Silicon

We do applied research on the production of silicon for power electronics and photovoltaics application. In the field of power electronics, we pay special attention to the formation of dislocations and point defects during Czochralski growth of silicon crystals with extremely low and high electrical resistivity, during epitaxy, and further device processing steps together with our partners.

We support the development of the next generation Czochralski pullers and processes with respect to lower production costs, higher throughput and better material quality by experimental analysis and numerical simulation. Additionally, we develop and test innovative crucible and coating materials, new hot zone parts, alternative feedstock material, and explore the recycling of silicon waste.

We also perform fundamental studies of crystal growth phenomena by using microgravity conditions. Here our focus is the investigation of particle engulfment and the facet formation phenomena.

We carry out crystal growth experiments in special R&D furnaces in house and at partners’ sites. We are equipped with a sessile drop furnace, well suited to investigate melt – crucible interaction phenomena. Furthermore, we coat crucibles, substrates and other furnace components.

Our infrastructure includes a variety of characterization tools, including the possibility to measure the shape of the solid-liquid interface, the grain size and grain orientation of multicrystalline samples on full wafer scale, as well as a XRT tool (X-ray topography) for non-destructive, full wafer scale (up to 300mm) imaging of structural defects in substrates, epilayers and partially processed wafers.

To gain an in depth understanding of the heat and mass transport processes, including how to control the melt flow by magnetic fields, we intensively use numerical simulation and develop and apply techniques to measure in-situ temperatures and the position of the solid-liquid interface during crystal growth.