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7236 |
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Yttria coatings for wear protection in the semiconductor industry |
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Martin Nicolaus / Leibniz University Hannover, Germany Hans Jürgen Maier / Leibniz Universität Hannover, Institute of Materials Science, Mareike Benedde/ Leibniz Universität Hannover, Institute of Materials Science, Ralf Walther/ CE-Mat GmbH, Kai Möhwald/ Leibniz Universität Hannover, Institute of Materials Science, |
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In the semiconductor industry, wafers made of single crystal silicon but also those of special materials such as GaN or SiC are processed in plasma etching systems under thermally, electrically and chemically aggressive conditions. Chamber parts that are located in the plasma etching system are also exposed to these conditions. These components are usually made of anodized aluminum alloys, quartz or high-performance ceramics. As a result, they are electrically insulating and relatively well protected against chemical and physical attacks in the plasma etching processes. Additionally parts located near the process area are coated with yttria to increase service life and thus process performance. These yttria coatings are porous and can be attacked by fluorine containing plasma. In order to increase the lifetime of the components in the plasma etching system, this research project aims to optimize the protective yttria layer by minimizing the porosity of the protective layer. For this purpose, a design of experiment was established in which the porosity is the target value. The main effects of the coating parameters and their interactions including the surface treatment before the coating process were determined. Furthermore, the bonding of the protective coating to the component to be protected, as well as the element distribution and the coating morphology were investigated by instrumental analysis. The results and their ramifications with respect to the envisaged application will be discussed. |