- Superfici ed Interfacce
- Introduzione
Syllabus del corso
Obiettivi
Il corso ha due obiettivi. Da un lato, completare le conoscenze acquisite durante il corso di Fisica dello stato solido, rispondendo alla domanda fondamentale: cosa succede alle proprietà di un solido perfetto ed infinito quando la periodicità del reticolo cristallino finisce ad una superficie? D'altro canto, intende fornire le basi per tutte le applicazioni della fisica dei semiconduttori, della fisica dei dispositivi elettronici e delle nanotecnologie, che coinvolgono inevitabilmente superfici, interfacce e deposizioni epitassiali. L'approccio è sia teorico che sperimentale
Contenuti sintetici
I fenomeni di adsorbimento, di diffusione e di desorbimento di atomi e molecole ad una superficie in 6 Lezioni.
La deposizione epitassiale di film sottili su di un substrato, tecniche e modelli, in 7 Lezioni.
La formazione di interfacce e l'allineamento delle bande elettroniche nei due materiali, come base dei dispositivi elettronici, in 5 Lezioni.
Il Corso si chiude con 4 Lezioni di temi avanzati, riguardanti la epitassia tridimensionale di quantum dots e nanowires.
Programma esteso
Lesson 1: Introduction to Surface Science and to the Course
Lesson 2: Ultra High Vacuum and the preparation of clean surfaces
Lesson 3: Experimental methods for the analysis of surface composition
Lesson 4: Surface Bravais lattices and 2-dimensional reciprocal lattices
Lesson 5: The LEED scattering technique for surface structure
Lesson 6: The ion scattering technique for surface composition and structure
Lesson 7: Structural analysis by Rutheford Back Scattering (RBS) techniques
Lesson 8: Microscopy at the atomic resolution, FIM and scanning probes (STM)
Lesson 9: The electronic charge density at metal surfaces
Lesson 10: Shockley surface states at metal gaps
Lesson 11: The tight binding approach to surface states and the local DOS
Lesson 12: The angle-resolved photoemission spectroscopy for band dispersion
Lesson 13: The electronic bands at notable metal surfaces
Lesson 14: The hybrid-orbital approach to the electronic states in semiconductors
Lesson 15: Surface states in tetrahedral semiconductors for the «as cut» configuration
Lesson 16: The intriguing reconstructions of the Si (111) surface
Lesson 17: Dimer-pair reconstructions at Si (100), Si (110), and GaAs (110) surfaces
Lesson 18: Charge transfer and reconstructions at polar semiconductor surfaces
Lesson 19: Thermodynamics at surfaces, the surface energy and the surface tension
Lesson 20: Surface energies of different facets and the equilibrium morphology of crystals
Lesson 21: The larger mean square displacement for vibrations at the surface (theory)
Lesson 22: LEED intensities for the mean square displacement and the surface melting
Lesson 23: Surface vibrations in the elastic medium and in the diatomic chain
Lesson 24: Kinematics of the inelastic scattering at surfaces and the EELS technique
Lesson 25: Measurement of phonon dispersion relations by inelastic He scattering
Lesson 26: Theory and measurements of surface phonon dispersions for notable cases
Lesson 27: The physisorption of atoms and molecules at metal surfaces
Lesson 28: The chemisorption and the dissociative adsorption at surfaces
Lesson 29: Surface diffusion of adsorbate species
Lesson 30: Two-dimensional phase transitions in adsorbate layers
Lesson 31: Adsorption and desorption kinetics in a microscopic picture
Lesson 32: Adsorption kinetics in and out of equilibrium, elements of deposition
Lesson 33: Deposition techniques: evaporation and Molecular Beam Epitaxy
Lesson 34: Deposition techniques: epitaxy by means of chemical reactions
Lesson 35: Modalities of film growth and the AES signal with deposition
Lesson 36: The capillarity model of 2- and 3-dimensional island nucleation
Lesson 37: Recalls of dislocation formation energy and the thermal misfit
Lesson 38: Critical thickness for plastic relaxation in heteroepitaxial films
Lesson 39: Film-growth studies: experimental methods and some notable results
Lesson 40: Structural models of solid/solid interfaces and the notable Si/SiO2 interface
Lesson 41: Principles governing the electronic structure of solid/solid interfaces
Lesson 42: Metal induced gap states at a metal/semiconductor interface
Lesson 43: Virtual induced gap states at a semiconductor heterointerface
Lesson 44: The Schottky barrier and the modulation-doped heterojunction
Lesson 45: Rate equation models for kinetics and thermodynamics of epitaxy (Adv.)
Lesson 46: Thermodynamics of epitaxial quantum dots, morphology versus size (Adv.)
Lesson 47: Oswald ripening of quantum dots and the role of substrate patterning (Adv.)
Lesson 48: Kinetics and thermodynamics in the epitaxy of nanowires and fins (Adv.)
Prerequisiti
Corso avanzato in Fisica dello Stato Solido
Modalità didattica
Lezioni Frontali. Per questo anno accademico 2020/2021, a causa delle disposizioni relative alla emergenza Covid 19, le lezioni potrebbero essere tenute in modalità remota asincrona, cioè caricate sulla piattaforma e-learning. In tal caso, sono previste riunioni periodiche con gli studenti, in modalità sincrona tramite Webex, in modo da discutere dubbi e problemi sollevati dagli studenti stessi. Le modalità di erogazione delle lezioni, saranno soggette alle disposizioni dell'ateneo per la didattica del secondo semestre 2020/2021.
Materiale didattico
TESTO PRINCIPALE
H. Luth, Solid Surfaces, Interfaces and Thin Films, Sixth Edition, Springer Verlag, 2015;
TESTI AUSILIARI (tutto il materiale strettamente necessario è caricato sulla piattaforma e-learning)
A. Zangwill, Physics at Surfaces, Cambridge 1990;
M. C. Desjonquères and D. Despanjaard, Concepts in Surface Physics, Springer Verlag, 1998;
J.E. Ayres, Heteroepitaxy of Semiconductors, CRC Press, 2007;
M. Prutton, Introduction to Surface Physics, Oxford Un. Press, 1994;
J.A. Venables, Introduction to Surface and Thin Film Processes, Cambridge Un.Press, 2000;
J.B. Hudson Surface Science, Wiley Interscience Publications, 1998.
Periodo di erogazione dell'insegnamento
Secondo semestre
Modalità di verifica del profitto e valutazione
Esame orale, consistente in due o tre domande su parti diverse del corso, in cui viene richiesto di appoggiare la propria illustrazione dell'argomento con grafici, equazioni, o dati numerici del caso. Il voto assegnato e' espresso in trentesimi. Nel caso le disposizioni di ateneo per l'emergenza Covid 19 lo richiedano, l'esame sarà svolto in modalità remota sincrona, tramite Webex.
Orario di ricevimento
Per appuntamento tramite richiesta e-mail a leo.miglio@unimib.it. Sarà possibile incontrarsi anche in via remota, tramite Webex meeting.
Aims
The course has two targets. On the one hand, to
complete the knowledge acquired during a Course in Solid State Physics,
answering the fundamental question: what happens to the properties of a perfect
and infinite solid when the lattice periodicity ends at a surface? On the other
hand, it is intended to provide the basis for all applications of Semiconductor
Physics, Physics of Electronic Devices and Nanotechnologies, inevitably
involving surfaces, interfaces and epitaxial depositions. The approach is both
theoretical and experimental.
Contents
The science of free surfaces in 26 Lessons: experimental techniques and theoretical models for the study of composition, structure, electronic states, thermodynamics, and vibrational properties.
The phenomena of adsorption, diffusion and desorption of atoms and molecules on a free surface, in 6 Lessons.
The epitaxial deposition of a thin film on a substrate, techniques and models in 7 Lessons.
The structures of interfaces and the alignment of the electronic bands in the two materials, as the basis of electronic devices, in 5 Lessons.
The course ends with 4 Lessons of advanced surface topics, concerning the three-dimensional epitaxy of quantum dots and nanowires.
Detailed program
Lesson 1: Introduction to Surface Science and to the Course
Lesson 2: Ultra High Vacuum and the preparation of clean surfaces
Lesson 3: Experimental methods for the analysis of surface composition
Lesson 4: Surface Bravais lattices and 2-dimensional reciprocal lattices
Lesson 5: The LEED scattering technique for surface structure
Lesson 6: The ion scattering technique for surface composition and structure
Lesson 7: Structural analysis by Rutheford Back Scattering (RBS) techniques
Lesson 8: Microscopy at the atomic resolution, FIM and scanning probes (STM)
Lesson 9: The electronic charge density at metal surfaces
Lesson 10: Shockley surface states at metal gaps
Lesson 11: The tight binding approach to surface states and the local DOS
Lesson 12: The angle-resolved photoemission spectroscopy for band dispersion
Lesson 13: The electronic bands at notable metal surfaces
Lesson 14: The hybrid-orbital approach to the electronic states in semiconductors
Lesson 15: Surface states in tetrahedral semiconductors for the «as cut» configuration
Lesson 16: The intriguing reconstructions of the Si (111) surface
Lesson 17: Dimer-pair reconstructions at Si (100), Si (110), and GaAs (110) surfaces
Lesson 18: Charge transfer and reconstructions at polar semiconductor surfaces
Lesson 19: Thermodynamics at surfaces, the surface energy and the surface tension
Lesson 20: Surface energies of different facets and the equilibrium morphology of crystals
Lesson 21: The larger mean square displacement for vibrations at the surface (theory)
Lesson 22: LEED intensities for the mean square displacement and the surface melting
Lesson 23: Surface vibrations in the elastic medium and in the diatomic chain
Lesson 24: Kinematics of the inelastic scattering at surfaces and the EELS technique
Lesson 25: Measurement of phonon dispersion relations by inelastic He scattering
Lesson 26: Theory and measurements of surface phonon dispersions for notable cases
Lesson 27: The physisorption of atoms and molecules at metal surfaces
Lesson 28: The chemisorption and the dissociative adsorption at surfaces
Lesson 29: Surface diffusion of adsorbate species
Lesson 30: Two-dimensional phase transitions in adsorbate layers
Lesson 31: Adsorption and desorption kinetics in a microscopic picture
Lesson 32: Adsorption kinetics in and out of equilibrium, elements of deposition
Lesson 33: Deposition techniques: evaporation and Molecular Beam Epitaxy
Lesson 34: Deposition techniques: epitaxy by means of chemical reactions
Lesson 35: Modalities of film growth and the AES signal with deposition
Lesson 36: The capillarity model of 2- and 3-dimensional island nucleation
Lesson 37: Recalls of dislocation formation energy and the thermal misfit
Lesson 38: Critical thickness for plastic relaxation in heteroepitaxial films
Lesson 39: Film-growth studies: experimental methods and some notable results
Lesson 40: Structural models of solid/solid interfaces and the notable Si/SiO2 interface
Lesson 41: Principles governing the electronic structure of solid/solid interfaces
Lesson 42: Metal induced gap states at a metal/semiconductor interface
Lesson 43: Virtual induced gap states at a semiconductor heterointerface
Lesson 44: The Schottky barrier and the modulation-doped heterojunction
Lesson 45: Rate equation models for kinetics and thermodynamics of epitaxy (Adv.)
Lesson 46: Thermodynamics of epitaxial quantum dots, morphology versus size (Adv.)
Lesson 47: Oswald ripening of quantum dots and the role of substrate patterning (Adv.)
Lesson 48: Kinetics and thermodynamics in the epitaxy of nanowires and fins (Adv.)
Prerequisites
Advanced Course in Solid State Physics
Teaching form
Frontal lessons. For this 2020/2021 academic year, due to the provisions related to the Covid 19 emergency, the lessons could be held remotely in asynchronous modality, that is uploaded in the e-learning platform. In this case, periodic meetings will be organized with the students, synchronously via Webex, in order to discuss doubts and problems raised by the students. The modality for the delivery of the lessons will be subject to the provisions of the university for the teaching in the second semester 2020/2021.
Textbook and teaching resource
MAIN TEXT
H. Luth, Solid Surfaces.., Sixth Edition, Springer Verlag, 2015;
ADDITIONAL TEXTS (all the material which is strictly necessary is uploaded in the e-learning platform)
A. Zangwill, Physics at Surfaces, Cambridge 1990;
M. C. Desjonquères and D. Despanjaard, Concepts in Surface Physics, Springer Verlag, 1998;
J.E. Ayres, Heteroepitaxy of Semiconductors, CRC Press, 2007;
M. Prutton, Introduction to Surface Physics, Oxford Un. Press, 1994;
J.A. Venables, Introduction to Surface and Thin Film Processes, Cambridge Un.Press, 2000;
J.B. Hudson Surface Science, Wiley Interscience Publications, 1998.
Semester
Second semester
Assessment method
Oral examination, consisting in two, or three questions on different parts of the course, where the illustration of the topic is requested to be accompanied by sketches, equations, or numerical data, depending on the case. The final mark is given di a numerical scale, from 18 to 30 cum laude. In case the provisions of the university for the Covid 19 emergency will require a remote examination, it will be held in synchronous modality, via the Webex platform.
Office hours
By appointment after e-mail request to leo.miglio@unimib.it. It will be possible also to have a remote colloquium via the Webex meeting tool.