Scanning Tunneling Microscopy and its Application

Transcription

1 Chunli Bai Scanning Tunneling Microscopy and its Application With 181 Figures SHANGHAI SCIENTIFIC & TECHNICAL PUBLISHERS Jpl Springer

2 Contents 1. Introduction Advantages of STM Compared with Other Techniques From Optical Microscopy to Scanning Tunneling Microscopy Electron Microscopes Field Ion Microscope Scanning Tunneling Microscope Overview 7 2. The Tunneling Effect Historical Remarks Tunneling-Current Theory Tunneling Current Practical Tip and Surface Wave Functions Tip-Surface Interaction Model Tunneling Current Tunnel Conductance Tunneling Active Orbital at the Tip Double-Tip and Interference Effects Spectroscopy, and Spectroscopic Imaging Concepts of Tunneling Spectroscopies Solid-State-Barrier Tunneling Metal-Vacuum-Metal Tunneling Experimental Modes Current-Voltage Characteristics Current-Separation and Separation-Voltage Characteristics Constant-Current Topography Current-Imaging Tunneling Spectroscopy Energy Resolution Examples Surface States Adsorbate-Covered Surfaces Superconductivity Outlook 53 a) Influence of the Tip 54 b) Interpretation of Spectroscopy Results 54 VII

3 4. STM Instrumentation The Vibration Isolation System Mechanical Designs Piezoelectric Ceramics Three-Dimensional Scanners Coarse Sample Positioning STMs for Operation in Various Environments Tip Preparation Preparation of Tungsten Tips Preparation of Pt-Ir Tips Other Ways to Prepare STM Tips Tip Treatment Electronics Computer Automation Hardware Software Image Processing 91 a) Histogram Equalization 92 b) Convolution Filter 92 c) Statistical Differencing 93 d) Three-Dimensional Representation Other Related Scanning Probe Microscopes Atomic Force Microscope The Force Sensor Deflection Detection Illustrating AFM Applications Other Scanning-Force Microscopies HI Lateral Force Microscope Ill Force Microscope Operating in the Noncontact Mode Force Microscope Operating in the Tapping Mode Magnetic Force Microscope Electrostatic Force Microscope Ballistic-Electron-Emission Microscopy The Principle of ВЕЕМ The ВЕЕМ Experiment The Application of ВЕЕМ Ballistic-Hole Spectroscopy of Interfaces Scanning Ion-Conductance Microscope The Scanning Thermal Microscope Scanning Tunneling Potentiometry and Scanning Noise Microscopy Photon Scanning Tunneling Microscopy and Scanning Plasmon Near-Field Microscopy 136 VIII

4 5.8 Near-Field Scanning Optical Microscopy and Spectroscopy Principles of Near-Field Optics Optical Probes for Near-Field Optics NSOM Operation Near-Field Scanning Optical Spectroscopy Near-Field Optical Chemical Sensors Scanning Exciton Microscopy Single-Molecule Detection by Near-Field Optics STM Studies of Clean Surfaces Metal Surfaces Geometric Structures Electronic Structures Surface Diffusion Elemental Semiconductor Surfaces The Si(111) Surface 157 a) Si(lll)-7X7 157 b) Si(lll)-2xl The Si(001) Surface 161 a) Geometric Structure 161 b) Electronic Structure 163 c) The 2xn Structure Other Silicon-Surface Structures The Ge Surfaces 167 a) Ge(lll) 167 b) Ge(001) The GeSi(111) Surface Compound Semiconductors and Layered Compounds GaAs Surfaces 171 a) GaAs(llO). 171 b) GaAs(lOO) 172 c) GaAs(lll)andGaAs(Ill) 173 d) GaAs-AlGaAs Layered Compounds Charge-Density Waves in Compound Semiconductors. 177 a) CDW Phases of lt-tas b) Charge-Density Wave Defects High-T c Oxides Surf ace Adsorbates and Surf ace Chemistry Adsorption on Metal Surfaces Cu(110)-O Cu(100)-O Dynamics 189 IX

5 x Ag(110)-O Ni(110)-HandNi(lll)-H Sulfur Adsorption Cu(lll)-S Ni(lll)-S Cu(110)-S Ni(110)-S Mo(001)-SandRe(0001)-S Other Non-metal Adsorbates on Metals Metallic Adsorbates Adsorption on Semiconductor Surfaces Ag/Si(lll) Au/Si(lll) Cu/Si(lll) Group-Ill Metals on Si(111) B/Si(lll) Cl/Si(lll) Bi on Si(100) and Si(l 11) Surfaces Na/Si(lll) Na/GaAs(110)andCs/GaAs(110) Alkali Metals on Si(100)-2xl Molecules, and Molecular Adsorbates Molecular Crystals Chemisorbed Aromatic Molecules in Ultrahigh Vacuum Physisorbed Molecules in Ultrahigh Vacuum Physisorbed Long-Chain Molecules Fullerenes 227 a) C 60 on GaAs(llO) 227 b) C 60 on Si(100) 228 c) C 60 onsi(lll) 228 d) C 60 on MoS 2 (0001) 228 e) C 60 on Cu(lll) 229 f) C 60 onau(lll)andag(lll) Langmuir-Blodgett Films Observation of Clusters Metal Clusters Semiconductor Clusters Nucleation and Growth Epitaxial Growth of Metal Films Growth of SionSi(OOl) Chemical Reactions on Metals Reaction on Ni(l 10) Reaction on Cu(110) Chemical Identity with STM 242

6 7.7 Chemical Reaction on Semiconductors Reaction of NH 3 with Si(lll)-7x7 Surfaces Reaction of NH 3 with B/Si( 111)- л/3 xv3 Surf ace Reaction of NH 3 with Clean Si(OOl) Surface Si(lll)-7x7 Oxidation Si(100)-2xl Oxidation Reaction of H with Si(lll)-7x Reaction of Sb 4 with Si(100) Biological Applications Advantages and Problems Substrates Fixation of Samples onto Substrates Flexibility of Biological Samples Identification and Interpretation of STM Images Preparation Dispersion of Samples on Substrates Fixation of Samples 255 a) Sample Coatings 255 b) Covalently Binding Samples with Strongly Absorbent Groups 255 c) Binding Samples to the Substrate Covalently STM Imaging in Acqueous Solutions Hopping Technique STM Directed by an Optical Microscope Nucleic Acids DNA in Air and in Vacuum DNA Studies Under Water with an Electrolyte DNA-Protein Complex DNA Bases DNA Sequencing by Scanning-Probe Microscopes Proteins Animo Acids and Peptides Structural Proteins Functional Proteins Biological Membranes Imaging Cells and Other Applications Surface Modification Overview Direct Indentation with the Tunneling Tip Modification of Metal Surfaces Modification of Semiconductor Surfaces Nanolithography on Resist Films 287 XI

7 9.4 Nanofabrication in Solution and in Gaseous Environments Nanofabrication in Solution Nanofabrication in Gaseous Environments Atomic-Scale Manipulation Manipulation of Atoms 293 a) Xenon Atoms 293 b) Iron Atom 296 c) Silicon Atom 297 d) Sulfer Atoms Manipulation of Molecules and Clusters 300 a) Carbon Monoxide 300 b) Antimony Molecules 301 c) Decaborane and Other Organic Molecules 302 d) H 2 0 Molecules Fabrication with Other Scanning-Probe Microscopes Machining Thin Films Charge Storage Magnetic Structures and Writing into an Interface The Future 307 References 309 Subject Index 327 XII