Thin Film Technology

IMPT's thin-film technology division covers the design and manufacture of microsystems/MEMS (sensors, actuators). Most of our systems are based on electromagnetism.

Design

The initial system design is done by analytical and network-based methods. The detailed design is then carried out using FEM simulations. For this purpose, the multiphysics simulation tool ANSYS® is available, with which simulations e.g. in the fields of structural mechanics and electromagnetics as well as thermal and fluid dynamic simulations can be performed.

Actuators

The actuators manufactured at the IMPT use magnetic fields to generate movement. Depending on their operating principle, the actuators can be classified as synchronous, (variable) reluctance, and hybrid actuators. Both linear and rotating micromotors are manufactured, and the use of these magnetic microactuators is being investigated, e.g. in microoptics, the manipulation of magnetic nanoparticles and implantology.

Sensors

In addition to sensors based on electromagnetic principles, such as eddy current sensors, strain sensors, and GMR sensors (ultra-thin, for high-temperature applications), research at the IMPT focuses on modular sensors for gentelligent applications, including temperature sensors.

Manufacture

For the production of microactuators and sensors a combination of photolithography and electrodeposition is routinely used. Using photolithography, a temporary form of photoresist is created on Si or Al2O3 substrates and filled with functional materials by electrodeposition. As functional materials Cu is used for coils and leads. NiFe45/55, NiFe81/19, CoFe and Ni are used for flow guides. Furthermore, the epoxy resin SU-8™ and polyimide are used as embedding material and material for membranes. As insulation layers of Si3N4 and SiO2 are used, which are produced by PECVD (Plasma Enhanced Chemical Vapor Deposition). For patterning, ion beam etching and lift-off are also used. The production of mechanical components (membranes, bending beams, spring structures...) is done by a combination of photolithography and etching processes. For this purpose dry etching processes (e.g. DRIE, plasma) as well as wet chemical etching processes (e.g. KOH, HF) are available.


Technical Equipment

The institute has an ISO 5 clean room with various equipment for classical lithography processes, coating and etching methods as well as analytical equipment for characterization.