In this interview, Jose Pozo, EPIC's CTO talks to Prof. Max Lemme, CEO of AMO GmbH, Aachen (Germany) and Chair of Electronic Devices at RWTH Aachen University where he researches on graphene and related materials and their application in electronics, photonics and sensors.

Background
After graduating from Aachen University with an MSc in Electrical Engineering in 1998, Max joined AMO GmbH, a partly government funded start up, which had been created in 1993 to enable technology transfer in nanotechnology. Initially, he worked as a research engineer while simultaneously studying for a PhD in Electrical engineering, which he completed in 2003. After his PhD, Max was given progressively more managerial responsibility and in 2006 he became head of AMO's Technology Department. In this position, he was responsible for setting up new clean room facilities and he significantly shaped the overall science and technology strategy of AMO in the area of microelectronics.

During this period Max worked on the development of the world's first transistor with epitaxial Gd2O3 gate oxide, the internal technology transfer from SOI electronics to silicon nanophotonics and the world’s first top-gated graphene transistor. In his PhD, he was also active in the development of Fin-FET transistors.

For Max, this was an exciting period because of the freedom they were given to follow unconventional routes and specify and purchase machines that were flexible enough to be reconfigured to work with new materials and technologies. But it wasn't all plain sailing: for example, when they first approached industry with a new transistor integration scheme they were told that AMO and its academic project partners didn't understand what industry wanted - that industry would never change from its current approach. But just a year or so later, Intel announced they were going to go exactly this new route and the integration scheme is now commonly used in industry. As Max says: "What I learned from this experience is that we as academic researchers are pathfinders and we need to follow unconventional routes that are not necessarily straightforward: our role is to show what can be done whether or not the big players decide to use it".

Move into photonics
The move into phonics started around 2004 and was a very logical step for AMO. Their Fin-FET experiments had been based on SOI material and they had developed very good etching processes. Furthermore, with their high resolution e-beam system they could do very rapid prototyping so the efforts they had already put in were extremely well suited to silicon photonics. During this period AMO began to participate on photonics projects with IBM Zurich and a number of other European partners.

Research on graphene
Max's research on graphene began in 2005. As he explains:

"We had always seen carbon nanotubes as having exciting potential for electronic integration and when graphene flakes came along that allowed, in principle, similar structures as SOI, we were convinced that this material could one day be grown into a productionable material that could be integrated into CMOS."

On the basis of the self-funded work they had done, Max successfully negotiated an industrial sponsorship from Infineon, Germany for a national grant proposal to continue the research. They had already worked together on Fin-FETs and high-k integration and in late 2006, the project ALEGRA kicked off as one of the NanoFutur junior researcher awards by the German Ministry of Education and Research (BMBF).

Academic research
In 2008, despite having just received the large 5-year government grant ALEGRA to work on graphene, Max decided to take up a research fellowship at Harvard University to work on graphene optoelectronics and helium ion microscopy. This was a risky decision, but it enabled Max to get back into pure research and gave him and his family the opportunity to experience living and working in a different culture. As Max adds:

"The experience was extremely enriching - talking to fellow researchers from Harvard and MIT in the clean rooms, famous people coming to give seminars on a weekly basis and being part of the American entrepreneurial spirit".

In 2010, for family reasons, Max and his family returned to Europe and Max continued his work on graphene technology as a visiting Professor at KTH Royal Institute of Technology in Sweden. Finally, in 2012, he fulfilled his long-term dream of becoming a full professor with a move to the University of Siegen as Heisenberg Professor of Graphene-based Nanotechnology. At Siegen, with the support of an ERC grant, he initiated research on analog graphene transistors and photodetectors and developed the world's first graphene hot electron transistors and graphene based piezoresistive pressure sensors in a nano-electromechanical system (NEMS), both still in close collaboration with KTH.

In 2017, Max was invited to move back to Aachen to work as a Professor at RWTH Aachen University, where he has since continued the work on electronic, optoelectronic and nanoelectromechanical devices and sensors made from graphene and related 2-D materials and their integration into silicon technology platforms.

AMO
On his return to Aachen, Max was also invited to become managing director of AMO GmbH, where he has since worked toward reinforcing the company's position as an effective entry point for new technologies particularly in the fields of graphene, nano fabrication and wafer level optics. As graphene technology is maturing, AMO now provides wafer level research and development of graphene devices, with the goal of becoming a pilot line, just as they are today for silicon and silicon nitride photonics.

Max likes to think of AMO as a pathfinder for new technologies. For example, they have just published a paper on perovskite based photonic integrated lasers, which many people consider are the missing link in the photonics field. They have been able to show how an optically pumped laser made from perovskites can be integrated into a wave guide - opening up the possibility of a cheap ubiquitous source of tuneable lasers.

AMO also plans to play an active role in the digitization revolution, which is often thought of as the conversion of text, pictures, or sound into a digital form that can be processed by a computer. But for Max, digitization is as much about hardware as it is about software. As an example, he cites GPUs (graphics processing units) which are specialist circuits used to manipulate and alter memory to accelerate the creation of images. Originally designed for computer games, they are now also heavily used in research to facilitate pattern recognition to enable AI and machine learning. But the high performance comes at a cost - GPUs consume substantial power. Here, the development of new materials, devices and circuits for neuromorphic computing is an exciting research topic, where researchers are trying to emulate the neural structure of the human brain in hardware. Such “Neuro ICs” may be able to provide the performance required for future autonomous systems, at a fraction of the power consumption.

Digital Hardware Hub
AMO's overall aim is to become a Digital Hardware Hub and be part of the very active Incubator landscape in Aachen, which supports SMEs and start-ups. AMO aims to specifically become the semiconductor hardware Incubator and to help develop ideas into functioning device demonstrators, that can be used to obtain funding, attract investors or to show the scaling path towards production. Currently, because of the costs involved, start-ups and small companies cannot build clean room infrastructure from scratch or build up the technical expertise they need to develop their ideas. To bridge this gap, AMO will provide access to a clean room and other facilities and the technical advice to help accelerate research in a number of fields. For example, in the areas of biotechnology and environmental sensing, AMO are currently collaborating with companies to develop customised solutions for diagnostic optical detectors or gas sensors on wafer scale.

What would you have done differently?
"Not much, because I ask myself a similar question each time I make an important decision: that is, what will I think about the decision I'm making now when I look back in 5 years' time? If I am confident that I will answer to myself that it was reasonable and forward looking based on what I knew then, there should be no reason to look back with regret. I've always been guided more by instinct and passion than anything else and so far, I haven’t regretted any of the decisions I've made".

Advice for young entrepreneurs
"First, you should be driven by your passions. Don't do a PhD or a postdoc just because it will enhance your career opportunities or it's an easy way out. Do it because you're passionate about the research area. If you're passionate about something, you'll be good at it and you're more likely to be successful".

“Second, create options and have a plan B. When you are ready for the next step, it is always good to have at least one other option on top of your favourite choice. Life is competitive and there is always a good chance that someone else will get the position, the venture capital funding or the project you thought you would get. The best problem to have is one to decide between several great options. And remember, even the best CVs often only appear so in retrospect, but in reality included setbacks, disappointments and (what seemed at the time) second options.”

"Third, your family can be a great source of support in your career, so try to take them along in your decisions. If you have kids, especially young children, make sure you find the time to be there for them".

Written by Jose Pozo, Director of Technology and Innovation, EPIC