GaN-HEMT devices

Quality assurance of novel GaN technologies

Increasing digitalization in industry and private households, electromobility and the increased use of renewable energies are creating a growing demand for efficient and durable high-frequency and power semiconductor components. High-electron mobility transistors (HEMT) based on the wide bandgap semiconductor material gallium nitride (GaN) enable very high switching speeds to be achieved with significantly reduced power losses. The production is based on novel processes for epitaxially grown GaN substrates on silicon, sapphire or silicon carbide with circuit structures and is associated with a correspondingly high need of analysis with respect to process characterization and qualification as well as physical failure analysis. HEMT transistors are exposed to extremely high temperature and voltage loads during electrical operation, which leads to novel failure modes and degradation processes along with the direct semiconductor material used here. These must be identified and controlled in order to meet the application-specific requirements for performance, quality and reliability of III/ V devices.

Our expertise: high-resolution diagnostics and characterization techniques for GaN components

© Fraunhofer IMWS
(a) HRTEM image of the gate contact and (b) dark-field STEM with superimposed strain map in the [002] direction.

We posses in-depth expertise and comprehensive experience in process characterization and defect diagnostics of epitaxial GaN layers and GaN HEMT structures. For our work, we use state-of-the-art analytical techniques for defect localization, target preparation, atomic resolution structural analysis and trace analysis. Not least, we use our specific know-how in sample preparation and high-resolution electron microscopic analysis of GaN structures.

What you can expect: a broad understanding of GaN technologies and corresponding failure mechanisms

We support our partners :

  • with our sound expertise of material properties, manufacturing processes and transistor structures as well as corresponding defect mechanisms and failure risks
  • in clarifying process-related structural deviations and defect formations
  • in determining the cause of electrical malfunctions of HEMT transistors
  • in the development and application of appropriate analytical methods

Your benefit: improved performance and increased reliability

Our customers benefit from comprehensive insights into the microstructure of GaN HEMT devices, their technological weaknesses and defect formations. We contribute to the optimization of manufacturing processes to further improve the performance and reliability of GaN devices. As such, we support the qualification and market introduction of GaN technologies and devices for new applications in the fields of communication technology and power electronics. 

Services offered


Process and technology characterization


Failure diagnostics and clarification of failure mechanisms


Further development of analytical methods


Year Title/Author

Novel approach of combined planar and cross-sectional defect analysis of stressed normally-on HEMT devices with leaky Schottky gates

A. Graff a, M. Simon-Najasek a, S. Hübner a, M. Lejoyeux a, F. Altmann a, V. Zhan Gao b, F. Rampazzo b, M. Meneghini b, E. Zanoni b, B. Lambert 


Flyer: GaN-HEMT devices


Laser-induced activation of Mg-doped GaN: quantitative characterization and analysis

Arianna Nardo; Carlo De Santi; Chiara Carraro; Francesco Sgarbossa

Study and characterization of GaN MOS capacitors: Planar vs trench topographies

Kalparupa Mukherjee; Carlo De Santi; S. You; Karen Geens

Reliability and failure analysis of 100 nm AlGaN/GaN HEMTs under DC and RF Stress

Dammann, Michael; Baeumler, Martina; Kemmer, Tobias; Konstanzer, Helmer; Brueckner, Peter; Krause, Sebastian; Graff, Andreas; Simon-Najasek, Michél

Reliability Physics of GaN HEMT Microwave Devices: The Age of Scaling

Zanoni, E.; Meneghini, M.; Meneghesso, G.; Rampazzo, F.; Marcon, D.; Zhan, V.G.; Chiocchetta, F.; Graff, A.; Altmann, F.; Simon-Najasek, M.; Poppitz, D.

Reliability Physics of GaN HEMT Microwave Devices: The Age of Scaling

Zanoni, E.; Meneghini, M.; Meneghesso, G.; Rampazzo, F.; Marcon, D.; Zhan, V.G.; Chiocchetta, F.; Graff, A.; Altmann, F.; Simon-Najasek, M.; Poppitz, D.