Carsten Hartmann
Senior Scientist
Leibniz-Institut für Kristallzüchtung (IKZ)
Carsten Hartmann studied materials science in Jena (Thuringia, Germany) and completed his doctorate at the Leibniz-Institut für Kristallzüchtung (IKZ) in collaboration with the BTU Cottbus on the topic of “Aluminum nitride volume crystal growth using physical gas phase transport” in 2013. He subsequently remained at the IKZ as a postdoc and senior scientist. As part of priority consortia of the Federal Ministry of Education and Research, particularly ”Advanced UV for Life”, he developed a superior bulk AlN crystal growth process that is now on the way to commercialization.
Presentations
Efficient Diameter Enlargement of Bulk AlN
Bulk AlN substrates with high structural quality are best suited to exploit the full potential of AlGaN-based (opto)electronic devices. However, further development and commercialization is hindered by the lacking availability of high quality AlN substrates in terms of quantity and size. So far, the diameter expansion has been limited by the low lateral growth rates or the formation of defects. In this paper, we report on a fast increase of the crystal diameters by subsequent growth runs with huge expansion angles of about 45°. The high structural quality of the first seed generation can be preserved (dislocation density TDD ~ 103cm-2). First epi ready 2-inch AlN substrates are demonstrated. The process outlines a shortcut path to industrially relevant AlN crystal diameters of 100 mm or more compared to all other published expansion processes for bulk AlN crystals so far.