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]( https://www.utwente.nl/en/tnw/xuv/) 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.

• You have a Master's degree in solid state or plasma/photo-surface physics, materials science, light-matter interaction or a related field.
• You have lab experience with plasma, thin film deposition and/or thin film analysis setups.
• You have affinity with the realization of physical or chemical depositions of nanoscale thin films (MEMS, CMOS or related) and their optical, structural, and mechanical analysis.
• You are an excellent team player in an enthusiastic group of scientists and engineers working on a common theme. You will design, discuss and execute key experiments at the MESA+ and PTB Laboratory at BESSY II in Berlin.
• You are creative, like to push boundaries, and are highly motivated to address major open science challenges in thin film physics.
• You are fluent in English and able to collaborate intensively with industrial and academic parties in regular meetings and work visits.

• Be involved in industry-relevant research using state-of-the-art equipment
• Fulltime PhD position for four years
• Enthusiastic colleagues and stimulating scientific environment
• PhD salary € 2.541 in first year, increasing to € 3.247 in the fourth year
• Minimum of 29 holidays and holiday allowance of 8% of the gross annual salary and a year-end bonus of 8.3%
• Numerous professional and personal development programmes

The University of Twente stands for life sciences and technology. High tech and human touch. Education and research that matter. New technology which leads change, innovation and progress in society. The University of Twente is the only campus university in the Netherlands. We have a strong focus on personal development and give scope for carrying out pioneering research. The Faculty of Science & Technology works together intensively with industrial partners and researchers in the Netherlands and abroad and conducts extensive research for external commissioning parties and funders.

The XUV Optics group is embedded in the MESA+ Institute (www.mesaplus.utwente.nl), which is one of the largest nanotechnology research institutes in the world, delivering competitive and successful high-quality research. The institute employs 500 people of which 275 are PhD's or PostDocs. With its unique NanoLab facilities the institute holds 1250 m2 of cleanroom space and state-of-the-art research equipment.

The University of Twente is an equal opportunity employer which values diversity. We do not discriminate on race, religion, color, national origin, gender, sexual orientation, age, marital status, or disability status. Because of our diversity values we do particularly support women to apply.