Fundamentals for Plasmas and Processes

Chair: Prof. M. Shiratani

Lecturer: Dr. Andre Anders
Lawrence Berkeley National Laboratory, USA Click to see the profile

Title: Fundamental of plasma discharge and plasma sources

In this introductory part of the short course, plasma is defined and basic plasma properties and parameters are introduced, such as the Debye length and the electron and ion plasma frequencies. Next, the plasma boundary layer, or sheath, is described as a region of critical importance to all plasma processing, including plasma-assisted deposition and etching. Various discharge types are used to produce plasmas, ranging from glow and arc discharges to radio-frequency (RF) and microwave discharges. In all cases, elastic and inelastic collisions of electrons are key to plasma generation, and therefore we consider collision cross sections and mean free path concepts, illustrated by a device called the magnetron. Building on plasma sources, ion extraction is explained leading to a clear understanding of plasma versus ion sources.

Lecturer: Prof. Hiroshi Akatsuka
Tokyo Institute of Technology, Japan Click to see the profile

Title: Plasma Diagnostics using Optical Emission Spectroscopy

Optical Emission Spectroscopic (OES) Measurement is one of the most ideal plasma measurement methods, since it does not perturb the plasma. We would like to review various methods of OES measurement for processing plasmas in this tutorial course. First, we compare a couple of methods to diagnose processing plasmas with low-electron temperature and density, such as probe method, laser method, and OES method, and understand pros and cons of OES measurement. Then, we overview elementary processes to describe excitation kinetics in low-temperature plasmas. Next, we introduce collisional radiative (CR) model to describe number density of excited states based on the elementary processes. A method is presented to obtain electron temperature and density of plasmas based on the CR model. Next, we introduce a method to determine rotational and vibrational temperatures of electronically excited species of diatomic molecules like N2 or OH radicals in molecular gas-discharge plasmas. The rotational temperature could be useful to monitor an approximate value to the gas temperature of plasma in a state of non-equilibrium. Finally, we describe actinometry method that determines number density of atomic species, such as H, N and O, generated by dissociation reaction in molecular gas-discharge plasmas.

Lecturer: Prof. Holger Kersten
Kiel University, Germany Click to see the profile

Title: Basic aspects of dusty plasmas: generation, diagnostics and application

Powder formation, modification and trapping in gas discharges have received growing interest during the last decades. The unique possibility of dust particle confinement and control in the gas phase makes complex plasmas to excellent media for particle handling and treatment. The applications for processing of powder particles in plasma are numerous, most of them emerging in modern material science [1].
The main sources of particle generation during plasma surface processing and the formation of nano-composite materials are (i) the formation of large molecules, mesoscopic clusters and particles in the plasma bulk by chemically reactive gases, and (ii) the formation and incorporation of particles at surfaces (target, substrate) by means of plasma-wall interaction. The plasma process promotes the particle formation by excitation, dissociation and reaction of the involved species in the gas phase. Typical examples are plasma polymerization and thin film deposition in silane-containing plasma enhanced chemical vapor deposition (PECVD) processes. The different stages of the particle growth in the gas phase can be observed by various plasma diagnostics as mass spectrometry, laser induced evaporation, photo-detachment, IR absorption, microwave cavity measurements, Mie scattering and self-excited electron resonance spectroscopy (SEERS). Common diagnostics of particle formation also use the observation and analysis of harmonics and other discharge characteristics [2, 3]. In addition to well-established plasma diagnostic methods we perform also examples of "non-conventional" low-cost diagnostics which are applicable in technological plasma processes.
On the other hand, the interaction between microscopic (probe) particles and the surrounding plasma can be used for diagnostic purposes of the complex plasma itself, e.g. by observing position and motion of the particles in dependence on the discharge parameters. For example, information on the electric field in front of electrodes and on the energy fluxes in the plasma can be obtained.

REFERENCES:

[1] H. Kersten, M. Wolter, "Complex (dusty) plasmas: Application in material processing and tools for plasma diagnostics", in: "Introduction to complex plasmas" (ed. By M. Bonitz et.al.), Springer 2010, 395-442.

[2] A. Hinz, E. Wahl, F. Faupel, T. Strunskus, H. Kersten, J. Phys. D: Appl. Phys. 48(2015) 055203.

[3] J.C. Schauer, S. Hong, J. Winter, Plasma Sources Sci. Technol. 13(2004), 636.

HiPIMS - Principle and Industrial Application

Chair: Prof. Y. Setsuhara

Lecturer : Ralf Bandorf
Fraunhofer-IST Braunschweig, Germany Click to see the profile

Lecturer: Prof. Arutiun Ehiasarian
Sheffield Hallam University, UK

Plasma Skin Rejuvenation and Dermatology

Chair : Prof. Holger Kersten Click to see the profile

Lecturers : Prof. Hans-Robert Mentelman, MD Click to see the profile

Lecturers : Prof. Dr. Thomas von Woedke Click to see the profile

• University Medicine Greifswald, Greifswald, Germany
• Leibniz Institute for Plasma Science and Technology (INP Greifswald), Greifswald, Germany
• National Center for Plasma Medicine (NZPM), Berlin, Germany

Aesthetic Plasma Medicine – Key Points and First Results of a Clinical Study Program in Aesthetic Medicine applying Physical Plasma.