Hebrew University of Jerusalem (HU) announced a groundbreaking development in the field of optical measurement techniques. Researchers at the university successfully addressed a longstanding challenge in the scientific community: achieving atomic-level precision in the measurement and mapping of the thicknesses of two-dimensional (2D) material flakes. 

July 21, 2023 — Two-dimensional (2D) material flakes have a depth of one to a few atomic layers. This extreme thinness provides them with extraordinary quantum properties which are not observed in everyday materials. As a result, these materials hold immense potential for both industrial applications and advanced research. 

Traditionally, ellipsometry (the measure of change in polarization as light reflects or transmits from a material structure) has been a widely adopted optical technique for noninvasive measurement of thin-film thicknesses. However, commercial ellipsometers face limitations when it comes to measuring areas smaller than 50-60 microns, while 2D flakes often have lateral dimensions of only a few microns. 

Addressing this significant challenge, Prof. Ronen Rapaport and Ph.D. candidate Ralfy Kenaz of the Harvey M. Krueger Family Center for Nanoscience and Nanotechnology, part of the Hebrew University of Jerusalem Faculty of Science’s Racah Institute of Physics, developed and patented a system and method for a microscope-integrated ellipsometer, the Spectroscopic Micro-Ellipsometer (SME). This cutting-edge instrument allows for fast and precise measurements of thin-film thicknesses in extremely small areas, down to a mere 2 microns, within a few seconds. The instrument’s exceptional performance and reliability have already been validated in a separate publication. 

The implications of this research extend to a multitude of industries and research fields that deal with microstructures and pave the way for highly accurate optical investigations of microstructures, opening doors to advancements in technology and scientific exploration. The Spectroscopic Micro-Ellipsometer (SME) is a novel and invaluable system that can be commissioned in the thin-film industry for quality control of wafers, characterizing 2D devices and nanoscale metamaterials and investigating crystal structure of nanoparticles among many other potential applications. 

Prof. Rapaport’s lab is renowned for its expertise in optics experiments. The Rapaport lab collaborated closely with Prof. Hadar Steinberg’s lab, also a part of the Racah Institute of Physics, specializing in 2D materials research. 

You can read more about the SME in this ACS Nano article.