profile of H in AlN/GaN Superlattice | p. 19 |
Summary | p. 23 |
References | p. 24 |
Polarization Induced Effects in GaN-based Heterostructures and Novel Sensors | p. 27 |
Introduction | p. 27 |
First-Principles Prediction of Structural and Pyroelectric Properties | p. 29 |
Lattice Constants, Average Bond Length and Bond Angles in Ternary Compounds | p. 30 |
Polarity | p. 40 |
Growth of Undoped AlGaN/GaN, InGaN/GaN and AlInN/GaN Hetero- and Nanostructures | p. 41 |
AlGaN/GaN Heterostructures | p. 41 |
InGaN/GaN Heterostructures | p. 42 |
AlInN/GaN Heterostructures | p. 42 |
Non-Linear Spontaneous and Piezoelectric Polarization in Group-III-Nitrides | p. 42 |
Spontaneous Polarization | p. 43 |
Piezoelectric Polarization | p. 45 |
Polarization Induced Surface and Interface Charges | p. 56 |
Sheet Carrier Concentration of Polarization Induced 2DEGs | p. 61 |
2DEGs Confined at Interfaces of Undoped Ga-face AlGaN/GaN Heterostructures | p. 63 |
2DEGs Confined at Interfaces of Undoped, Ga-face AlInN/GaN Heterostructures | p. 65 |
2DEGs Confined in InGaN/GaN Single Quantum Wells | p. 69 |
Sensors Based on Polarization Induced 2DEGs | p. 74 |
Overview | p. 74 |
Surface Sensitive Sensors | p. 75 |
Mechanical Sensors | p. 92 |
Sensor for Electromagnetic Fields | p. 98 |
Summary | p. 100 |
References | p. 103 |
Lateral and Vertical Charge Transport in Polar Nitride Heterostructures | p. 111 |
Polar Heterostructures: What Do They Offer? | p. 111 |
Polar Heterostructures: Undoped Electronics | p. 112 |
The Applications of Nitrides | p. 113 |
Transport Issues in Nitride Device | p. 115 |
Polar Materials: Use in Sensor Technology-Potential of Merging Polar Materials with Semiconductors | p. 115 |
Theoretical Approach | p. 117 |
Polarization by Strain | p. 117 |
Vertical Junction Transport | p. 119 |
Lateral Transport in Undoped HEMTs | p. 123 |
k [middle dot] p Method for Strained Nitride Quantum Wells and Quantum Dots | p. 127 |
Tailoring of Vertical Junctions | p. 128 |
Gate Leakage Suppression | p. 129 |
Forming Ohmic Contacts by Using Polarization Effects | p. 132 |
Nitride HFETS: Transport Issues | p. 134 |
Nonlinear Access Resistance and GaN Device Operation | p. 135 |
Scaling Issues in Nitride HEMTs | p. 139 |
Smart HFETs: Multi-Functional Devices | p. 142 |
Stress and Strain Calculation | p. 145 |
Pyroelectricity | p. 146 |
Strain Sensor FETs: Results | p. 147 |
Thermal Sensor FETs | p. 150 |
Effects of Defects | p. 152 |
Conclusions | p. 154 |
References | p. 154 |
Polarization Effects on Low-Field Transport & Mobility in III-V Nitride HEMTs | p. 161 |
Introduction | p. 161 |
Polarization-Induced 2DEGs in AlGaN/GaN HEMTs | p. 163 |
Polarization Effects on Charge Transport and Scattering | p. 163 |
Charge Control | p. 164 |
Survey of Experimental 2DEG Mobility Data | p. 169 |
Theoretical Tools to Address AlGaN/GaN 2DEG Mobilities | p. 171 |
Scattering Mechanisms | p. 171 |
Typical AlGaN/GaN 2DEG Structures | p. 171 |
Traditional Scattering Mechanisms | p. 172 |
Novel Scattering Mechanisms in AlGaN/GaN 2DEGs | p. 182 |
Using Theory to Explain Experimental Data | p. 194 |
Summary and Conclusions | p. 198 |
Appendix on the Theory of Low-Field Transport & Mobility | p. 198 |
The Boltzmann Transport Equation | p. 199 |
Mobility-Basic Theory | p. 203 |
Statistics for Two- and Three-Dimensional Carriers | p. 206 |
Screening by Two- and Three-Dimensional Carriers | p. 207 |
Mobility of 2DEGs | p. 208 |
Material Properties of III-V Nitrides Relevant to Transport | p. 211 |
References | p. 214 |
Local Polarization Effects in Nitride Heterostructures and Devices | p. 217 |
Introduction | p. 217 |
Basic Physics of Polarization Effects | p. 217 |
Experimental Determination of Polarization Charge Densities | p. 219 |
Consequences for Heterostructures, Defects, and Devices | p. 224 |
Polarization-Based Engineering of Nitride Heterostructures | p. 225 |
Enhancement of Schottky Barrier Height in HFET Structures | p. 229 |
Polarization-Based Energy Barrier Engineering | p. 230 |
Residual Stress and Piezoelectric Effects in GaN HFETs | p. 235 |
Polarization Effects in Nitride-Based HBTs and p-Type Structures | p. 238 |
Localized Effects of Polarization | p. 243 |
Dislocation-induced Polarization Fields | p. 244 |
Scanning Capacitance Microscopy | p. 245 |
Threshold Voltage Variations in AlGaN/GaN HEMT Structures | p. 246 |
Nanoscale Electronic Structure in InGaN/GaN Quantum Wells | p. 251 |
References | p. 260 |
Polarization in Wide Bandgap Semiconductors and their Characterization by Scanning Probe Microscopy | p. 265 |
Introduction | p. 265 |
Polarization in III-N | p. 266 |
Polarization in Silicon Carbide | p. 268 |
III-N and SiC Heterostructures | p. 269 |
III-N Based Heterostructures | p. 269 |
SiC Based Heteropolytype Structures | p. 271 |
Interface and Surface Charge in SiC and III-N Heterojunctions | p. 274 |
Charges at the Interface and Surface | p. 274 |
Surface States and Their Significance | p. 284 |
SPM Characterization of Heterostructures | p. 285 |
Basics of Kelvin Probe Microscopy | p. 286 |
Characterization of Charge Instability | p. 287 |
Surface States Characterization and Passivation | p. 299 |
Summary | p. 302 |
References | p. 303 |
Functionally Graded Polar Heterostructures: New Materials for Multifunctional Devices | p. 307 |
Introduction | p. 307 |
Graded Polar Nitride Semiconductor Heterostructures | p. 308 |
Polarization in Nitrides: A Tutorial | p. 308 |
Electrostatics and Dipole-Engineering | p. 321 |
Epitaxial Growth and Structural Properties | p. 324 |
Electronic Properties | p. 326 |
Transport Properties of Polarization-induced 3D Electron Slabs | p. 328 |
Quantum Magnetotransport Properties | p. 333 |
Device Applications of Polarization-'Doped' Graded Nitride Layers | p. 340 |
Universal Physics of Functionally Graded Ferroelectric and Ferromagnetic Alloys | p. 345 |
Order Parameters in Ferroic (Ferroelectric, Ferromagnetic, & Ferroelastic) Materials | p. 345 |
Functionally Graded Electrets and Magnets | p. 352 |
Functionally Graded Ferromagnets | p. 366 |
Summary and Challenges | p. 368 |
References | p. 368 |
Polarization in GaN Based Heterostructures and Heterojunction Field Effect Transistors (HFETs) | p. 373 |
Introduction | p. 373 |
Heterojunction Field Effect Transistors (HFETs) | p. 376 |
Polarization Issues as Pertained to HFETs | p. 379 |
Analytical Description of HFETs | p. 397 |
Numerical Modeling of Sheet Charge and Current | p. 409 |
Calculated I-V Characteristics | p. 418 |
Experimental Considerations | p. 419 |
AlGaN/GaN HFET Performance | p. 424 |
Evolution of GaN FET Performance | p. 430 |
Drain Voltage and Drain Breakdown Mechanisms | p. 442 |
Anomalies in GaN MESFETs and AlGaN/GaN HFETs | p. 453 |
References | p. 457 |
Effects of Polarization in Optoelectronic Quantum Structures | p. 467 |
Introduction | p. 467 |
Basic Elements of the Theory of Polarization in III-V Nitride Heterostructures | p. 468 |
The Wurtzite Structure | p. 469 |
Strain and Internal Electric Field in III-Nitride Heterostructures | p. 470 |
Effects of Polarization Fields on Optical Properties of III-V Nitride Quantum Heterostructures | p. 484 |
Experimental Manifestation of Polarization Fields in Group-III Nitride Based Nanostructures | p. 494 |
Experimental Evidence of Polarization Fields | p. 494 |
Polarization Field Measurement | p. 496 |
Optical Properties of GaN/AlGaN Quantum Wells | p. 498 |
Optical Properties of GaN/AlN Quantum Dots | p. 502 |
InGaN/GaN Quantum Wells: The Heart of Nitride Based Optoelectronic Devices | p. 504 |
Conclusion | p. 506 |
References | p. 507 |
Index | p. 513 |
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