Investigation on HVPE of non-and semipolar GaN

The PolarCoN project P01 aims to investigate the epitaxial growth of high quality thick non- and semipolar GaN layers which then can be used as substrates for a subsequent heterostructure deposition. To this end, we will combine the high flexibility of metalorganic vapor phase epitaxy (MOVPE) for the optimization and defect reduction in such layers with the high growth rate of hydride vapor phase epitaxy (HVPE). In the first phase of the project, we have developed a method which allows to achieve semipolar planar surfaces by making use of the c-plane growth direction. This is done by etching grooves with c-plane like side walls into sapphire wafers of specific orientations from which the subsequent epitaxial growth starts. In the second phase, we will optimize this method in particular for the (10-11) plane of GaN grown on (11-23) (n-plane) sapphire wafers. Additionally, we will investigate whether this procedure is also applicable to other semipolar surfaces like, e.g. the (20-21) surface. Subsequently, these layers will be overgrown by HVPE to achieve several hundred μm thick layers, which eventually can be separated from the sapphire substrates to get free-standing semipolar GaN wafers. The close collaboration with the partners of our research group will help to understand the microstructure of such layers and eventually reduce the crystalline defects typically involved in such non-c-plane growth procedures. 

Project Leader


  • Ferdinand Scholz
  • Institut für Optoelektronik
  • Albert-Einstein-Allee 45
  • 89081 Ulm
  • Tel.: +49 (0)731/50-26052
  • Fax: +49 (0)731/50-26049