Microwave Plasma Sources -Applications in Industry

Plasma, excited with microwave energy, has very interesting properties which are in direct correlation with the excitation frequency. This is due to the reachable high electron density, which itself has an influence on the density of further generated particles like ions, radicals, excited atoms and molecules or UV light. Altogether they are responsible for the high chemical reactivity of microwave plasmas attaining their maximum in the pressure regime between 1 and a few hundred Pa. Therefore, comparatively low end pumping systems can be used to achieve good results in etching, activation and deposition processes. Together with the availability of microwave generators, grown with the market of microwave heating technology, microwave plasma is an interesting tool for industrial applications. Scalability of power up to 100 kW per single magnetron tube and lateral dimensions of a few square meters per single plasma source have opened the field to industrial thin film technology for typical large area applications as solar or other flat panel industries. Roth & Rau Muegge is utilizing these advantages to supply microwave generators and plasma technology for various fields of applications which will be provided as an overview to give insight into running activities in industry. Although the presented applications are part of publicly funded programs and projects together with partners from several research institutes and universities, the technical depth of this contribution has to consider running contracts and non disclosure agreements.