Fraunhofer Institute for Surface Engineering and Thin Films IST
Top view of the turntable of the EOSS® sputter system from above.
EOSS® – Production of optical coatings of the highest quality and with high throughput is no contradiction in terms
In many industrial applications such as photovoltaics, display technology, architectural and automotive glazing, fine optics, traffic, information and electrical engineering as well as aerospace, the coating of optical assemblies with the highest precision is the key to realizing required product properties such as reflection, transmission, polarization, scattering or color.
Deposition of optical interference filters
Interference filters for modern applications in the consumer sector as well as in special applications consist of highly complicated layer designs with different individual thicknesses. These must be deposited with both extreme precision and low defect rates. For the user, the stability of the process and the adjusted layer properties are also of great importance for productivity. This is largely determined by the uniformity of the coating thickness over the component, because this has a direct influence on the spectral characteristics which determine the function.
Innovative coating platform: The EOSS®-coating concept
The Fraunhofer IST uses magnetron sputtering technology for the production of optical coatings. In the EOSS®(Enhanced Optical Sputtering System), the substrates are arranged on a rapidly rotating turntable. Deposition takes place from the metallic or sub-stoichiometric rotating tube target and complete oxidation takes place using a plasma source. The high gas-chamber separation means that it is possible to achieve a permanently stable process without feedback control. Material properties are replicated just as reliably as the layer-thickness distribution over very long periods of weeks and months without readjustment. The productivity of the coating facilities of our customers can be enhanced through our MOCCA+® software, which not only allows optical in-situ monitoring, but can also adaptively control the coating process.
Industrial benefit
In consideration of the process chain and system properties of tools and components, we develop load-optimized surfaces for customer-specific applications. The EOSS® technology licensed to equipment manufacturers enables the production of new and extremely sophisticated optical coatings on an industrial scale with high process reliability. We also support you with our expertise and demo coatings – please do not hesitate to contact us!
Layer thickness distribution of SiO2 layers after various process steps.
Homogeneity of layers (fully loaded) after ten weeks of operation.
”With the EOSS®, we are able to realize many things that seemed impossible 10 years ago. Today, we are working on the further development of this innovative technology, where digitalization is playing an increasingly important role.”
Dipl.-Phys. Stefan Bruns, Project Manager