Islands, Mounds and Atoms

Crystal growth far from thermodynamic equilibrium is nothing but homoepitaxy - thin film growth on a crystalline substrate of the same material. Because of the absence of misfit effects, homoepitaxy is an ideal playground to study growth kinetics in its pure form. Despite its conceptual simplicity, homoepitaxy gives rise to a wide range of patterns. This book explains the formation of such patterns in terms of elementary atomic processes, using the well-studied Pt/Pt(111) system as a reference point and a large number of Scanning Tunneling Microscopy images for visualization. Topics include surface diffusion, nucleation theory, island shapes, mound formation and coarsening, and layer-by-layer growth. A separate chapter is dedicated to describing the main experimental and theoretical methods. The text is aimed at physicists with an interest in growth kinetics, surface scientists, graduate students, and practitioners of thin film deposition.

Inhalt

1. Introduction.- 1.1 Atoms, Crystals and Visualization.- 1.2 Crystal Growth Far from Equilibrium.- 1.3 Epitaxy.- 1.4 About this Book.- 2. Condensation, Diffusion and Nucleation.- 2.1 Arriving at the Surface: Sticking and Transient Mobility.- 2.2 Moving on: Surface Diffusion.- 2.2.1 The Surface Diffusion Coefficient.- 2.2.2 Transition State Theory.- 2.2.3 Direct Observation of Adatom Diffusion.- 2.2.4 The Onset Method.- 2.2.5 Theoretical Estimates of Diffusion Parameters on Pt(111).- 2.3 Getting Together: Two-Dimensional Nucleation.- 2.3.1 Atomistic Nucleation Theory.- 2.3.2 The Island Size Distribution.- 2.3.3 Experimental Test of Nucleation Theory.- 2.3.4 Binding Energies from Island Densities.- 2.4 Supplementary Topics.- 2.4.1 Condensation on Clusters and at Steps.- 2.4.2 Exchange Diffusion.- 2.4.3 Nucleation and Random Walks.- 2.4.4 Nucleation with Mobile Clusters.- 2.4.5 Adatom-Adatom Interactions and Nucleation Theory.- 2.4.6 Adsorbate Influenced Diffusion and Nucleation.- 3. Island Shapes.- 3.1 Island Shapes and the Hierarchy of Diffusion Processes.- 3.2 The Equilibrium Shape of Adatom and Vacancy Islands.- 3.2.1 Definition and the Wulff Construction.- 3.2.2 Experimental Realization of 2D Equilibrium Shapes.- 3.2.3 The Ising Model and the Awning Approximation.- 3.2.4 Absolute Energy Values for Steps and Kinks.- 3.3 Fractal-Dendritic Islands.- 3.4 Compact, Triangular Islands.- 3.5 Adsorbates and Island Shapes.- 3.6 Shape Instabilities and the Diffusion Field.- 3.7 Supplementary Topics.- 3.7.1 Migration Along Rough Island Edges.- 3.7.2 The Transition from Fractal-Dendritic to Compact Islands: Theory Versus Experiment.- 3.7.3 Stability Criteria for Compact Islands.- 4. Pattern Formation in Multilayer Growth.- 4.1 The Temperature Dependence of Multilayer Growth.- 4.1.1 Growth Modes on Pt(111): TEAS.- 4.1.2 Growth Modes on Pt(111): STM.- 4.1.3 Roughness Measures.- 4.2 Statistical Growth and the Shape of Wedding Cakes.- 4.3 Interlayer Transport.- 4.3.1 The Step Edge Barrier and Some of Its Consequences.- 4.3.2 Theory of Second Layer Nucleation.- 4.3.3 Experimental Determination of the Step Edge Barrier.- 4.3.4 Theoretical Estimates of Step Crossing Rates on Pt(111).- 4.4 Step Atomic Structure and Growth Modes on Pt(111).- 4.4.1 A Model for the Effective Step Edge Barrier.- 4.4.2 Film Thickness Dependence of ?Eeffs at 440K.- 4.4.3 Low Temperature Growth on Pt(111).- 4.4.4 Growth Bifurcation Around 500K.- 4.4.5 CO Adsorption and Mound Growth on Pt(111).- 4.4.6 A Criterion for Mound Growth.- 4.5 Mound Formation with Weak Barriers.- 4.5.1 Diffusion Bias and the Growth-Induced Current.- 4.5.2 Weak Barriers: Onset of the Instability.- 4.5.3 Weak Barriers: Mound Shapes.- 4.6 Long Time Evolution of the Mound Morphology.- 4.6.1 Slope Selection.- 4.6.2 Coarsening.- 4.7 Growth Instabilities of Vicinal Surfaces.- 4.7.1 Stability of a Step Train.- 4.7.2 Step Meandering: The Bales-Zangwill Instability.- 4.7.3 Step Meandering: Experiments and Alternative Mechanisms.- 4.7.4 The Ultimate Fate of Step Flow.- 4.8 Self-Affine Growth.- 4.8.1 Universality Classes of Kinetic Roughening.- 4.8.2 Conserved and Nonconserved Growth.- 4.8.3 Kinetic Roughening and Mound Formation.- 4.9 Supplementary Topics.- 4.9.1 Growth Regimes and Surface Atomic Structure.- 4.9.2 Ripple Formation in Homoepitaxial Growth.- 4.9.3 Derivation of the Step Edge Boundary Condition.- 4.9.4 Second Layer Nucleation and Rate Equations.- 4.9.5 Second Layer Nucleation with Reversible Aggregation.- 4.9.6 Further Experimental Signatures of the Step Edge Barrier.- 4.9.7 Diffusion Bias Without a Step Edge Barrier.- 4.9.8 Continuum Theory of Mound Coarsening.- 4.9.9 Stability of Vicinal Surfaces: Continuum Approach.- 5. Layer-By-Layer Growth and Growth Manipulation.- 5.1 Basic Concepts.- 5.2 Layer-By-Layer Growth by Surfactants.- 5.3 Layer-By-Layer Growth Through Growth Manipulation.- 5.4 Layer-By-Layer Growth Through Surface Reconstruction.- 5.5 Theory of Pulsed Deposition.- 5.6 Kinetic Roughening and Layer-By-Layer Growth.- 6. Methods.- 6.1 Deposition and Vacuum.- 6.2 Microscopy.- 6.2.1 Scanning Tunneling Microscopy.- 6.2.2 Field Ion Microscopy.- 6.3 Diffraction.- 6.4 Total Energy Calculations.- 6.4.1 Density Functional Theory.- 6.4.2 Semi-Empirical Many Body Potentials.- 6.5 Growth Simulations.- 6.5.1 Molecular Dynamics.- 6.5.2 The Kinetic Monte Carlo Method.- 6.5.3 Constructing KMC Models.- 6.5.4 Hybrid Approaches.- References tb.