Erwin Kessels Interview

How does someone become successful in his/her job? My suggestion is to ask Dr. Erwin Kessels.

There is no doubt that he has accomplished a lot in his career: he became a full professor at a young age, is a sought-after speaker at international conferences, has authored more than 200 publications and recently became Associate Editor of the Journal of Vacuum Science & Technology. In my opinion, what makes him even more successful is that he is a well-rounded person with a lot of hobbies and interests besides science, he is also very approachable and pleasant.

Daphne Pappas


Prof. Erwin Kessels, Eindhoven University of Technology

Prof. Erwin Kessels, Eindhoven University of Technology

Dr. Erwin Kessels’ Interview to The Science and Engineering Cafe


What made you choose plasma as your field of study and what made you shift your focus to atomic layer deposition?

Good question! But I’m still working on plasma (processing) and atomic layer deposition! I very much like the plasma physics and plasma chemistry related to processing plasmas. It is a very nice combination of gas and charged particle kinetics, electromagnetism, reaction kinetics, and surface science. So it is a very broad and diverse field that involves all kinds of physics and science (among plasma researchers there are physicists, chemical engineers, and electrical engineers, etc. A nice mix!). I got excited by the field after taking the class Introduction to Plasma Physics as an MSc student. The lecturer, Prof. Daan Schram (who later became one of my advisors), demonstrated that one could calculate or estimate a lot about plasmas even when little information is available. “Take a sodium street lamp” he asked during the oral examination, “What is the electron temperature and density”?

The other thing about plasma processing that I like a lot is that it is very relevant in the areas of microelectronics and solar cells. I find these application areas fascinating. Think about Moore’s law and how smart scientists and technologists have been proven to stick to it in the last decade. Solar cell technology is very cool too. And it is of course very important for our sustainable future.

When I learned about atomic layer deposition (ALD), after having worked mainly on plasma-enhanced chemical vapor deposition (CVD), I got excited by all the possibilities plasmas can provide to this method as well. Think about low temperature ALD or ALD of difficult to prepare materials. Moreover, it is much easier to understand the surface reactions during plasma-enhanced ALD (compared to plasma-enhanced CVD) as the plasma chemistry is not as “complicated”. During plasma-enhanced ALD, fairly simple plasmas (plasmas of O2, N2, H2) are used such that the plasma and surface chemistry becomes much simpler than in, e.g., a plasma used for the deposition of silicon-based films with plasma-enhanced CVD.


Has the technology that you are working on been commercialized?

Yes, with our research we have been quite successful in that respect. During my PhD research, which was about plasma-enhanced CVD of amorphous silicon for thin film solar cells, I did a side project on plasma-enhanced CVD of silicon nitride for crystalline silicon solar cells. Finally, the deposition technique that I worked with (the so-called Expanding Thermal Plasma) got commercialized by the company OTB Solar (which later became part of Roth & Rau and which is now part of Meyer-Burger). This company sold many high-volume manufacturing tools for silicon nitride to major solar cells companies. In our lab we have a few commercial solar cell panels which have silicon nitride coatings prepared by the technology developed in our lab.

I have also been successful with our plasma-enhanced ALD research. Our home-built system, that we started working with in 2003, served as a kind of example for the tools developed a few years later by the company Oxford Instruments. Our university even served as a beta-site for their first tool as it was placed in our clean room. Since then we have had a long-standing collaboration which is still active at present.

A third prominent case is the use of Al2O3 nanolayers in crystalline silicon solar cells. Most solar cell companies are currently launching solar cell panels with solar cells that contain such nanolayers for the passivation of the silicon surface. This development has been triggered by our initial work on ALD of Al2O3 films which dates back to 2005. With our results we demonstrated that Al2O3 prepared by plasma-enhanced ALD yields an excellent level of surface passivation. This “discovery” has also contributed to start-up companies working on spatial ALD such as SolayTec and Levitech.

Well, as you can see I’m pretty proud about our work.


Do you have any hobbies or special interests?

Sure, there is more than just work. Although I have to admit that I’m a workaholic. Being a scientist and university professor is not just job, it’s a way of life. Yet I do have other interests that can well be combined with my “job”. For example, I like to travel and explore new places I have never been to before. Rather than just sightseeing I like to experience other countries, cities and cultures. Am I lucky that I get to travel to many conferences 🙂 ? I also like sports, especially running, biking, and swimming. These sports can also be done when being “on the road”. I just returned from an extensive trip to Australia and the U.S. and I combined swimming in the Indian Ocean and skiing in the Sierra Nevada. Furthermore, I have my favorite running trails in (conference) cities like Boston, London, Los Angeles, Paris, Portland, San Jose, and Washington. The other thing I’m very much interested in is art. I’m especially into modern art such as modern (not contemporary) paintings and sculpture. And all the travel to conferences provides great opportunities to visit museums, exhibitions and art galleries. As you see, life is good being a scientist!

%d bloggers like this: