Research

Prof. Dr. Bernhard Wagners group works in the field of Microelectromechanical systems (MEMS). This includes the investigation of new materials and process capabilities, fabrication of micro systems and experimental characterisation. In research this work is strongly linked to the work of the Fraunhofer institute for silicon technologies (Fraunhofer ISiT). 

The practical work is mainly carried out in the Kiel’s clean room (Nanolabor), which has been established in 2008. Most of the work here is on 6 inch wafer level. In order to ensure the best compatibility with the Fraunhofer ISIT, some additional tools at 200mm wafer level have been introduced to the nano-lab, such as atomic layer deposition (ALD), a bond aligner and a eutectic bonder, a 200mm electroplating tool, annealing equipment and a multi source sputtering tool. Both the Technical faculty and the Fraunhofer ISIT concentrate their activities in the competence center for nano system technologies.
Piezoelectric Micromechanical Systems (piezo-MEMS) have been one of the central research topics at the chair for Materials and Processes for Nanosystem Technologies since 2010 - especially the development of piezoelectric materials and thin film systems. Efforts to synthesize these materials are focused mainly on sputter deposition, while alternatives such as chemical solution deposition are investigated as well. Whereas initially our focus was on PZT and pure aluminum nitride, this has now shifted to solid solutions of AlN and ScN – a highly promising material due to its excellent energy efficiency and good technological compatibility. Efforts to increase the Sc content for better piezoelectric response and to control the mechanical stress of the films without adversely affecting the morphology of the films have proven successful and are an important basis for the integration of the material into the next generation of piezo-MEMS which currently takes place at Fraunhofer ISIT. Moreover, in 2018 they allowed the first observation of ferroelectricity in AlScN and thus in any of the III-V semiconductor based materials (Press release).
Current work focuses on extending the understanding of the unique ferroelectric properties of the wurtzite III-nitrides and on harnessing their potential in novel application concepts in both micromechanics and –electronics.
Another focus is the development of a generic fabrication technology for the integration of porous 3D microstructures into MEMS devices. To this end, powder agglomeration and subsequent solidification via custom ALD processes have been developed to provide a powerful and highly versatile  toolset to introduce e.g. volume micro-magnets to cleanroom technology.