PhD-student: In semiconductor manufacturing technology advanced metrology to inspect the quality of devices as they are manufactured is crucial. You will develop a new paradigm for metrology on the interface of three research fields: metasurfaces, wavefront shaping and computational imaging.

The tremendous success of the semiconductor industry has become possible due to highly advanced optical nanolithography to define smaller and smaller nanostructures, hand in hand with quick and accurate optical methods for metrology and inspection. Such metrology methods inspect devices during manufacturing to ensure absence of defects and compliance with very tight tolerances in terms of dimensions and relative alignment of device components. In current day wafer metrology techniques, wafers are often designed to have dedicated target patterns that scatter light and reveal fine positional and dimensional information. Optical detection techniques include both real space imaging and measurement of diffraction patterns to retrieve the desired metrological information.

Optical metrology hinges on three basic ingredients. First, a designer scattering target encodes the positional or dimensional dependence of interest. Next, for a given target structure an intriguing question is what state of light one should offer as illumination to provide the best measurement precision. Finally, one should also ask what read-out strategy provides the best measurement precision. At the state of the art each of these questions is addressed separately. For instance, in terms of structures, metasurfaces are thin nanostructured layers with engineered resonances in their constituent dielectric or metallic nanoparticles designed so that under simple illumination their geometry translates into a geometry-dependent diffraction pattern. Conversely, advanced wavefront shaping allows to create illumination patterns that exactly match scattering properties of the object. Finally, computational imaging specializes in extracting the most information from optical data through optical read-out design and algorithms for post-processing.

In this project, we will explore the new paradigm of co-designing all three aspects simultaneously, which we coin end-to-end optimized nanophotonic metasurface-based computational metrology. You will work with modern numerical optimization methods to co-design photonic nanostructures, illuminations, and detection schemes. Next, you will implement your ideas in experiments: at AMOLF you will fabricate nanophotonic structures and you will use the ARCNL expertise in wavefront shaping together with recently developed imaging techniques to explore ultimate measurement precision. We expect to uncover new fundamental limits to the use of nanostructures for optical metrology, and to realize prototype experiments that demonstrate practical relevance.

You will perform this project in the research group Resonant Nanophotonics at AMOLF and the Nanoscale Imaging and Metrology group of Lyuba Amitonova at ARCNL. The research will be done in close collaboration with ASML, and targets both academic and applied breakthroughs.

We are looking for an enthusiastic candidate with an MSc or equivalent degree in physics or a strongly related field. A background in optics and nanophotonics, diffraction or microscopy based methods, and/or computational imaging is a clear advantage. Affinity for performing optical experiments, solving mathematical problems, large-scale optimization techniques, and working as part of a team are considered important.Candidates should have experimental skills and be able to communicate in English. The project’s results will be presented at national and international conferences and in relevant journals. The successful candidate is expected to write a PhD thesis towards the end of the 4-year project, which will be defended at the University of Amsterdam. You will need to meet the requirements for an MSc-degree, to ensure eligibility for a Dutch PhD examination.

The position is intended as full-time (40 hours / week, 12 months / year) appointment in the service of the Netherlands Foundation of Scientific Research Institutes (NWO-I) for the duration of four years, with a starting salary of gross € 2,441 per month and a range of employment benefits. After successful completion of the PhD research a PhD degree will be granted at University of Amsterdam. Several courses are offered, specially developed for PhD-students. AMOLF assists any new foreign PhD-student with housing and visa applications and compensates their transport costs and furnishing expenses.

Nanoscale Imaging and Metrology

This is a collaborative project between the Resonant Nanophotonics group at AMOLF, headed by Prof. Dr. Femius Koenderink and the Metrology Department at ARCNL, in particular with Dr. Lyuba Amitonova. The research activities in the Resonant Nanophotonics group at AMOLF aim at developing nanoscale photonic structures, such as plasmonics and metasurfaces, to control scattering, emission, amplification and detection of light. The group spans the entire research cycle from developing advanced nanophotonics concepts using state of the art theory and numerical design, to nanofabrication of designed structures in the Amsterdam NanoLab cleanroom at AMOLF, and the development of state of the art optical scatterometry and microscopy methods. The ARCNL team is expert in wavefront shaping and complex scattering media for imaging and metrology. For this project, your lab work will be primarily stationed at AMOLF. As researcher in the AMOLF-ARCNL joint research programme, you will work closely with the ARCNL team, as well as with expert industrial contacts from ASML.

AMOLF performs leading research on the fundamental physics and design principles of natural and man-made complex matter, with research in 4 interconnected themes: nanophotonics, nanophotovoltaics, designer matter, and biophysics. AMOLF leverages these insights to create novel functional materials, and to find solutions to societal challenges in renewable energy, green ICT, and health care. AMOLF is one of the NWO-I national research institutes located at the Amsterdam Science Park, Amsterdam, The Netherlands. It has approximately 130 scientist and a total size of ca. 200 employees. Furthermore it hosts the Amsterdam NanolabNL clean room, which is part of the national NanoLabNL cleanroom network. See also www.amolf.nl

 ARCNL The Advanced Research Center for Nanolithography (ARCNL) focuses on the fundamental physics and chemistry involved in current and future key technologies in nanolithography, primarily for the semiconductor industry. ARCNL is a public-private partnership between the Dutch Research Council (NWO), the University of Amsterdam (UvA), the VU University Amsterdam (VU) and the semiconductor equipment manufacturer ASML. ARCNL is located at the Amsterdam Science Park, Amsterdam, The Netherlands, and is currently building up towards a size of approximately 100 scientists and support staff. See also www.arcnl.nl