ICNS-14: Two awards for Fraunhofer IAF researchers

Both awards at the 14th International Conference on Nitride Semiconductors (ICNS) went to researchers from Fraunhofer IAF: Akash Nair received the Outstanding Poster Award and Matthias Sinnwell was honored with the Best Student Award for his presentation.

Akash Nair, scientist in the field of growth of piezoelectric materials, was honored for his poster entitled “Controlling stress behavior of sputtered a-plane Al1-xScxN films”. There, the doctoral student describes how he and his group succeeded for the first time in growing aluminum scandium nitride (AlScN) layers in the non-polar direction while controlling the layer stress. This result represents a breakthrough for the growth of AlScN.

The piezoelectric material AlScN is considered extremely promising for industry, as it can be used for the development of acoustic wave devices, MEMS devices and components for high-frequency electronics. However, material growth has been a challenge so far: The growth of AlScN layers in the non-polar direction leads to positive material properties, but it has not yet been possible to avoid an increase in in-plane stress, which can have a detrimental effect on the film properties. For the first time, Nair and his group have now succeeded in finding a method for growing AlScN layers with an increased scandium concentration at low stress. This result is not only of great importance for the growth of AlScN, but also has the potential to enable new industrially relevant applications.

 Matthias Sinnwell, PhD student in the field of material characterization, received the award for his conference presentation on: “Fin-length scaling of vertical 100-fin GaN FinFETs on sapphire resulting in maximum frequency of oscillation fmax = 9.5 GHz”.

Fin field-effect transistors (FinFETs) are characterized by their narrow fin structures in the range of a few hundred nanometers. They enable positive threshold voltages, entirely without the use of p-doping, which is challenging in gallium nitride. While there is already some research into using FinFETs as voltage power devices, Sinnwell is investigating whether FinFETs can be used as power transistors at high frequencies beyond 1 GHz.

In his presentation, he was able to show a FinFET with a record value for a vertical GaN transistor in terms of its maximum oscillation frequency of 9.5 GHz, provide an estimate of the expected frequencies and present the first realization of the complicated FinFET structure at wafer level. 

About the International Conference on Nitride Semiconductors

The ICNS is a world-renowned academic conference and exhibition on group-III nitrides. The aim of the event is to present important scientific and technological advances in the field of materials and devices based on III semiconductors, to promote the exchange between researchers and thus contribute to the breakthroughs of these technologies. The 14^th ICNS took place from November 12-17, 2023 in Fukuoka, Japan.

As part of the conference, young scientists can apply for the "Best Student Award" and the "Outstanding Poster Award". The awards are presented to those who can demonstrate outstanding achievements and who are expected to make significant contributions in the nitride semiconductor field.