This group studies surfaces, interfaces, and very thin films on the atomic scale. The knowledge it generates is relevant for the delicate optics and other essential components of modern lithography machines.

Special lenses are required for EUV light, in the form of mirrors that often contain dozens of extremely thin layers. How can they be made atomically flat, how can intermixing of the layers be avoided, and how can they be protected from the harsh operating conditions? Answering these questions requires insights at a fundamental level, supported by direct observations on the atomic scale. Another inspiring subject is friction. How does it originate? The answer is very relevant for lithography, since the friction between a silicon wafer and its support can distort the wafer. As electronic circuits become increasingly miniaturized, even the slightest distortion could become detrimental.

Thirdly, graphene and other materials with a thickness of one single atom form an attractive class of films that may protect optical components and reduce friction. This group works on novel ways to build such films atom by atom, with the structural perfection required for such new applications.

For its experiments, the Nanolayers Group has constructed its own unique instruments. For instance a scanning tunneling microscope (STM) that can ‘see’ where a single atom lands on a surface and an STM that operates on materials as hot as 1000°C.