Short Course Level: Intermediate
Sputtering has become one of the most important technologies not only for large area applications, but also for optical technologies. With magnetron sputtering, a large variety of products in different applications are produced, beginning from large area low-e coatings to ultra-precise filters with more than 1000 layers. Sometimes it is quite astonishing that extreme beautiful properties of magnetron-sputtered layers are obtained although the plasma is inherently instable.
Within the intermediate level course, people should become familiar with the different process concepts of magnetron sputtering, as used today for the development and production of optical coatings. The attendee will have a deeper understanding what happens in a (reactive) magnetron sputter process and how he can handle instabilities of the process, and how he can control uniformities, particle contamination or specific layer properties in the deposition process.
The general focus of the course is on deposition processes for optical coatings and their connection of the plasma properties to the relevant film properties such as roughness, density, optical losses etc.
An overview is given to the process modifications which currently are undertaken to optimize layer properties such as: high or low roughness, hardness, elasticity, deposition temperature, deposition rate, stress, optical absorption and so on. Moreover, some recent findings about the occurrence of particles will be presented. The course addresses not only coatings on flat substrates, but also coatings on 3D components, e.g. for the use with broadband AR coatings on lenses.
First, a short introduction into the physics of sputtering, the magnetron discharge and the transport of particles through the gas phase will be given. After the introduction of the magnetron cathode for sputtering in the second step, the focus will be on reactive magnetron sputtering. The effect of the hysteresis in a reactive sputter process, which comes into play, will be discussed along with the common approaches to overcome the hysteresis. Pulsed magnetron sputter techniques (including HIPIMS) and cathode concepts (planar, rotatable) will be discussed, also with regard to differences in the ion energy distribution function. As a sidestep, the method of plasma simulation by Particle in Cell Monte Carlo Simulations is presented, allowing to calculate ion energy distributions functions and to design improved magnetron systems.
The second part is more application oriented and concentrates on application oriented film properties obtained by reactive magnetron sputtering. Examples of present and arising applications will be given, e.g. process concepts for precise multilayers, sputtering with rotatables, a-Si:H sputtering, passive and active large area coatings, scratch resistant coatings on glass/sapphire, deposition on plastic substrates.
Short Course Benefits and Learning Objectives: This course should enable you to:
- Compare different deposition process concepts of (reactive) magnetron sputtering;
- Determine how hysteresis effects in reactive processes occur and how they can be handled;
- Understand what effects may influence uniformity;
- Explain differences of process control concepts;
- Discover dependencies of materials properties with process characteristics; and
- Identify different applications of magnetron sputtering for optical applications.