Magnetic sensors are gaining importance in various applications, such as autonomous driving, health care, and robotics, as they can measure essential properties without contact and free of wear. Scientists from the University of Bielefeld and Johannes Gutenberg University Mainz are developing integrated magnet sensors that yield a linear, hysteresis-free response to all three components of an external field. Furthermore, we want to substantially speed up the development process of such sensors.

To this end, the research lab „Mikroelektronik Bielefeld und Mainz für Magnetfeldsensorik“ combines theoretical modelling with modern thin film technologies with thickness accuracies far better than a single atomic layer and complex methods for determining sensor characteristics. For this purpose, comprehensive and complementary methods are used for the preparation of thin film systems, their characterization with respect to structural and magnetic properties, as well as for the investigation of the sensor properties.

In ForLab MagSens, we are developing novel, robust, and dedicated magnetic sensors for automatization/industry 4.0 and further application fields using modern concepts in material- and thin film research such as integrated computational materials engineering and machine learning. Our focus is on giant and tunneling magnetoresistance as sensor principles and the upscaling of research results to industry-compatible thin film deposition systems on 200 mm wafers.

Further information (partly in German) can be found on the following linked websites:

The Institute of Physics at Johannes Gutenberg University operates multiple deposition systems that enable the growth of epitaxial films on specific substrates as well as the deposition on standard wafers. The most capable deposition system is a Singulus Rotaris sputter machine. It allows for the installation of 18 different cathode materials and deposits homogeneously on wafers up to 200mm in size. Deposition can be done on heated substrates as well as in a magnetic field that can either homogenize magnetic properties or imprint a preferred magnetization direction during deposition. The thickness control of the layers is on the subangstrom scale and depositions are highly reproducible. Cosputtering of up to 4 cathodes is possible and dc and rf sputter modes enable the deposition of conducting and insulating layers. In addition to the standard argon gas flow channel, separate oxygen and nitrogen channels can be used for reactive sputtering. The 200mm wafers are loaded to a load lock chamber in a clean room environment and the deposition is performed fully automatically from cassette to cassette. Smaller wafers can be handled via carrier wafers.

The Institute of Physics at Johannes Gutenberg University operates a clean room with photolithography and electron beam lithography. We can pattern thin film nanostructures using either maskless projection UV-lithography (Durham Microwriter) or electron-beam lithography. The optical projection lithography is very versatile for feature sizes in micrometer range. The highest resolution below 100nm is achieved with 30kV e-beam lithography from Raith.

The Condensed Matter Division at the Institute of Physics is equipped with state-of-the-art equipment for materials characterization. All kinds of electrical transport measurements, from dc to rf, can be done from low to high temperatures and using high magnetic fields up to 17T. We employ a SQUID magnetometer and Kerr microscopy for magnetic characterization, and we use x-ray methods and scanning probe methods such as AFM and SEM for structural analysis. For a list of our capablilities, please see: