The latest developments in the field of nano technology must not mislead to the impression that all challenges in the micro system technology (MST) are solved. As a matter of fact, right now new applications are causing novel technological challenges. In addition, the market of MST is still one of the most dynamic and will continue its growth within the next years. It is expected that the worldwide annual turnover will increase from 3.9 billion US$ (2002) to 8.3 billion US$ (2007) [1].