From accumulating deep expertise to his work ethic on research excellence and developing the next generation of Research Leaders, Senior Staff Researcher and PI Ray Duffy shares insightful advice.
Following my BE, MEngSc, and PhD at UCC, I invested many years in industrial research at Philips Research Leuven, and NXP Semiconductors, based at IMEC in Belgium. This gave me practical experience in working for industry, with real-world problems to solve for real product lines, namely silicon chips that would go into consumer electronics products like smartphones, while at the same time working on research challenges, which can often boil down to solving complex problems from scratch. I enjoyed the pace of industry, coupled with that freedom to brainstorm new or novel ideas, all contained within a dynamic work culture. There’s always a great buzz when you realise you’ve worked something out.
Eureka!
Accumulating Deep Expertise and Producing Impactful Projects
I was originally inspired, and am still inspired, by research because I like learning and discovery. It’s great when experiments work out as planned, but often you will discover something unexpected – “Wow I wasn’t expecting that” or “Okay, that’s something I haven’t seen before”. Not every unexpected result is a breakthrough, but if you can figure out what you’ve got or why that unusual thing is useful, then that’s a breakthrough.
Still, it always comes back to “learning new things.”
Some of the most important steps I’ve taken in terms of developing my own ‘deep’ expertise stem from everyday life lessons and routines such as this and more - learning from mistakes, working hard, reading, talking to experts, listening. These small yet consistent steps have helped me to grow my expertise and create real impact in research and industry projects that I am incredibly proud of.
Some examples include:
Air sensitivity of MoS2, MoSe2, MoTe2, HfS2, and HfSe2 (2016) Journal of Applied Physics, 120 (12), art. no. 125102. This is an early work from our group in this field, a systematic screening of stable 2D materials which has already been cited 63 times since 2016.
Atomically flat low-resistive germanide contacts formed by laser thermal anneal (2013) IEEE Transactions on Electron Devices, 60 (7), art. no. 6530663, pp. 2178-2185. This paper shows the power of laser annealing for material modification in semiconductor device applications and successfully generated patent applications, European (EP13153312.7) and US (US 61/758,716).
Physics-based modelling of MoS2: The layered structure concept (2019) Semiconductor Science and Technology, 34 (5), art. no. 055015. This is a ground-breaking paper, with a new concept for the device modelling and gaining insight into these layered materials. Other highly cited papers can be found on my Google Scholar profile.
Conceiving the novel technique “1.5D SIMS” - a novel technique to profile impurities in non-planar devices by Secondary Ion Mass Spectrometry (SIMS). This characterisation technique was adopted by the industry such as Intel, Applied Materials, TSMC among others and has translated in the improved development and manufacturing of microprocessors in billions of portable electronic devices. The aim of this metrology technique is to provide detailed information regarding the sidewall impurity concentrations in Si FinFET structures, with a relatively quick turnaround for sample preparation and analysis. It is this aspect that makes it practical in terms of information collection without long lead times or intense data post-processing. This practicality made the 1.5D SIMS approach attractive for uptake by many companies like Intel, Applied Materials and TSMC.
Multi-disciplinary collaboration with the UCC School of Chemistry in the area of monolayer doping - this partnership has worked by bringing together complimentary perspectives (device and dopant physics with organic chemistry), which has made a significant impact in the academic field in terms of high-impact journal publications. Had each of our groups worked in isolation, our work would be publishable, but by joining forces we were able to achieve higher-impact publications together.
My role at Tyndall has fortunately enabled me to maintain and foster strong links in industry with multi-nationals such as Synopsys, Excico, and Lam research in the last number of years as well as project collaborations with -
Applied Materials - I have been a co-PI on international collaborative research projects with Applied Materials, the world’s largest supplier of semiconductor processes and equipment, in the Enterprise Ireland Innovation Partnership Programmes since 2015 to the present.
Intel - I have engaged with Intel from 2013-2017, presenting at Intel-Ireland Programs Review Oct. 2011, Nov. 2012, and Nov. 2015 at Intel Components Research in Portland OR, USA.
Research Excellence at the Core
Research excellence has always been firmly rooted in my work ethic.
I was the first to report and flag the issues of doping FinFETs by ion implantation which is the conventional method of introducing dopant impurities into Si. Essentially the ion bombardment destroys the Si crystal, and due the presence of many surfaces in the FinFET, it is very difficult to recover the crystal quality by thermal annealing. Up until then a dramatic loss in electrical performance was not understood, before this work in 2007. This breakthrough made the industry rethink their methods to dope FinFETs. A first proposal of hot implantation as a solution for reducing crystal damage in FinFET devices was in 2008, which is now an industry standard. To put this in perspective FinFETs are now at the heart of high-end Smartphone microprocessors such as in the Samsung Galaxy and Apple iPhone. Billions of people have FinFETs in their mobile devices, which have transformed society in the past decade.
Our work in the SFI 09/SIRG/I1623 project was cited by TSMC R&D as the state-of-the-art for Ge doping and contact formation. TSMC is the world's largest independent semiconductor foundry and they are seriously considering Ge as a replacement for Si in logic CMOS devices and products, again with markets in microprocessor components. Our paper concerns the formation of low-resistance contacts to Ge devices using laser thermal annealing. By this process complex alloys of nickel-germanide are formed which are both structurally and electrically superior to germanides formed by conventional thermal anneal.
Developing Early Career Researchers / Next Generation Leaders
For me, what has always been the most fulfilling part about my role and a key output from research in Tyndall is enabling students in their studies and empowering them to secure jobs in industry. I do my best to help our students overcome any barriers or fears and raise their ambitions in the process.
For example, Dr. Ran Yu worked in my research team until 2013. At one point he considered writing up his first 2 years work as a Masters. By working together through that period, Ran persisted with his PhD, he worked incredibly hard and effectively, and as it turned out he produced a marvellous thesis with many highly cited journal articles, and has since worked in industry for Synopsys in Singapore.
Recently Dr. Gioele Mirabelli, under my supervision, won the BOC Gases Bursary Postgraduate Award 2019 at Tyndall National Institute for his research on Two-Dimensional Semiconductor Materials for Future Electronics.
Tyndall National Institute.