We perform specific research on the growth of silicon crystals by the Czochralski technique with respect to higher yield and improved material quality. For example we push the pull speed to its limit by optimization of the hot zone using numerical modeling or we unlock the secrets of the growth ridge in order to detect defect formation during crystal pulling. In the field of directional solidification emphasis is put on technology development and characterization of the Si ingots to be used for example as sputter targets or as mechanical components in the semiconductor industry.

© Fraunhofer IISB
Life time map of a mc Si ingot
© Kurt Fuchs / Fraunhofer IISB
Full wafer mapping of defects by XRT
© Fraunhofer IISB
Analysis of growth instabilities in heavily doped Si


  • Specific crystal growth experiments in special R&D furnaces in house and at partners’ sites
  • Investigation of melt – crucible interaction phenomena for Cz and DS configurations
  • Spray coating of crucibles, or furnace parts based on Si3N4, SiO2, SiC and TaC suspensions
  • Characterization:
    • shape of the solid-liquid interface by LPS
    • microstructural analysis of defect selectively etched samples
    • imaging of structural defects by X-ray topography
    • analysis of growth ridge geometry
    • determination of O, C, N by FTIR
    • minority carrier life time mappings (µPCD, MDP)
    • DLTS           
  • Simulation of heat and mass transport for Cz, FZ and DS including magnetic fields
© Anja Grabinger / Fraunhofer IISB
Silicon crystals are being grown in special R&D-furnaces.
© Fraunhofer IISB
Analysis of wetting behavior of silicon and other melts according to the sessile drop method.
© Fraunhofer THM
Analysis of physical, chemical, and electrical properties of silicon and other semiconductor materials.

Functional Coatings

Based on our expertise in the field of coatings, we are developing a novel technology for ultra-high-temperature-resistant protective coatings for space applications. The HOSSA project focusses on the application of ceramic protective coatings to fiber composites using powder coating technology. The goal is to bring the advantages of fiber composite components, such as high breaking elongation, high crack resistance, and high dynamic load capacity, to new applications by increasing heat and oxidation resistance as well as improved mechanical abrasion resistance. The patented technology offers a significant cost advantage over conventional coating processes and is also suitable for repairing components. HOSSA can be used to increase the efficiency of drives and the exposure time of re-entry vehicles. The protective coatings can also be used in aircraft and helicopter engines and gas turbines.

IISB insights: Functional Coatings in 90 Seconds


  • Customizable coating technology to achieve a variety of coating properties
  • Cost-effective technology with great flexibility in terms of size and geometry of the components to be protected
  • Allows use of fiber matrix composites in new applications
  • Higher combustion temperatures and therefore increased efficiency of rocket engines and boosters  

Focus Areas

Explore the areas of semiconductor crystal growth, epitaxy, and device processing including characterization and modeling.