Biography
Dimitris Kazazis was born and raised in the island of Lesbos, in Greece. He holds an Electrical and Computer Engineering diploma (2001) from the National Technical University of Athens (NTUA) and a Sc.M. (2005) and Ph.D. (2009) degree from Brown University in Providence, RI, USA (Prof. Alex Zaslavsky's group). He also spent the summers of 2006 and 2007 as a summer intern at IBM T.J. Watson Research Center in Yorktown Heights, NY, USA. Between 2009 and 2014 he was a postdoctoral researcher at the Laboratory for Photonics and Nanostructures in the outskirts of Paris (now Center for Nanoscience and Nanotechnology, Paris-Saclay) and between 2015-2016 he worked on a collaboration between the Laboratory for Photonics and Nanostructures and the Paris Observatory. In 2016 Dimitris Kazazis joined the Laboratory for Micro- and Nanotechnology at PSI as a researcher and project coordinator. Since 2024 he is a tenured scientist in the Laboratory for X-ray nanoscience and technologies. Over the years he has worked and led several projects among which: characterization and modelling of the MOS transistor, ultrathin GeOI conventional and tunneling FETs, epitaxial growth of Ge on high-κ oxides, photocatalysis on thin high-κ oxides, suspended 2DEGs on III-V membranes for thermodynamic and MEMS applications, quantum Hall effect (QHE) in III-V and graphene (notably for metrological applications), state-of-the-art electrical resistance standards based on the QHE in graphene, Schottky diode based THz circuits for space applications, EUV interference lithography and achromatic Talbot lithography. He has taught several classes as a teaching assistant at Brown University (Introduction to Semiconductor and Semiconductor Electronics, Electricity and Magnetism, Analysis and Design of Electronic Circuits) and as part-time lecturer at Paris 7 University (Diderot), between 2013-2016 (undergraduate Physics) and has supervised several undergraduate and graduate students and postdocs.
Institutional Responsibilitites
Member of the Advanced Lithography and Metrology group at PSI. Local coordination of the transnational access of the NFFA-Europe Pilot project at PSI. Responsible for the EUV lithography projects i the group. Supervising the design of the new EUV interference lithography endstation to be commisssioned in 2025 at the XIL-II beamline. Nanofabrication expert in the group, coordinating activities that require advanced micro- and nanofabrication techniques. Supervising and mentoring students and postdocs.
Scientific Research
Dimitris Kazazis' current research lies in the field of nanoscience and nanotechnology. Utilizing and improving advanced nanofabrication techniques especially electron beam lithography (EBL) and extreme UV interference lithography (EUV-IL) he is developing two and three-dimensional structures and devices for applications in plasmonics, microfluidics, nanoelectronics, and x-ray optics. He is also significantly contributing to the ongoing efforts of the Advanced Metrology and Lithography group to improve the EUV-IL technique and its resolution by supervising the design and commissioning of a new EUV-IL endstation. This endstation will contribute to projects requiring single nanometer digit resolution and will significantly contribute to the EUV resist development and chatacterization efforts for future technology nodes using high NA, and hyper NA systems. DK is also a member of a scientific consortium to develop greener photoresists (EU Resin Green project) where he leads the pattern metrology work package.
Selected Publications
For an extensive overview we kindly refer you to our publication repository DORA .
Extreme ultraviolet lithography (EUVL) was recently adopted by the semiconductor industry as the leading-edge lithography technique for continued miniaturization of semiconductor devices in line with Moore’s law. EUVL has emerged as a critical technique, taking advantage of shorter wavelengths to achieve nanoscale feature sizes with higher precision and lower defect rates than previous lithography methods. This Primer comprehensively explores the technical evolution from deep ultraviolet to extreme ultraviolet (EUV) lithography, highlighting innovative approaches in source technology, resist materials and optical systems developed to meet the stringent requirements of high-volume manufacturing. Beginning with an overview of the fundamental principles of photolithography, the main components and functionalities of EUV scanners are described. It also covers exposure tools that support research and early development phases. Key topics — such as image formation, photoresist platforms and pattern transfer — are explained with an emphasis on improving resolution and throughput. Additionally, persistent challenges are addressed, such as stochastic effects and resist sensitivity, with insights provided into future directions for EUVL, including high-numerical aperture systems and novel resist platforms. This Primer aims to present a detailed review of current EUVL capabilities and project the future developments and evolution of EUVL in semiconductor manufacturing.
Extreme ultraviolet (EUV) lithography is the leading lithography technique in CMOS mass production, moving towards the sub-10 nm half-pitch (HP) regime with the ongoing development of the next generation high numerical aperture (high NA) EUV scanners. Hitherto, EUV interference lithography (EUV-IL) utilizing transmission gratings has been a powerful patterning tool for the early development of EUV resists and related processes, playing a key role in exploring and pushing the boundaries of photon-based lithography. However, achieving patterning with HPs well below 10 nm using this method presents significant challenges. In response, this study introduces a novel EUV-IL setup that employs mirror-based technology and circumvents the limitations of diffraction efficiency towards the diffraction limit that is inherent in conventional grating-based approaches. The results are line/space patterning of the HSQ resist down to HP 5 nm using the standard EUV wavelength 13.5 nm, and the compatibility of the tool with shorter wavelengths beyond EUV. Mirror-based interference lithography paves the way towards the ultimate photon-based resolution at EUV wavelengths and beyond. This advancement is vital for scientific and industrial research, addressing the increasingly challenging needs of nanoscience and technology and future technology nodes of CMOS manufacturing in the few-nanometer HP regime.
Atomically precise hydrogen desorption lithography using scanning tunnelling microscopy (STM) has enabled the development of single-atom, quantum-electronic devices on a laboratory scale. Scaling up this technology to mass-produce these devices requires bridging the gap between the precision of STM and the processes used in next-generation semiconductor manufacturing. Here, we demonstrate the ability to remove hydrogen from a monohydride Si(001):H surface using extreme ultraviolet (EUV) light. We quantify the desorption characteristics using various techniques, including STM, X-ray photoelectron spectroscopy (XPS), and photoemission electron microscopy (XPEEM). Our results show that desorption is induced by secondary electrons from valence band excitations, consistent with an exactly solvable non-linear differential equation and compatible with the current 13.5 nm (~92 eV) EUV standard for photolithography; the data imply useful exposure times of order minutes for the 300 W sources characteristic of EUV infrastructure. This is an important step towards the EUV patterning of silicon surfaces without traditional resists, by offering the possibility for parallel processing in the fabrication of classical and quantum devices through deterministic doping.
L.-T. Tseng, P. Karadan, D. Kazazis, P. C. Constantinou, T. J. Z. Stock, N. J, Curson, S. R. Schofield,m M. Muntwiler, G. Aeppli, and Y. Ekinci
Periodic patterning is important for various scientific and technological applications, especially in the nanoscale. Achromatic Talbot lithography (ATL) utilizing extreme ultraviolet (EUV) wavelengths, notably 13.5 nm, is a powerful lithographic technique enabling high-resolution and high-throughput nanopatterning over large areas. Improving the resolution and the throughput of the technique requires elaborate designs based on simulations and nanofabrication of transmission diffraction gratings on thin silicon nitride membranes. Our simulations point to the fact that compared to conventional ATL masks with hole arrays, masks consisting of annular rings and intersecting annular rings show increased performance in terms of throughput. A set of masks with uncrossed and crossed annular rings have been nanofabricated and exposed with spatially coherent synchrotron EUV light and the experimental results confirm our theoretical predictions that masks with annular rings and crossed rings yield dot arrays with improved throughput. The presented technique may enable applications in science and technology where large-area and periodic nanopatterning is needed.
Grayscale electron beam lithography (g-EBL) is a fabrication technique that allows for tunable control of resist topography. In most cases, the height of the structures is in the submicron regime. Here, we present an extensive experimental characterization of the post electron beam exposure behavior of poly(methyl methacrylate) (PMMA) 950 K for grayscale structuring with several micrometers in height. The obtained results show that the development depth for the same electron dose is dependent on the time between exposure and development. This dependence becomes more prominent at higher exposure doses. Additionally, it was found that a post-exposure bake influences the dose-response behavior of the resist material and, therefore, also the obtained three-dimensional (3D) structure. This work paves the way for well-controlled 3D micrometer structuring via g-EBL.
Dynamic tuning of color filters finds numerous applications including displays or image sensors. Plasmonic resonators are subwavelength nanostructures which can tailor the phase, polarization, and amplitude of the optical field, but they are limited in color vibrancy when used as filters. In this work, birefringence-induced colors of plasmonic resonators and a fast switching thin liquid crystal cell are combined in a multicolored electrically tunable filter. With this mechanism, the color gamut of the plasmonic surface and the liquid crystal cell is mutually enhanced in order to generate all primary additive and subtractive colors with high saturation as well as different tones of white. A single filter is able to cover more than 70% of the color gamut of standard RGB filters by applying a voltage ranging between 2 and 6.5 V. This spectral selectivity is added in transmission without any loss in the image resolution. The presented approach is foreseen to be implemented in a variety of devices including miniature sensors or smart-phone cameras to enhance the color information, ultraflat multispectral imagers, wearable or head-worn displays, as well as high resolution display panels.
Books
GeOI as a platform for ultimate devices, W. Van Den Daele, S. Cristoloveanu, E. Augendre, C. Le Royer, J.-F. Damlencourt, D. Kazazis, and A. Zaslavsky in Future Trends in Microelectronics: From Nanophotonics to Sensors and Energy, edited by S. Luryi, J. Xu, and A. Zaslavsky, John Wiley and Sons, Inc., Hoboken, New Jersey (2010)