Micro-ellipsometer spectroscopy uncovers atomic level thickness measurements of 2D materials
(Nanowerk News) Two-dimensional (2D) material flakes are composed of one to several layers of atoms, giving it extraordinary quantum properties, which are not observed in everyday materials. As a result, these materials have great potential for advanced industrial and research applications.
Traditionally, ellipsometry has been the widely adopted optical technique for non-invasive measurement of thin film thickness. However, commercial ellipsometers face limitations when it comes to measuring areas smaller than 50-60 microns, whereas 2D flakes often have lateral dimensions of only a few microns.
Responding to this significant challenge, Prof. Ronen Rapaport and Ralfy Kenaz from Hebrew University have developed and patented a system and method for a microscope-integrated ellipsometer, namely the Spectroscopic Micro-Ellipsometer (SME). This state-of-the-art instrument enables fast and precise atomic-level measurement of thin film thickness in very small areas, down to as little as 2 microns in width in a few seconds. The instrument’s excellent performance has been validated in a separate publication, reinforcing its credibility and reliability.
In the most recent publication in the journal ACS nano (“Thickness Mapping and Layer Number Identification of Exfoliated Van der Waals Materials with Fourier Imaging Micro-Ellipsometry”), Hebrew University researchers used this innovative micro-ellipsometer to solve the modern scientific conundrum of measuring and mapping the thickness of atomically thin flakes of 2D material. This finding unequivocally demonstrates the ability of micro-ellipsometers to successfully measure and map the thickness of various flake 2D materials, enabling the determination of their atomic number of layers.
The implications of this research extend to many industries and research fields dealing with microstructures and paved the way for highly accurate micro-optical investigations, opening the door for technological advancement and scientific exploration. By introducing the application of well-established and highly sensitive ellipsometry techniques to microstructures, this research presents a new and invaluable system for researchers and industry.
Spectroscopic Micro-Ellipsometers can be commissioned in the thin film industry for wafer quality control, for characterizing 2D devices and nanoscale metamaterials and investigating the crystal structure of nanoparticles among many other potential applications.
Lab Prof. Ronen Rapaport of the Racah Institute of Physics, known for his expertise in optical experiments, collaborated closely with Prof. Hadar Steinberg, also of the Racah Institute of Physics at Hebrew University, who specializes in 2D materials research.
