We are looking for a motivated and skilled PhD researcher to investigate the physical and chemical degradation processes of novel ultra-thin freestanding films. These transparent membranes are used as protective transparent windows ('pellicles') in EUV photolithography, where they are placed just above the sensitive photomask to prevent its contamination by particles. The membranes need to resist not only thermo-mechanical stresses, but also surface degradation by EUV photon induced chemical reactions, bombardment by low energetic ions, and chemical etching by radicals. The aim of the project is to develop fundamental knowledge on the film EUV-induced degradation mechanisms and find materials and processes that can mitigate pellicle damage.
The PhD research will focus on pellicle EUV exposure and transmission experiments which will be executed at the MESA+ facilities of the University of Twente and at the PTB synchrotron laboratory in Berlin. The goal is to understand, model and experimentally investigate damage mechanisms occurring on new materials in an EUV induced plasma environment. In this research the understanding of the complex physics at play is essential.
Your tasks will be to prepare (design, plan and discuss) and execute the experiments that lead to a better understanding of pellicle damage mechanisms. You will analyze thin films of interest with high precision using surface-sensitive analysis equipment (XPS, LEIS, AFM, …) to understand the sample's surface composition and structure, before and after degradation experiments. You will construct analytical models to explain the observed surface modifications and test such models against (EUV) exposure conditions.
The project will be carried out in the Industrial Focus Group XUV Optics
where a new multidisciplinary research programme on thin film EUV optical devices has already started. The group develops forefront fundamental research, relevant to high-tech, industrial focused applications (www.utwente.nl/xuv/). The research will take place in a state-of-the-art thin film laboratory within the MESA+ Institute for Nanotechnology at the University of Twente, in collaboration with various industrial partners and PTB.