PhD Position Developing Diffractive Imaging in Scanning Electron Microscopy for Inspection/Metrology

PhD Position Developing Diffractive Imaging in Scanning Electron Microscopy for Inspection/Metrology

Curious about advanced electron microscopy, computational imaging, and nanoscale characterization? Excited to develop the next generation of surface-sensitive diffractive imaging techniques? We’re looking for you!

Job description

As electronic, energy, and bio-inspired devices shrink to the nanoscale, the spatial-resolution requirements and sample-compatibility constraints for materials characterization become increasingly stringent. In particular, the inspection and metrology of advanced semiconductor devices calls for novel techniques capable of handling complex data-streams and analyses — all at high throughput.

Scanning electron microscopy (SEM) is widely used for high-throughput, surface-sensitive characterization of materials and devices. However, its spatial resolution is limited — especially at the low acceleration voltages required for imaging delicate semiconductor structures. Computational diffractive imaging, which reconstructs interpretable signals from indirect detector data, has recently transformed high-resolution imaging in techniques such as scanning transmission electron microscopy (STEM). Yet, it remains largely unexplored at low voltages or in reflection geometries suitable for surface-sensitive studies.

This project aims to bring the power of computational imaging to lower accelerating voltages, such as those used in an SEM, leveraging coherent backscattered (BSE) and incoherent secondary electron (SE) signals to extract nanoscale structural and topographic information. By combining advances in detector technology and source coherence with model-based reconstruction algorithms, we seek to enable surface-sensitive imaging at resolutions beyond what conventional SEM can achieve.

This project is part of the Foundations for Electron-Beam Metrology and Inspection KIC consortium, a collaboration with ARCNL and ASML aimed at advancing fundamental knowledge and technical capabilities in electron beam inspection for the semiconductor industry. In this experimental and computational project, we will explore the simultaneous characterization of bulk and surface-reconstructed structures using the BSE signal, and extract high-resolution topographic contrast from the SE signal. Our first goal will be to identify suitable in-lens, in-chamber, or transmission detector geometries, establishing the coherence requirements and dose-efficiency for each. We will then develop accurate and efficient numerical simulations for BSE and SE image formation at high-resolution, which will form the foundation for our model-based inverse reconstruction algorithms.

The position is in the group of Prof. Georgios Varnavides in the Department of Imaging Physics in close collaboration with KIC consortium partners. We are a newly established computational and experimental imaging lab using electron microscopy techniques and computational imaging to better understand material structure and function. We offer an interactive, supportive, and collegial environment. Our multidisciplinary research spans applied physics, mathematics, materials science, electrical engineering, and optics. We foster frequent interactions through regular group meetings, departmental seminars, and regular exchanges with our experimental collaborators.

Job requirements

We are looking for an outstanding applied physicist with a strong interest in research at the interface of applied physics, mathematics, materials science, and electrical engineering. Relevant research experience in fields such as optics, microscopy, computational science, or applied physics is highly valued.

We especially welcome candidates who:

• Demonstrate high levels of intellectual curiosity.
• Communicate well across disciplinary boundaries.
• Enjoy both theoretical and hands-on experimental work, including instrument development.

We particularly encourage applicants from backgrounds that are traditionally underrepresented in academia to apply.

Applicants must:

• Hold (or be nearing completion of) a Master’s degree in physics, mathematics, materials science, electrical engineering, or a closely related field
• Have excellent written and spoken English communication skills.
• Thrive in an international, multidisciplinary, and collaborative environment.

The following are considered a plus:

• Experience with electron microscopy, quantitative data analysis, and/or numerical modeling.
• Prior hands-on experience modifying or working with scientific instrumentation.

TU Delft (Delft University of Technology)

Delft University of Technology is built on strong foundations. As creators of the world-famous Dutch waterworks and pioneers in biotech, TU Delft is a top international university combining science, engineering and design. It delivers world class results in education, research and innovation to address challenges in the areas of energy, climate, mobility, health and digital society. For generations, our engineers have proven to be entrepreneurial problem-solvers, both in business and in a social context.

At TU Delft we embrace diversity as one of our core values and we actively engage to be a university where you feel at home and can flourish. We value different perspectives and qualities. We believe this makes our work more innovative, the TU Delft community more vibrant and the world more just. Together, we imagine, invent and create solutions using technology to have a positive impact on a global scale. That is why we invite you to apply. Your application will receive fair consideration.

Challenge. Change. Impact!

Faculty Applied Sciences

With more than 1,100 employees, including 150 pioneering principal investigators, as well as a population of about 3,600 passionate students, the Faculty of Applied Sciences is an inspiring scientific ecosystem. Focusing on key enabling technologies, such as quantum- and nanotechnology, photonics, biotechnology, synthetic biology and materials for energy storage and conversion, our faculty aims to provide solutions to important problems of the 21st century. To that end, we educate innovative students in broad Bachelor's and specialist Master's programmes with a strong research component. Our scientists conduct ground-breaking fundamental and applied research in the fields of Life and Health Science & Technology, Nanoscience, Chemical Engineering, Radiation Science & Technology, and Engineering Physics. We are also training the next generation of high school teachers.

Conditions of employment

Doctoral candidates will be offered a 4-year period of employment in principle, but in the form of 2 employment contracts. An initial 1.5 year contract with an official go/no go progress assessment within 15 months. Followed by an additional contract for the remaining 2.5 years assuming everything goes well and performance requirements are met.

Salary and benefits are in accordance with the Collective Labour Agreement for Dutch Universities, increasing from € 2901 per month in the first year to € 3707 in the fourth year. As a PhD candidate you will be enrolled in the TU Delft Graduate School. The TU Delft Graduate School provides an inspiring research environment with an excellent team of supervisors, academic staff and a mentor. The Doctoral Education Programme is aimed at developing your transferable, discipline-related and research skills.

The TU Delft offers a customisable compensation package, discounts on health insurance, and a monthly work costs contribution. Flexible work schedules can be arranged.

Will you need to relocate to the Netherlands for this job? TU Delft is committed to make your move as smooth as possible! The HR unit, Coming to Delft Service, offers information on their website to help you prepare your relocation. In addition, Coming to Delft Service organises events to help you settle in the Netherlands, and expand your (social) network in Delft. A Dual Career Programme is available, to support your accompanying partner with their job search in the Netherlands.

Additional information
If you would like more information about this vacancy or the selection procedure, please contact Prof. Georgios Varnavides, via gvarnavides@berkeley.edu