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Library | Item Barcode | Call Number | Material Type | Item Category 1 | Status |
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Searching... | 30000010163026 | QD96.A8 A32 2008 | Open Access Book | Book | Searching... |
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Summary
Summary
The monographic book addresses the basics of the charge carrier photoemission from one solid to another - the internal photoemission, (IPE) - and different spectroscopic applications of this phenomenon to solid state heterojunctions. This is the first book in the field of IPE, which complements the conventional external photoemission spectroscopy by analysing interfaces separated from the sample surface by a layer of a different solid or liquid. IPE is providing the most straightforward and, therefore, reliable information regarding the energy spectrum of electron states at interfaces. At the same time, the method provides the unique capability of analysing the heterostructures relevant to the modern micro- and nano-electronic devices as well as new materials involved in their design and fabrication.In addition to the discussion of fundamental physical and technical aspects of IPE spectroscopic applications, several "hot" topics are addressed. These include development of new insulating materials for advances Si MOS technology (both high-k gate insulators and low-k dielectrics for interconnect insulation), metal gate materials, development of heterostructures based on high-mobility semiconductors, etc. Thanks to a considerable activity in this field over the last few years, the recent results concerning band structure of most important interfaces involving novel materials can now be documented.
Author Notes
Professor V. Afanas'ev devoted more than 25 years of research to development of novel experimental methods for interface characterization. In particular, a number of techniques based on internal photoemission phenomena were shown to provide unique information regarding electron states in thin films of solids and at their interfaces. In recent years these methods were successfully applied to characterize novel semiconductor heterostructures for advanced micro- and nano-electronic devices.
Table of Contents
Preface | p. xi |
List of Abbreviations | p. xiii |
List of Symbols | p. xv |
1 Preliminary Remarks and Historical Overview | p. 1 |
1.1 General Concept of IPE | p. 1 |
1.2 IPE and Materials Analysis Issues | p. 2 |
1.3 Interfaces of Wide Bandgap Insulators | p. 5 |
1.4 Metal-Semiconductor Barriers | p. 8 |
1.5 Energy Barriers at Semiconductor Heterojunctions | p. 12 |
1.6 Energy Barriers at Interfaces of Organic Solids and Molecular Layers | p. 14 |
1.7 Energy Barriers at Interfaces of Solids with Electrolytes | p. 18 |
2 Internal versus External Photoemission | p. 23 |
2.1 Common Steps in Internal and External Photoemission | p. 23 |
2.1.1 Optical excitation | p. 24 |
2.1.2 Transport of excited electron to the surface of emitter | p. 25 |
2.1.3 Escape from emitter: the Fowler model | p. 29 |
2.2 IPE-Specific Features | p. 32 |
2.2.1 Effects of the collector DOS | p. 32 |
2.2.2 Effects associated with occupied electron states in the collector | p. 34 |
2.2.3 Interface barrier shape | p. 35 |
2.2.4 Electron scattering in the image-force potential well | p. 39 |
2.2.5 Effects of fixed charge in the collector | p. 42 |
2.2.6 Collector transport effects | p. 45 |
3 Model Description and Experimental Realization of IPE | p. 48 |
3.1 The Quantum Yield | p. 48 |
3.2 Quantum Yield as a Function of Photon Energy | p. 50 |
3.3 Quantum Yield as a Function of Electric Field | p. 53 |
3.4 Conditions of IPE Observation | p. 57 |
3.4.1 Injection-limited versus transport-limited current | p. 57 |
3.4.2 Thermoionic emission versus photoemission | p. 59 |
3.4.3 Photocurrents related to light-induced redistribution of electric field | p. 60 |
3.5 Experimental Approaches to IPE | p. 62 |
3.5.1 IPE sample design | p. 62 |
3.5.2 Optical input designs | p. 64 |
3.5.3 IPE signal detection | p. 65 |
4 Internal Photoemission Spectroscopy Methods | p. 67 |
4.1 IPE Threshold Spectroscopy | p. 68 |
4.1.1 Contributions of different bands to IPE | p. 68 |
4.1.2 The Schottky plot analysis | p. 72 |
4.1.3 Separation of different contributions to photocurrent | p. 73 |
4.2 IPE Yield Spectroscopy | p. 75 |
4.2.1 Mechanism of the yield modulation | p. 76 |
4.2.2 Application of the IPE yield modulation to Si surface monitoring | p. 78 |
4.2.3 Model for the optically induced yield modulation | p. 82 |
4.3 Spectroscopy of Carrier Scattering | p. 85 |
4.3.1 Scattering in emitter | p. 85 |
4.3.2 Scattering in collector | p. 88 |
4.4 PC and PI Spectroscopy | p. 92 |
4.4.1 Intrinsic PC of collector | p. 92 |
4.4.2 Spectroscopy of PI | p. 97 |
4.4.3 PI of near-interface states in collector: the pseudo-IPE transitions | p. 101 |
5 Injection Spectroscopy of Thin Layers of Solids: Internal Photoemission as Compared to Other Injection Methods | p. 107 |
5.1 Basic Approaches in the Injection Spectroscopy | p. 108 |
5.2 Charge Injection Using IPE | p. 109 |
5.3 Carrier Injection by Tunnelling | p. 112 |
5.4 Excitation of Carriers in Emitter Using Electric Field | p. 114 |
5.5 Electron-Hole Plasma Generation in Collector | p. 117 |
5.6 What Charge Injection Technique to Choose? | p. 121 |
6 Trapped Charge Monitoring and Characterization | p. 124 |
6.1 Injection Current Monitoring | p. 124 |
6.2 Semiconductor Field-Effect Techniques | p. 127 |
6.3 Charge Probing by Electron IPE | p. 133 |
6.4 Charge Probing Using Trap Depopulation | p. 137 |
6.5 Charge Probing Using Neutralization (Annihilation) | p. 141 |
6.6 Monitoring the Injection-Induced Liberation of Hydrogen | p. 145 |
7 Charge Trapping Kinetics in the Injection-Limited Current Regime | p. 148 |
7.1 Necessity of the Injection-Limited Current Regime | p. 148 |
7.2 First-Order Trapping Kinetics: Single Trap Model | p. 150 |
7.3 First-Order Trapping Kinetics: Multiple Trap Model | p. 152 |
7.4 Effects of Detrapping | p. 154 |
7.5 Carrier Recombination Effects | p. 158 |
7.6 Trap Generation During Injection | p. 160 |
7.7 Trapping Analysis in Practice | p. 161 |
8 Transport Effects in Charge Trapping | p. 164 |
8.1 Strong Carrier Trapping Regime | p. 164 |
8.2 Carrier Trapping Near the Injecting Interface | p. 169 |
8.3 Inhibition of Trapping by Coulomb Repulsion | p. 172 |
8.4 Carrier Redistribution by Coulomb Repulsion | p. 177 |
8.5 Injection Blockage and Transition to Space-Charge-Limited Current | p. 180 |
9 Semiconductor-Insulator Interface Barriers | p. 182 |
9.1 Electron States at the Si/SiO[subscript 2] Interface | p. 183 |
9.1.1 Si/SiO[subscript 2] band alignment | p. 183 |
9.1.2 Si/SiO[subscript 2] interface dipoles | p. 184 |
9.1.3 Si/SiO[subscript 2] barrier modification by trapped charges | p. 186 |
9.1.4 Trapped ions at Si/SiO[subscript 2] interface | p. 188 |
9.2 High-Permittivity Insulators and Associated Issues | p. 189 |
9.2.1 Application of high-permittivity insulators | p. 189 |
9.2.2 Bandgap width in deposited oxide layers | p. 192 |
9.3 Band Alignment at Interfaces of Silicon with High-Permittivity Insulators | p. 195 |
9.3.1 Band alignment at interfaces of Si with elemental metal oxides | p. 195 |
9.3.2 Interfaces of Si with complex metal oxides | p. 198 |
9.3.3 Interfaces of Si with non-oxide insulators | p. 203 |
9.4 Band Alignment between Other Semiconductors and Insulating Films | p. 208 |
9.4.1 Ge/high-permittivity oxide interfaces | p. 209 |
9.4.2 GaAs/insulator interfaces | p. 212 |
9.4.3 SiC/insulator interfaces | p. 217 |
9.5 Contributions to the Semiconductor-Insulator Interface Barriers | p. 221 |
10 Electron Energy Barriers between Conducting and Insulating Materials | p. 224 |
10.1 Interface Barriers between Elemental Metals and Oxide Insulators | p. 225 |
10.1.1 Metal-SiO[subscript 2] interfaces | p. 225 |
10.1.2 Interfaces of elemental metals with high-permittivity oxides | p. 227 |
10.2 Polycrystalline Si/Oxide Interfaces | p. 231 |
10.3 Complex Metal Electrodes on Insulators | p. 237 |
10.4 Modification of the Conductor/Insulator Barriers | p. 242 |
11 Spectroscopy of Charge Traps in Thin Insulating SiO[subscript 2] Layers | p. 245 |
11.1 Trap Classification through Capture Cross-Section | p. 246 |
11.2 Electron Traps in SiO[subscript 2] | p. 248 |
11.2.1 Attractive Coulomb traps | p. 248 |
11.2.2 Neutral electron traps in SiO[subscript 2] | p. 249 |
11.2.3 Repulsive electron traps in SiO[subscript 2] | p. 251 |
11.3 Hole Traps in SiO[subscript 2] | p. 251 |
11.3.1 Attractive Coulomb hole traps | p. 252 |
11.3.2 Neutral hole traps in SiO[subscript 2] | p. 252 |
11.4 Proton Trapping in SiO[subscript 2] | p. 256 |
12 Conclusions | p. 260 |
References | p. 263 |
Index | p. 291 |