University of Bristol
Center For Device Thermography and Reliability







Phonon frequency vs. T

Welcome to the Center for Device Thermography and Reliability (CDTR)

The CDTR is a world-leading center focused on improving the reliability of novel devices, circuits and packaging, by applying key technologies developed in Bristol since 2001 for high spatial/temporal resolution thermal and stress analysis of semiconductor devices. This is particulary important for new technologies, during the development phase. Examples include GaN power electronics and new high-power GaAs components. We focus especially on factors such as temperature and stress-related device failure.

The strength of the CDTR lies in the development of novel and unique technologies, and their application to assess devices and circuits. For example, this not only includes high spatial/temporal resolution thermal and stress analysis using Raman Thermography developed here, but also other standard complimentary techniques for failure analysis, e.g., FIB and TEM.

The CDTR is active in several key EU, US, and UK programs. Projects and developments are defined and targeted through interaction with relevant national and international industries. This enables the targeted development of new techniques in order to address specific industry challenges. The practical analysis of devices, circuits and packaging is strengthened by thermal and thermo-mechanical simulations, helping to define design rules for novel technologies.

If you are interesting in working with us, and contributing and defining to projects, please get in touch with us.

Current contributors include: Qinetic (Malvern), Selex (SAS), IMEC (Belgium), UMS (Germany), Thales-Aliena (France), Northrop-Grumman (USA), Raytheon (USA).

Director of Center: Prof. M. Kuball

Recent News

19.12.2013. We have an opening for a PostDoc in Advanced Electrical Characterization and Reliability of AIGaN/GaN and SiC transistors. Please see here.

19.12.2013. We are happy to welcome two members who will join our group shortly, Alexander Pooth who will join us from RWTH Aachen in Germany, and Dr. Tommaso Brazzini who will join us from the University of Madrid in Spain.

01.10.2013. We have an opening for two PhD student positions. Please see here.

01.10.2013. We have an opening for one PostDoc on GaN HEMT RF reliability. Please see here.

21.03.2013. CDTR article published in Compound Semiconductor magazine: "GaN HEMTs, Tracking an electrons journey".

09.01.2012. Dr. Mirko Bernardoni joined our group as postdoc.

09.01.2012. Nicole achieved the Student Honorable Mention Paper Award 2012 on CS Mantech 2011.

other news...

19.09.2011. Dr. Marco Silvestri joined our group as postdoc.

17.05.2011. Our work on thermal interfance resistance in GaN-SiC electronics has received the He Bong Kim Award of CS Mantech 2011.

05.04.2011. We have an opening for PostDoc on GaN HEMT reliability. Please see here for more details and how to apply (application deadline is 20 June).

21.4.2011. Novel work on the determination of phonon dispersion curves of InN has been accepted for Physics Review Letters. See here for a prerint.

22.2.2011. Meet us at CS Mantech in May 2011 in Palm Springs California. Nicole Killat will present her work on impact ionization in GaN HEMTs.

20.2.2011. First clear illustration on role of impact ionization in GaN HEMTs is accepted for publication in Electronics Letter. See here for a prerint.

3.10.2010. Welcome to Janina Moereke and David Spiteri who joined as PhD students the group.

1.9.2010. Welcome to Dr. Miquel Montes who joined as Post Doc the group.

23.7.2010. IWN 2010 in Tampa Florida is coming up ... meet us (Martin Kuball, Milan Tapajna, James Pomeroy) to get more information what we are presently working on.

20.7.2010 New PhD studentship positions in Center for Device Thermography and Reliability (CDTR), University of Bristol, United Kingdom: GaN and GaAs Transistors.

14.7.2010. Bristol is co-organizing a Boron focused symposium on the MRS Fall Meeting in Boston this year. See here for more details.

7.7.2010. We recently identifed diffusion processes in GaN HEMT to play a key result for early device degradation. Those results were just published in Applied Physics Letters.

01.4.2010. Our latest results on trap generation, and combined electrical-optical reliability analysis of AlGaN/GaN HEMTs have just been accepted for publication in IEEE Electron Device Letters.

01.4.2010. New project MANGA funded by EDA has been approved. This is a pan-European project of leading GaN electronic device manufacturers and researchers.

18.3.2010. New EPSRC project, on novel technique developments on GaN HEMT reliability has just been approved. The techniques to be developed will enable unprecedented insight into the workings and reliability challanges of AlGaN/GaN HEMTs, and will involve a few of our long-standing key international collaborators. More details can be found on the EPSRC website.

25.2.2010. Post-Doc Position available on Tera-Hertz Gunn Diodes in Center for Device Thermography and Reliability (CDTR).

15.01.2010. Gernot Riedel passed successfully his PhD viva. Congratulation Dr. Riedel!

11.01.2010. Upcoming conferences with CDTR presentations: Mantech, Portland, USA / May (Martin Kuball, Mustapha Faqir), IRPS, Anaheim, USA / May (Nicole Killat, Milan Tapajna).

26.08.2009. Upcoming conferences with CDTR presentations: ISCS Santa Barbara / September (Martin Kuball, Milan Tapajna), ICNS Korea / October (Athikom Manoi), MRS Fall Meeting / December (Martin Kuball, Yinyan Gong, Silvia Bakalova, Tim Schuller).

26.08.2009. Prof. Mike Uren (QinetiQ) has been appointed Visiting Professor in Bristol and the CDTR, based on our long-standing collaboration with Mike Uren & QinetiQ.

24.03.2009. Upcoming conferences with CDTR presentations: MRS Spring Meeting, San Francisco (13-17 April 2009) and MANTECH Workshop (18 May 2009) and Conference (19-21 May 2009), Tampa, Florida.

02.02.2009. We welcome Silvia Bakalova to the group as a post-doctoral researcher and Nicole Killat to the group as a PhD student.

14.01.2009. We welcome Milan Tapajna to the group as a post-doctoral researcher.

23.12.2008. Modifying the nucleation between a GaN device and the SiC substrate can reduce AlGaN/GaN power electronics temperature, and therefore improve device reliability. This work has just been accepted to IEEE Electron Device Letter 2009. See here for more details.

01.11.2008. Center for Device Thermography and Reliability (CDTR) officially founded.

01.10.2008. Dr Yinyan Gong joins our group as a post-doctoral researcher to work on novel boron materials.

25.07.2008. Want to talk to us ? Want to learn more about us ? See us at IWN 2008 in Montreux, Switzerland, in October where we will present our work in 2 talks and 2 posters.

31.03.2008. New Group Photo posted.

08.01.2008. In the press: The Engineer (December 2007).

21.10.2007. New EPSRC grant awarded jointly with Sheffield University to develop novel UV laser diodes.

01.10.2007. Professor Ramakrishnan from Madurai Kamaraj University, India, is visiting us with Commonwealth Fellowship for 6 months.

16.09.2007. We have presented our work at TMS7 in Las Vegas, USA. These photos show highlights of our stay there.

01.09.2007. We welcome Athikom Manoi and Tim Schuller to the group as PhD students.

01.04.2007. Dr. Sarua is appointed as GWR Research Fellow. He will perform research on new sensors using wide bandgap semiconductors.

01.02.2007. We welcome James Gray who just joined the group as PhD student.

20.11.2006. Development progress report of a Pulse InVia system for time-resolved device charaterisation.

05.10.2006. Richard Simms joined our group as Ph.D. student.

27.09.2006. New DC/pulsed Keithley parametric analyser installed and operational.

01.09.2006. Dr. Eleanor Edwards jointed our group from HP.

14.07.2006. Expansion of our research facilities with extra lab space for pulsed laser work started.

01.07.2006. James Pomeroy started as a post-doc RA in our group.

March/April 2006. Our group has been awarded two EPSRC grants, one to develop the in Bristol pioneered Raman thermal device imaging further (collaboration between Bristol, Glasgow, QinetiQ, Selex, Renishaw), the other on developing new boron based materials (collaboration between Bristol, Kansas State University and SUNY Stony Brook).

25.10.2005. Another feature about our research activities in Compound Semiconductor magazine, follow link.

01.10.2005. Our research activities have recently featured in III-V Review (Sept/Oct 2005 issue) article. An additional feature is on the University of Bristol Re:search site.

23.09.2005. Gernot Riedel from Karlsruhe, Germany joined us as a Ph.D. student.

08.09.2005. New Ph.D. student Tim Batten joins our group.

20.05.2005. Installation of IR camera on Renishaw InVia spectrometer. John McDonald from QFI (San Diego, USA) was visiting our group and upgraded us with new InSb 256x256 IR camera and lots of extras. Now fast overview temperature maps are possible as pre-targeting system for our patented Raman thermal imager.

16.05.2005. Participation in WOCSDICE 2005 meeting in Cardiff.

01.10.2004. Hangfeng Ji from Zhejiang, China joined us as a Ph.D. student.

30.06.2004. Arrival of a brand new Renishaw InVia system, equipped with 488 nm Ar and 785 nm diode lasers and 0.1 um XY-stage.

18.03.2004. Start of new EPSRC project on thermal mapping in III-V devices.

01.03.2004. Start of our new website.