Entwicklung von mikromechanischen Schaltern für neuartige MEMS-Produkte unter Aspekten industrieller Fertigungsprozesse

Abstract

The subject of this thesis is the development of new micromechanical switches as MEMS (Micro Electro Mechanical Systems) products for use in a variety of communication-applications.The research work performed within the frame of this thesis on the ´RF-switch´ (radio-frequency switch) is used to demonstrate the importance of an ´integrated design and development approach´ for a product-development. The successful realization, not only from a technological but also from an economic perspective, can only be achieved by considering all aspects of production for the entire end-to-end process, starting with the definition of the initial device-concept. Therefore an optimized integration of the front-end of line (FE-) processing and the back-end of line (BE-) processing together with the device packaging at the very end of the fabrication sequence has to be realized.The RF-switches are produced using a newly developed semiconductor process combination. First a poly-Si surface micromachining (SMM) process is used to create the mechanical switch-structure. Afterwards the special metal contacts are formed using additive electroplating technology (AET) in order to establish the electrically functional switch. The switch-element is then protected from the environment with a waferlevel-packaging scheme, before the individual device can be mounted into an SMD-package.The scientific focus of this thesis is marked by the device-concept for the RF-switch and the development of the end-to-end production process within the fab. The development of newly designed processing steps was required for this, which also included the challenging task of integrating these individual processing clusters and steps with each other within the production line. An analysis and characterization of the fabricated devices demonstrates the successful production capability. A discussion of the promising growth-potential for MEMS-products and RF-switches in particular is included in the appendix.