ISPSD 2016 Best Paper Award

Integration of GaN HEMTs onto Si CMOS

by Micro Transfer Printing

Abstract GaN HEMTs on silicon substrates were heterogeneously integrated onto CMOS wafers by micro-transfer-printing. GaN HEMTs were processed in a GaN on silicon process, made “print ready” by removing the adjacent and underlying material and transfer-printed with a viscoelastic elastomer stamp onto a standard CMOS wafer. The flexible combination of superior electrical parameters of GaN based HEMTs with the large logic functionality of silicon based CMOS could enable cost effective and high performing high voltage power ICs. The undisturbed transistor parameters of printed GaN HEMTs as well as the native CMOS demonstrate the technical feasibility of this approach to integrate GaN power devices into CMOS logic.


Ralf Lerner received his diploma in material science from the University Erlangen-Nuernberg, in 1993. After working 3 years at the University of Erlangen-Nuernberg in the field of (compound semi­conductor) crystal growth he joined X-FAB Semiconductor Foundries AG in 1996. He is working as a project manager in the process development group on trench isolation SOI technologies and integrated high voltage Power IC processes and devices. He is author and co-author of about 20 publications, author of about 40 granted patents.

Stefan Eisenbrandt received the B. S. and M. S. degrees in electrical engineering and information technology from the University of Applied Sciences in Schmalkalden, Germany and the University of Technology in Ilmenau, Germany in 2014 and 2015, respectively. He joined X-FAB in 2016 as a process development engineer for high-voltage devices. His interests include the fabrication, characterization and TCAD of Silicon and GaN based high-voltage devices.

Christopher (Chris) A. Bower received a Ph.D. degree in physics from the University of North Carolina, Chapel Hill, in 2000. After working as Technical Manager at Semprius, Inc. He currently works as Chief Technology Officer at X-Celeprint Limited. His interests include three-dimensional integration of integrated circuits, heterogeneous integration of compound semiconductors onto non-native substrates and the fabrication of low-cost, large-format electronics using novel assembly methods.

Salvatore Bonafede earned his Ph.D. degree (Chemistry) from the University of Nebraska at Lincoln and his B.S. degree (Chemistry) from the University at Buffalo. In 2014 he joined X-Celeprint (US) Inc. working as a Senior Process Scientist. His primary responsibility is micro-fabrication process development leading to the advancement of micro-transfer printing technology and applications. He has published in the areas of micro-transfer printing methods and applications, micro­electronic interconnection and packaging, polymer characterization, and solid-state chemistry.

Alin Fecioru received the B.S. and M.S. degree in Applied Physics from the university of Iasi, Romania, in 2000 and 2002 respectively. In 2005 Alin received his Ph.D. degree from the Max Planck Institute of Microstructure Physics and the Martin Luther University in Halle. He joined X-Celeprint Ltd in 2014 and is working as Senior Development Scientist. Main focus of his work is the development of flexible transfer printing techniques e.g. for GaAs and GaN based µLEDs.

Richard Reiner studied electrical engineering at Technical University of Berlin, concentrating on high-frequency and microsystem techno­logy. He completed his master’s degree in 2007. Since 2010, he has worked as a research associate at the Fraunhofer Institute for Applied Solid State Physics IAF in Freiburg on the development and character­ization of GaN-based devices and circuits for power-electronic applications.

Patrick Waltereit received the Diploma degree in Physics from the Free University Berlin, Germany, in 1998 and the Ph.D. degree in Physics from the Humboldt University Berlin, Germany, in 2001 where he grew and characterized the first non-polar oriented GaN/AlGaN heterostructures. Since 2004 he is with the Fraunhofer Institute for applied solid state physics in Freiburg, Germany, where he is involved in project development and technology for GaN-based electronic devices. He has authored or co-authored over 100 technical public­ations and conference presentations.