Prize for the best poster at the CS MANTECH conference goes to Ina Ostermay
On May 22, 2025, the poster by Dr. Ina Ostermay and further co-authors from the FBH (N. Thiele, A. Koyucuoglu, P. Paul, A. Bassal, A. Thies, F. Brunner, and O. Krüger) was presented with the Best Poster Award at the CS MANTECH conference in New Orleans (USA). The poster deals with a typical challenge in the activation of dotands in gallium nitride (GaN). In the specific example, silicon was used, which requires temperatures above 1250 °C – however, GaN decomposes at temperatures exceeding 850 °C. The FBH scientists therefore resorted to a ‘trick’ – so-called cap layers – which prevent the GaN surface from decomposing by forming a protective layer.
We have demonstrated that a combination of silicon nitride (deposited at high temperatures of 600 °C) as a cap layer followed by an aluminum oxide (Al2O3) ALD layer works for this purpose. The layer thickness of this double layer is only 20 nm and can be removed by wet chemical removal after annealing. This allows the layers to be easily integrated into the process. With annealing temperatures of 1400 °C, we have demonstrated very low layer resistances < 200 ohms/sq without GaN decomposition.
