Cohesive Properties of Semiconductors under Laser Irradiation

Presentation on Reordering Processes in Laser Irradiated Semiconductors.- 1. Historical Introduction.- 2. General Mechanism of Laser Annealing.- 3. Examples.- 4. To be melted or not to be ?.- 5. Ionization Enhanced Annealing and Low Power Effects.- Lasers and Speckle Patterns.- 1. Interference Phenomenon and Coherence.- 2. Lasers.- 2.1 Spontaneous emission — Stimulated emission.- 2.2 Basic schema of a laser.- 2.3 Solid state lasers.- 2.4 Gas lasers.- 2.5 Semiconductor lasers.- 2.6 Organic dye lasers.- 3. Laser Speckle Patterns.- 3.1 Statistical study of a speckle pattern.- 3.1.1 First order statistics of a polarized speckle pattern.- 3.1.2 Second order statistics.- 3.2 Variation of a speckle pattern with a displacement of the object.- 3.2.1 Random intensity distribution generated by a laser-illuminated rough object.- 3.2.2 Variation of I(x,y) with a lateral translation of O.- 3.2.3 Variation of I(x,y) with an axial translation of O.- 3.2.4 Variation of I(x,y) with the inclination of the incident beam.- 3.2.5 Variation of I(x,y) with a change of the illuminating wavelength.- 3.3 Detection of in-plane deformation by speckle photography.- 4. Conclusions.- Pulsed Laser Irradiation of Semiconductors : Thermal Description.- 1. Introduction.- 2. Crystallization of Irradiated Layers.- 3. Thermal Description of Laser Irradiation.- 4. Dopant Incorporation.- 5. Conclusions.- Transport Theory.- 1. Introduction.- 2. The Generalized Kinetic Equations (Linear Case).- 3. From Kinetic Theory to Hydrodynamics.- 4. Remarks about the Dynamical Behavior of a System of Charged Particles.- Phase Diagrams and Segregation.- 1. Introduction.- 2. Phase Equilibria.- 3. Binary Liquid-Solid Phase Diagrams.- 3.1 Ideal solutions.- 3.2 Real solutions.- 3.2.1 Regular solutions with hxsRegular solutions with hxs>O.- 3.2.3 Other solution models.- 3.3 Invariant reactions.- 4. Ternary and Many Component Liquid-Solid Systems.- 5. Vapor-Liquid-Solid Phase Diagrams.- 5.1 Binary systems.- 5.2 Possible vapor transport in laser melting.- 6. Experimental Determinations of Phase Diagrams.- 7. Segregation Coefficients.- 7.1 Thermodynamic models.- 7.2 Experimental observations and their interpretations.- 8. Dynamics of Segregation.- 8.1 Observations in laser melting.- 8.2 Convective transport during laser annealing.- 9. Conclusions.- Statics and Dynamics of Phase Transitions : a Brief Introduction.- Theory of Crystal Growth.- 1. Introduction.- 2. Structure of Interfaces.- 2.1 Phenomenological models.- 2.2 Lattice models.- 2.3 Atomistic models.- 2.4 Interacting interfaces.- 3. Interface Kinetics.- 3.1 Lattice models.- 3.2 Phenomenological models.- 4. Transport Processes.- 4.1 Diffusion.- 4.2 Dynamic instabilities : flat surface, dendrites, eutectics.- 4.2.1 Flat surface instability.- 4.2.2 Dendrites.- 4.2.3 Eutectics.- 4.3 Hydrodynamic flow.- Dynamical Processes during Solidification.- Abstract.- 1. Introduction.- 2. Macroscopic Growth Rates.- 2.1 Free solidification.- 2.2 The rate of directional solidification.- 2.2.1 A sharp interface and a melt of non-interacting atoms.- 2.2.2 A diffuse interface and a melt of non-interacting atoms.- 2.2.3 A sharp interface and network melt.- 3. Entropy Fluctuations at the Solid-Liquid Interface.- 4. The Model.- 5. Conclusions.- Nucleation in Condensed Matter.- 1. Definition of the Nucleation and Growth Process.- 2. Homogeneous Nucleation at Constant Composition.- 2.1 Thermodynamics barrier of the critical cluster.- 2.2 Steady state rate of nucleation.- 3. Transient Nucleation.- 4. Heterogeneous Nucleation.- 4.1 Nucleation rate.- 4.2 Nucleation on dislocations.- 5. Boundary Energy and Transformation Strains.- 5.1 ?-? Interphase.- 5.2 Low angle grain boundary.- 6. Homogeneous Nucleation of Precipitate.- 7. Conclusion : Comparison with Experimental Results on Group IV Semiconductors.- Transient Bulk Induced Nucleation in Amorphous Group IV Semiconductors.- Abstract.- 1. Introduction.- 2. Review of the Theory of Transient and Steady State Bulk Nucleation.- 3. Experimental Results and Interpretation.- Crystalline, Amorphous and Liquid Silicon.- 1. Introduction.- 2. Instability of the Electron-Hole Plasma in Covalent Semiconductors.- 3. Kinetics of Crystallization of Amorphous Silicon.- Optical Properties of Semiconductors.- 1. Introduction.- 2. Basic Light-Matter Interaction.- 2.1 Optical spectra in the near band gap region.- 2.2 Optical spectra above the band gap.- 2.3 Collective electronic excitations in doped or optically excited semiconductors.- 2.3 Collective electronic excitations in doped or optically excited semiconductors.- 3. Polarization and Light Waves Coupled : the Polariton Approach.- 4. Probing Techniques.- 5. Nonlinear Effects.- 5.1 Gain spectra.- 5.2 Exciton spectra at high excitation densities.- 5.3 Plasma light scattering.- 5.4 Lattice heating.- 6. Summary.- Recombination Mechanisms in Semiconductors.- Abstract.- 1. Introduction.- 2. Radiative Recombination in Semiconductors.- 2.1 Band-to-band recombination.- 2.2 Free exciton recombination.- 2.3 Band-to-impurity transitions.- 2.4 Donor-acceptor pair transitions.- 2.5 Bound exciton recombination.- 3. Non-Radiative Auger Recombination.- 4. Conclusions.- Generation, Diffusion and Relaxation of Dense Plasmas in Semiconductors.- Abstract.- 1. Introduction.- 2. Experimental Techniques.- 3. Interband Saturation.- 3.1 Parametricmeasurements.- 4. Measurement of Nonlinear Carrier Diffusion.- 4.1 Moderate excitation levels.- 4.2 High excitation levels.- 5. Summary and Conclusions.- Transient Optical Properties of Laser-Excited Si.- Abstract.- 1 . Experimental.- 2. High Reflectivity Phase.- 3. Recrystallization Kinetics.- 4. Cooling Rate beyond 200 nsec.- 5. Summary.- Time-Resolved Raman Studies of Laser-Excited Semiconductors.- Abstract.- 1. Experiment.- 2. Theory.- 3. Time Reversal Invariance.- 4. Temperature Measurements.- 5. Raman Line Shift.- 6. Conclusions.- Ultrafast Phase Transitions in Silicon Induced by Picosecond Laser Interaction.- Plasma Annealing and Laser Sputtering; Role of the Frenkel Exciton.- Abstract.- 1. Introduction.- 2. Sputtering.- 3. Frenkel Excitons and the Zero-Crossing of the Dielectric Function.- 4. Life Time of Electronic Excitation.- 5. Conclusions.- Multi-Electron Defects in the Elemental Semiconductors.- Abstract.- 1. Introduction.- 1.1 Definition and some basic properties of dislocations.- 1.2 Dislocations in semiconductors.- 2. Simple Models for Dislocations in the Elemental Semiconductors.- 2.1 Energy spectra.- 2.2 Occupation statistics.- 3. Core Structure of Dislocations.- 3.1 Atomic arrangement.- 3.2 Bond arrangements.- 4. Many-Electron Defects.- 4.1 Vacancy in silicon.- 4.2 Dislocations in the elemental semiconductors.- 4.3 Dislocations, experimental results.- 4.4 Capture and emission processes at dislocations.- Optically Excited Defects.- 1. Introduction.- 2. Defect States.- 2.1 Fundamental states.- 2.2 Excited states.- 3. Optical Excitation and Decay.- 3.1 Optical excitation.- 3.2 Mechanisms of decay.- 3.2.1 Emission of phonons.- 3.2.2 Luminescence.- 3.2.3 Auger de-excitation.- 3.2.4 Metastable states.- 4. Atomic Diffusion.- 4.1 General.- 4.2 Excited defects.- 4.2.1 Diffusion during decay.- 4.2.2 Excited state diffusion.- 4.2.3 Amorphous to crystal transition of Si and Ge.- 4.3 Other effects.- 5. Concluding Remarks.- The Role of Ionized Defects in Ge and Si Crystallization.- Abstract.- 1. Introduction.- 2. Determination of Crystallization in a-Ge.- 2.1 Ionization-enhanced crystallization in a-Ge.- 2.2 Thermal crystallization of doped and un-doped a-Si.- 2.3 Cw laser induced crystallization.- 3. Model.- 3.1 Dangling bonds in the bulk.- 3.2 Diffusion of dangling bonds.- 3.3 The amorphous-crystalline interface.- 3.4 The microscopic mechanism at the a-c interface.- 3.5 Origin of the growth rate activation energy.- Interfaces under Laser Irradiation.- 1. Introduction.- 2. Experimental.- 3. Segregation and “Solute Trapping”.- 4. Interface Instability.- 5. Glass Formation.- 6. Modeling Ultra-Rapid Solidification.- Laser Induced Ohmic Conduction in Gallium Arsenide.- 1. Introduction.- 2. Theoretical Background and Experimental Technique.- 3. Laser Alloying of Au-Ge/GaAs Structures.- 4. Pulsed Beam Annealing of High Dose Implants in GaAs.- 5. Laser-Assisted Diffusion.- 6. Conclusion.- Synthesis of High Purity Semiconducting Compounds by Laser Irradiation.- 1. Introduction.- 2. General Experimental Conditions.- 2.1 Film preparation.- 2.2 Laser annealing.- 2.3 Identification.- 3. The Nature of the Transformation.- 3.1 Free-standing samples.- 3.2 Supported samples.- 3.3 Discussion.- 3.4 Conclusion.- 4. Characterization.- 4.1 Transmission electron microscopy.- 4.2 Electrical transport measurements.- 4.3 Optical absorption measurements.- 4.4 Photocurrent measurements.- 4.5 Conclusion.- 5. Final Comments.- Effects of Pulsed Laser Irradiation on the Electrical Properties of GaAs.- 1. Introduction.- 2. Properties of MetalSemiconductor Junctions.- 2.1 With shallow levels only.- 2.2 With shallow and deep levels.- 2.2.1 Trap occupation statistics.- 2.2.2 Capacitance Transients.- 2.2.3 Deep level transient spectroscopy (DLTS).- 3. Experimental Results.- 3.1 I(V) and C(V) measurements.- 3.2 DLTS measurements.- 4. Conclusion.- Laser Annealing of Semiconductors Studied by Mossbauer Spectroscopy.- 1. Introduction.- 2. The Method.- 3. Parameters Observable in Mössbauer Experiments.- 4. Mossbauer Probes.- 5. What can be learned from Mössbauer Spectroscopy.- 6. 57Fe Mössbauer Studies.- 7. 119Sn Mössbauer Studies.- 8. 125Te and 129I Mössbauer Studies.