Electronic Materials A New Era in Materials Science

1. Introduction.- References.- 2. The Simplest Ab Initio Theory of Electronic Structure.- 2.1 Tight-Binding Theory.- 2.2 Universal Parameters.- 2.3 A Diatomic Molecule, N2.- 2.4 A Simplification Using Hybrids.- 2.5 Cohesion of N2.- 2.6 Polarizability of N2.- 2.7 Tetrahedral Semiconductor Bonds.- 2.8 Semiconductor Energy Bands.- 2.9 Cohesion in Semiconductors.- 2.10 The Dielectric Properties.- 2.11 Ionic Crystals.- 2.12 Covalency in Ionic Compounds.- 2.13 Transition-Metal Compounds.- 2.14 Summary.- References.- 3. Theory of Electronic Excitations in Solids.- 3.1 Quasiparticle Theory of Electron Excitations.- 3.2 Band Gaps and Excitation Spectra of Bulk Crystals.- 3.3 Surfaces, Interfaces, Superlattices, and Clusters.- 3.4 Model Dielectric Matrix.- 3.5 Summary and Conclusions.- References.- 4. Determination of the Electronic Structure of Solids.- 4.1 Band Mapping with Photoemission and Inverse Photoemission.- 4.2 Understanding Semiconductors from First Principles.- 4.3 Magnetic Storage and Thin Film Magnetism.- 4.4 Optoelectronics and Excited State Spectroscopy.- 4.5 Spatial Resolution.- 4.6 Packaging, Polymers, and Core Levels.- 4.7 Summary.- References.- 5. Predicting the Properties of Solids, Clusters and Superconductors.- 5.1 Background.- 5.2 Surfaces and Interfaces.- 5.3 Total Energies and Structural Properties.- 5.4 Compressibilities and Empirical Theories.- 5.5 Metallic Clusters.- 5.6 Superconductivity.- 5.7 Conclusions.- References.- 6. High-Temperature Superconductivity: The Experimental Situation.- 6.1 Structural and Chemical Nature of the New Materials.- 6.2 The Superconducting State: Macroscopic Properties.- 6.3 Microscopic Superconducting Properties.- 6.3.1 Pairing.- 6.3.2 Pairing Mechanism.- 6.4 Theoretical Considerations and Discussion.- References.- 7. Surface Structure and Bonding of Tetrahedrally Coordinated Compound Semiconductors.- 7.1 Key Concepts in Semiconductor Surface Chemistry.- 7.2 Zincblende (110) Surfaces.- 7.3 Wurtzite Cleavage Surfaces.- 7.3.1 Wurtzite (10 $$\bar 1$$ 10).- 7.3.2 Wurtzite (11 $$\bar 2$$ 20).- 7.4 Adsorption on Zincblende (110) Surfaces.- 7.4.1 Epitaxically Constrained Adsorbate Bonding.- 7.4.2 Process-Dependent Bonding: Reactive Chemisorption.- 7.5 Synopsis.- References.- 8. Formation and Properties of Metal-Semiconductor Interfaces.- 8.1 Experimental Techniques and Analysis.- 8.1.1 Photoelectron Spectroscopy.- 8.1.2 Experimental Procedures.- 8.1.3 Samples and Deposition Procedures.- 8.1.4 Core-Level Lineshape Analysis.- 8.2 Interface Formation at 300 K.- 8.2.1 Co/GaAs.- 8.2.2 Reactive Interfaces.- 8.2.3 Au III-V Interfaces.- 8.3 Low-Temperature Interface Formation.- 8.3.1 Ti/GaAs(110).- 8.3.2 Co/GaAs(110).- 8.3.3 Ag/GaAs(110).- 8.4 Surface Photovoltaic Effects.- 8.4.1 Dependence of Band Bending on Temperature and Bulk Dopant Concentration.- 8.4.2 Photoemission from Metallic Dots.- 8.5 Interface Formations with Metal Ions.- 8.5.1 Ag/ZnSe(100).- 8.5.2 In/GaAs(110) and Ag/InP(110).- 8.6 Interfaces Formed by Metal Cluster Deposition.- 8.6.3 Cluster Morphology.- 8.6.4 Cluster Metallicity and Substrate Modification.- 8.6.5 Cluster-Induced Band Bending.- 8.7 Prospects and Future Developments.- References.- 9. Electronic States in Semiconductor Superlattices and Quantum Wells: An Overview.- 9.1 Envelope-Function Description of Electronic States.- 9.1.1 Generalities.- 9.1.2 Discussion of the Envelope-Function Approximation.- 9.1.3 Examples of Results.- a) GaAs-A1xGa1-x As.- b) InAs-GaSb Superlattices and Quantum Wells.- c) CdTe-HgTe Superlattices.- 9.2 External Fields.- 9.2.1 Generalities.- 9.2.2 Electric Fields.- 9.2.3 Landau Levels: Perpendicular Fields.- 9.2.4 Landau Levels: Parallel Fields.- 9.3 Excitons in Quantum Wells.- References.- 10. Photonic and Electronic Devices Based on Artificially Structured Semiconductors.- 10.1 Resonant Tunneling Bipolar Transistors with a Double Barrier in the Base.- 10.1.1 Design Considerations for RTBTs with Ballistic Injection.- 10.1.2 Quasi-Ballistic Resonant Tunneling in a Tunneling Emitter RTBT.- 10.1.3 Thermionic Injection RTBTs Operating at Room Temperature.- 10.1.4 Speed and Threshold Uniformity Considerations in RTBTs.- 10.2 Devices with Multiple Peak I-V Characteristics and Multiple-State RTBTs.- 10.2.1 Vertical Integration of RT Diodes.- 10.2.2 Multiple-State RTBTs.- 10.2.3 Microwave Performance of Multiple-State RTBTs.- 10.3 Circuit Applications of Multiple-State RTBTs.- 10.3.1 Frequency Multiplier.- 10.3.2 Parity Generator.- 10.3.3 Multistate Memory.- 10.3.4 Analog-to-Digital Converter.- 10.4 Gated Quantum Well and Superlattice-Base Transistors.- 10.4.1 Gated Quantum Well Transistor.- 10.4.2 Superlattice-Base HBT.- 10.4.3 Unipolar Superlattice-Base Transistor.- 10.5 Quasi-Electric Fields in Graded-Gap Materials.- 10.5.1 Electron Velocity Measurements.- 10.6 Heterojunction Bipolar Transistors with Graded-Gap Layers.- 10.6.1 High-Speed Graded-Base Transistors.- 10.6.2 Emitter Grading in Heterojunction Bipolar Transistors.- 10.7 Multilayer Sawtooth Materials.- 10.7.1 Rectifiers.- 10.7.2 Electrical Polarization Effects in Sawtooth Superlattices.- 10.7.3 Staircase Structures.- a) Staircase Solid-State Photomultipliers and Avalanche Photodiodes.- b) Repeated Velocity Overshoot Devices.- 10.8 AlGaAs Floating-Gate Memory Devices with Graded-Gap Injector.- 10.8.1 Integration in Arrays.- References.- 11. Quantum Structural Diagrams.- 11.1 Interatomic Forces.- 11.2 Ionic Crystals.- 11.3 Covalent Crystals.- 11.4 Metallic Compounds and Alloys.- 11.5 Molecular Structure Diagrams.- 11.6 Deductive Calculations.- 11.7 Prospects.- References.- 12. Ion and Laser Beam Processing of Semiconductors: Phase Transitions in Silicon.- 12.1 Ion Implantation.- 12.2 Amorphization and Solid Phase Epitaxy.- 12.3 Ion-Beam Induced Epitaxy, Diffusion and Segregation.- 12.4 Thermodynamic and Kinetic Properties of Amorphous Si.- 12.5 Liquid Phase Crystal Growth and Dopant Segregation.- 12.6 Melting of Amorphous Si: A First-Order Phase Transition.- 12.7 Conclusion: Undercooling and Explosive Crystallization.- 12.8 Update: The State of Amorphous Si.- References.

Modem materials science is exploiting novel tools of solid-state physics and chemistry to obtain an unprecedented understanding of the structure of matter at the atomic level. The direct outcome of this understanding is the ability to design and fabricate new materials whose properties are tailored to a given device ap­ plication. Although applications of materials science can range from low weight, high strength composites for the automobile and aviation industry to biocompat­ ible polymers, in no other field has progress been more strikingly rapid than in that of electronic materials. In this area, it is now possible to predict from first principles the properties of hypothetical materials and to construct artificially structured materials with layer-by-Iayer control of composition and microstruc­ ture. The resulting superlattices, multiple quantum wells, and high temperature superconductors, among others, will dominate our technological future. A large fraction of the current undergraduate and graduate students in science and engi­ neering will be directly involved in furthering the revolution in electronic mate­ rials. With this book, we want to welcome such students to electronic materials research and provide them with an introduction to this exciting and rapidly de­ veloping area of study. A second purpose of this volume is to provide experts in other fields of solid­ state physics and chemistry with an overview of contemporary research within the field of electronic materials.