Materials
Materials and Surface Science for EUV Lithography
About
The Materials & Surface Science for EUV Lithography (MatSurf) group studies how material surfaces evolve in reactive environments, such as the hydrogen-rich environment of EUV lithography. To do this, we expose well-defined surfaces to plasma-activated gases and follow reaction steps at their surfaces live using in situ spectroscopy.
Research focus
In EUV lithography, materials are placed in a peculiar environment: a low-pressure non-thermal plasma. This plasma contains highly reactive species such as ions and radicals, which change surfaces, coatings, and even bulk materials. While similar conditions are also relevant for materials in space, and for novel catalysis approaches using plasma-activated molecules, it is not well understood how plasmas change surfaces at the atomic scale. In the MatSurf group, we build a bridge between plasma applications and the fundamental understanding provided by in-situ surface science.
One of the most common methods of electron spectroscopy makes use of the photoelectric effect: the emission of electrons from chemical elements upon irradiation with X-rays or UV light. The energy of the radiation is transferred to an electron with a well-defined binding energy, which needs to be overcome for the electron to leave the atom. The emitted electron carries the remaining energy as its kinetic energy. This kinetic energy is measured and, together with the known energy of the radiation, allows us to calculate the binding energy of the electron, which is characteristic of the chemical element and its oxidation state. This technique, X-ray photoelectron spectroscopy (XPS), tells us what is happening on the surface at the atomic level.
Electrons interact strongly with matter, so XPS has traditionally required ultra-high vacuum conditions during measurements. However, advanced designs using differential pumping and electron optics allow for experiments at elevated pressures (near-ambient pressure XPS, NAP-XPS). In the past two decades, XPS at elevated pressures has advanced in multiple ways, resulting in a higher accessible pressure range, optimized designs for electrochemical experiments, and even NAP-XPS during exposure to radicals, ions, and plasma. We’re among the first groups performing XPS during plasma exposure, providing insight into the time evolution of surface chemical processes and reaction kinetics in plasmas.
Group members
Roland Bliem leads the Materials and Surface Science for Extreme Ultraviolet Lithography group at ARCNL and is Associate Professor at the University of Amsterdam (UvA). His research focuses on the physical and chemical changes to surfaces at the extreme conditions of EUV lithography, including reactive environments, high temperatures, and high-intensity radiation.
Latest news
Most recent publications
