MESA+ University of Twente
Industrial focus group XUV Optics


Post Doc Position – Science and Technology


Ultrathin films of nanoscale thickness find a major application in multilayer reflective optics. When designed for the Extreme UV wavelength range, multilayers have enabled the sensational development of a high-resolution lithographic technology for the manufacture of integrated circuits. Yet this technique shows a challenge for optics development: tenth-nanometer precision is required for the optics’ accuracy and positioning, while, at the same time, kilowatt-power EUV light sources cause tremendous thermal loads on these optics, leading to distortions of the fine imaging process. A solution to this challenge is to add adaptive optical functionality. In a pilot project the first exploration of adapting surface figures and spectral functionality has successfully been executed. Based on this assessment a new multilayer composition is proposed, including piezo-electrical layers that allow to interactively manipulate the periodic Bragg structure. Steering such control layers by external electrical signals will then allow wavefront corrections and localized optical changes with precision down to the tenth-nanometer range. The goal of this new project is to develop the knowledge for such adaptive optics.

Job specification

The work involves preparation of thin films by sputtering techniques and pulsed laser deposition and a study of their electrical, optical and structural properties. The goal is to combine thin layers with different atomic arrangement: layers with amorphous (EUV multilayer), crystalline and polycrystalline (piezo-electric layer) structures with certain properties. This will be implemented by growing different regions of the multilayer structure under different conditions, including energy of the deposited particles and thermal regimes. This will be done in a newly built setup that allows deposition at substrate of variable temperature, and tunable energy of deposited particles. The growth will be simultaneously assisted by low energy ion bombardment. A trade-off between the structural disordering due to the ballistic effects of the ions and favorable adatom migration will be investigated. Lastly, the use of thin crystalline membranes (nano-sheets) will be explored as a template for ordered layer growth. The research is done in close collaboration with other industrial and academic parties, including Carl Zeiss SMT, ASML, PANalytical, DEMCON, SolMateS, TNO, and various research institutes.

Your profile

We are looking for a PostDoc who is a skilled experimentalist with PhD degree in physics, materials science, physical chemistry or engineering. Experience with deposition of thin films and their analysis is considered advantageous. Our favored candidates are creative and like to push boundaries. We expect the candidate to have excellent command of the English language as well as professional communication and presentation skills.

For further information you can contact Prof. Fred Bijkerk at, +31 620573555, +31-53-4894885/2130.

Candidates are invited to upload their application at the UT web address, including a short motivation letter, references, and CV to the application button below.