The short courses will take place on Sunday, June 4, 2017 and will consist of the following:
- Short course A: “Nucleation and growth of self-assembled nanostructures: Materials science of small things: self-assembly and self-organization” given by Joe E. Greene, University of Illinois at Urbana-Champaign, Urbana, IL, USA;
- Short course B: “Ionized physical vapor deposition and related technologies” given by André Anders, Lawrence Berkeley National Laboratory, Berkeley, CA, USA;
- Short course C: “Fundamental aspects of reactive magnetron sputtering” given by Diederik Depla, University of Ghent, Ghent, Belgium.
Short course A: “Nucleation and growth of self-assembled nanostructures: Materials science of small things: self-assembly and self-organization”
Instructor: Joe Greene, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Understand the primary experimental variables and surface reaction paths controlling nucleation/growth kinetics and microstructural evolution during vapor-phase deposition.
- Learn about the primary classical and quantum effects which controllably alter the properties of increasingly small nanostructures.
- Understand the mechanisms controlling self-assembly and self-organization during nanostructure growth.
- Learn how to better design nanostructure growth processes.
The study of nanotechnology is pervasive across widespread areas including microelectronics, optics, magnetics, hard and corrosion resistant coatings, mechanics, etc. Progress in each of these fields depends upon the ability to selectively and controllably deposit nanoscale structures with specified physical properties. This, in turn, requires control — often at the atomic level — of nanostructure, nanochemistry, and cluster nano-organization.
Decreasing size scales of solid clusters can result in dramatic property changes due to both “classical” effects associated with changes in average bond coordination and, as cluster sizes become of the order of the spatial extent of electron wavefunctions, quantum mechanical effects. The course will start with examples including reduced melting points, higher vapor pressures, increased optical bandgaps, decreased magnetic hysteresis, and enhanced mechanical hardness. Essential fundamental aspects, as well as the technology, of nanostructure formation and growth from the vapor phase will be discussed and highlighted with “real” examples using insights obtained from both in-situ and post-deposition analyses.
Nanostructure case studies include:
- examples of template, size, and coarsening effects: self-assembled Si/Si(001), Cu/Cu(001),TiN/TiN(001), TiN/TiN(111) nano-clusters,
- examples of controlled template plus strain effects: self-organized Ge wires on Si(111), Ge wires on Si(187 72 81), Au chains on Si(553), InAs metal wires on GaAs(001), insulated metal wires on Si(111),
- quantum dot engineering: formation, shape transformations, and ordering in self-organized SiGe/Si(001); InAs/GaAs(001), CdSe/ZnSe(001), PbSe/PbEuSe(111), Ag/Pt(111), and MnN/Cu(001) quantum dots,
- nano-catalysis: Au/TiO2, and
- examples of 3D nanostructures: (Ti,Ce)N/SiO2, TiBx/SiO2, and d-TaN/g-Ta2N/SiO2.
The course provides an understanding of:
- the classical and quantum effects controlling the dramatic property changes observed in nanostructures as a function of cluster size and dimension (3D → 2D → 1D)
- self-assembly and self-organization during film growth
- nucleation and growth modes
- the role of the substrate template and defect structures in mediating growth kinetics
- the development, and control, of film stress (strain engineering)
- the use of film stress to controllably manipulate nanostructure
- other mechanisms (including surface segregation, surfactant effects, low-energy ion bombardment, cluster coarsening, etc.) for controlling nanostructures
- the design of nanostructures with specified properties.
Short course B: “Ionized physical vapor deposition and related technologies”
Instructor: André Anders, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
This course is intended for students, engineers, technicians, and others interested in plasma-assisted deposition of thin film and functional coatings. A good portion of the course is dedicated to introduce and review the basics of low-temperature plasmas and discharges to produce them. While gas plasmas are often used, emphasis is put on discharges that lead to ionization of condensable metal or metal-containing plasmas vapor, arc, and sputtering sources. In contrast to many other courses, the role of plasmas and sheaths will be clearly distinguished and explained. This distinction will be appreciated when examples of processes with plasmas are given, including but not limited to plasmas made by ion plating, filtered cathodic arcs and by high power impulse magnetron sputtering (HiPIMS). HiPIMS has become a much-researched field in the last years because it emerged as an extension of widely used sputtering technology. With sputtered metals ionized the texture of coatings can be tuned by energetic condensation even when substrates are kept near room temperature. Recent developments of HiPIMS will be discussed, including reactive HiPIMS and so-called “hybrid technology” where one of the components is HiPIMS.
Short course C: “Fundamental aspects of reactive magnetron sputtering”
Instructor: Diederik Depla, University of Ghent, Ghent, Belgium
Reactive magnetron sputter deposition is a mature technique often used in laboratories and at industrial level to grow compound thin films. The growth of these films is defined by the deposition conditions, and therefore a good knowledge of the deposition process is essential to tune the growth as well as the film properties. After a short introduction on the physics of sputtering, the magnetron discharge and the transport of sputtered atoms through the gas phase, the course starts with a few definitions regarding reactive sputtering to show that the processes driving this technique are generally applicable. This introduction will assist the attendee toward the next step: the description of the most common experiment during reactive magnetron sputtering – the hysteresis experiment. The simplicity of this experiment fools initially the scientist because it hides a complex interplay between different processes at the target, in the plasma and at the substrate. During the course the details of this experiment are analyzed, and modeling is used to introduce different processes. In this way, the attendee will gain knowledge of the wealth of important processes controlling thin film growth such as reactive ion implantation, chemisorption, preferential sputtering, deposition profile, discharge voltage behavior etc. A good knowledge of these processes will help the attendee to analyze and to control the reactive sputtering process.
Chapter 1 – Sputter deposition; Sputtering – ion solid interaction, sputter yield; Secondary electron emission; The magnetron discharge;
Chapter 2 – Definitions
Chapter 3 – A first experiment; Key aspects of reactive magnetron sputtering; Target poisoning;
Chapter 4 – A first model; The Berg model – gas balance equations; Feedback control; Process stability;
Chapter 5 – Important process parameters; The discharge power; The deposition profile – influence of the deposition geometry; The magnetic field – the racetrack;
Chapter 6 – More complex conditions; Dual reactive sputtering – two sources, one reactive gas;
Mixed reactive gasses – oxynitrides; Reactive sputtering from an alloy target;
Chapter 7 – Dynamics of reactive sputtering; Feedback control again; Gas pulsing;
Chapter 8 – A second series of experiments; Target sputter cleaning – balance between oxide formation and removal; Influence of the argon pressure; Influence of the pumping speed;
Chapter 9 – Improving the model; Ion beam experiments; Reactive ion implantation; Knock on implantation; Fitting an experiment; New questions and some answers;
Chapter 10 – Discharge voltage behavior during reactive sputtering; Secondary electron emission – relationship between electronic properties and electron emission; Preferential sputtering; Predicting the discharge voltage behavior during reactive sputtering; Negative ion emission – origin, and influence on the thin film properties;
Chapter 11 – Influence of redeposit ion on the target – rotating cylindrical magnetrons; Rotating cylindrical magnetrons; Influence of the rotating speed on the hysteresis;
Chapter 12 – The influence of the deposition regime on the thin film growth; Structure zone models – origin and correlation with the deposition parameters; Energy flux measurements – the concept of the available energy per arriving atom.