InRel-NPower in brief

The way in which electric energy is used has great impact on the economy, the environment and society. However, a major part of the produced electricity is lost in electric power conversion. To reduce such losses we must create electronic devices that use new materials with higher efficiency.

The InRel-NPower project researches GaN and AlN-based transistor devices for application in power electronics. These material could result in conversion systems achieving a 99% conversion efficiency!

We aim to mature the technology: by focusing on the raw material, on the packaging and by demonstrating its potential in a final device.

Results from WP1 - Material and Epitaxy

Our goal is the development of mature heteroepitaxial GaN- and homoepitaxial AlN-wafers. Firstly, a broadly scoped study of the GaN-on-Si wafers enabled substantial improvements of the electrical performance, but also new understanding and insights into the physical mechanisms that are at the origin. Secondly, very high epitaxial quality of AlN films is targeted through regrowth on AlN-templates and frestanding AlN-substrates.

From the lab: 

• Direct evidence of the criticalness of defects within the buffer (Read more)
• AlN with very high crystal quality on sapphire characterised (Read more)

Results from WP2 - device processing

Our goal is the optimization and qualification of GaN-on-Si power device processing on a 6-inch pilot line while targeting on-resistance < 20mΩ for 650V applications. Furthermore, we will develop devices for beyond 2000V applications by optimizing the substrate-removal technique for GaN-on-Si technology as well as achieving novel power devices based on bulk AlN.

From the lab: 

• Substrate removal results in enhancement of breakdown up to 3kV (Read more)
• Normally-off devices setting new process of record (Read more)

Results from WP3 - Advanced Characterization & Reliability

Our goal is to identify specific limitations in terms of parasitic effects and reliability issues for GaN lateral power devices. Focus is on the identification of degradation mechanisms and prediction of physical models/laws, which can be used for accurate lifetime extrapolation and qualification for GaN based power devices.

From the lab: 

• Achievement of lower Dynamic ON-Resistance as compared to Competitors (Read more)
• Understanding of the Degradation Mechanisms of the pGaN Gate (Read more)

Results from WP4 - Packaging and demonstrators

Our goal of this last technical work package will be the development of two innovative packaging systems and two demonstrators in order to fully exploit the potential of the GaN devices

From the lab: 

• DC2AC converter (CE+T) built up with GaN Systems power devices and SiC (CREE)(Read more)
• Realization of first prototypes for the motor drive output stage with pre-driver and signal conditioning(Read more)

Free summer school on GaN

You may have had the chance to meet us at our previous summer school in Brixen (Italy) during the summer of 2017, together with 70 other participants.

Several lectures were given by members of the consortium, which will be made available on our YouTube channel!

• "General Overview of GaN based Power devices"
  by P. Moens (ONSemiconductor)
• "Materials and Epigrowths for wide bandgap semiconductor devices"
  by J. Derluyn (EpiGaN)
• "Defects in Nitride semiconductors materials and their relevance to electronic devices"
  by E. Meissner (Fraunhofer IISB)
• "Device processing and architectures in Gallium Nitride based semiconductors"
  by F. Medjdoub (CNRS-IEMN)
• "Reliability of GaN-power transistors: an overview"
  by M. Meneghini (Padova University)
• "Modern high performance assembly and interconnection technologies for wide-band-gap power semiconductor basing power electronics"
  by M. Rittner (Bosch)
• "Industrial applications of wide bandgap semiconductor devices"
  by K. Kriegel (Siemens)
• "Applications in Energy saving of wide bandgap semiconductors devices"
  by P. Bleus (CE+T)

InRel-NPower extended by 6 months

The wish for easy realization of a GaN-HEMT device leads typically to normally-on devices. The fastest way to fulfill the normally-off condition in power electronics system topologies is the cascading of the high performance GaN device with a low-voltage blocking Si-MOSFET device. Nevertheless, using the cascaded configuration has some certain disadvantages on all three technology (sub-)system levels: device level, packaging/module level and aggregate/vehicle level.

These disadvantages led to a shift of device demand during the first phase of our project. Now the demand for a true intrinsic high voltage blocking normally-off GaN devices exists. To achieve this changed objective, the InRel-NPower project was granted a 6-month extention without additional financial recourses.