ER-C’s Electron Microscope Receives Unique Upgrades

Forschungszentrum Jülich operates some of the most powerful electron microscopes in Europe at the Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C), in part together with RWTH Aachen University. The instruments not only make it possible to study the structure and composition of materials with sub-Ångstrom spatial resolution, but also to determine their local functional properties.

Such capabilities are essential for the development of innovative new materials, such as those needed for information and energy technology. In cooperation with partners from science and industry, including the Swiss company Attolight AG, a project is now underway to install ground-breaking upgrades to one of the electron microscopes in the ER-C. These upgrades are intended to allow nanoscale magnetic structures and their dynamics to be analyzed under light illumination with unprecedented spatial resolution. The project is funded through the ERC Synergy Grant “3D MAGIC” of the European Research Council. The aim of 3D MAGIC is to study still largely unknown nanoscale magnetic structures that have particle-like properties and whose existence has so far only been predicted theoretically.

A prototype ultra-high-resolution aberration corrected electron microscope was developed in the 1990s in collaboration with Jülich, and is still on site at the ER-C today. Since then, the need for ever more sophisticated analysis has driven further technical and methodological developments in Jülich, often in cooperation with industry. Another important stage is now beginning: Forschungszentrum Jülich has signed a contract with the company Attolight AG to order customized components for a unique upgrade of its Titan “Holo” microscope.

From 2022, this upgrade will enable the study of light-matter interactions with unprecedented spatial resolution. A strong focus of the project involves the study of 3D magnetic solitons, which are extremely puzzling and challenging research objects that range from a few nanometres to a few hundred nanometres in size, only occur in certain magnetic materials and offer prospects for new types of information storage for so-called neuromorphic computing - energy-efficient computing modelled on the human brain.

 

- Researchers are looking to study magnetic nanostructures that are termed “hopfions”.

Copyright: Forschungszentrum Jülich

 

At the ER-C, off-axis electron holography is being used to measure the magnetic fields of nanostructures with high spatial resolution. The technique is based on the interference of two electron beams and allows the recovery of the electron optical phase shift of the electrons. The technique provides direct and quantitative information about magnetic fields in materials on the nanometre scale. The new instrumentation aims to make it possible to apply external magnetic fields, temperature gradients and electrical currents, in combination with laser illumination, to a sample inside the electron microscope.

At the core of the upgrade is a light injection system (Mönch) manufactured by Attolight. This add-on enables light to be injected into the electron microscope by focusing a laser beam onto a specimen with a very small spot size (below 2 µm in diameter). The system offers both light injection and collection for wavelengths ranging from the ultraviolet to the infrared. In this project, the light source will be used to carry out dynamic measurements of the magnetic properties of materials in the sub-µm range.

The concept for the upgrade was developed at Forschungszentrum Jülich. Several other institutes in Jülich are involved in the project, including PGI-1, PGI-6 and the Central Institute of Engineering, Electronics and Analytics (ZEA), as well as companies that will supply lasers, special magnetic coils, sample holders and software for automation of experimental workflows. Scientists in the ER-C are among a small number of experts worldwide able to image magnetic structures that are just a few nanometres in size. Attolight is extremely proud to participate in the upgrade of the Titan Holo microscope in Jülich and to contribute to the achievement of new breakthroughs in the field of magnetic imaging.

The Titan Holo microscope at Forschungszentrum Jülich stands taller than an average person. From 2022 onwards, after the planned upgrades, it will be possible to apply local magnetic fields, electrical currents and optical stimuli in this microscope to study the magnetic properties of nanoscale materials at cryogenic temperatures.
Copyright: Forschungszentrum Jülich

 

Further information:

Press release from Forschungszentrum Jülich “ERC Synergy Grant: 12 Million Euros for research into “magic” 3D nanostructures” from 11.10.2019


International Conference on Display Technology

Attolight as invited speaker at ICDT  2021 

Attolight will attend the 2021 Edition of ICDT (International Conference on Display Technology) from May 30 to June 2, 2021This ). ICDT is the only display technology conference held solely by SID outside the United States. The event gathers top scientists, engineers, corporate researchers, and business people of the display industry.  

Our Head of Industry Applications, Matthew Davies will give a talk during the session ‘Micro LED Applications. 

We welcome you to attend his presentation on ‘An Alternative Method for Cost Effective Probing in MicroLEDs’ on Wednesday, June 2/15:40 (Session 53.1). 

For more information on the conference: https://www.sidicdt.org/en/  

Full program of the conference: https://www.sidicdt.org/en/col.jsp?id=165 


SEMICON Europa 2021

Fell free to visit our German representative Merconics (booth B1650) during the Semicon Europa 2021 (Munchen-Germany, Nov 16-19, 2021).

Conference website: https://www.semiconeuropa.org/

Agenda : https://www.semiconeuropa.org/programs-catalog/agenda-at-a-glance 


CS International Conference 2021

Attolight presentation on Cost-Effective Probing in High Volume Manufacturing of MicroLEDs 

Attolight will attend the 2021 Edition of CS International from November 9th - November 10th 2021

Our CEO, Samuel Sonderegger will give a talk during the session Seeking new opportunities for LEDs and lasers on Tuesday, November 9th.

Drop by our booth to learn more about our cathodoluminescence R&D and metrology solutions.

For more information on the conference: https://csinternational.net/

Full program of the conference: https://csinternational.net/agenda


Meet us at CS International 2022 (June 28-29, Brussels)

Attolight presentation on Cost-Effective Probing in High Volume Manufacturing of MicroLEDs 

Attolight is pleased to invite you to the 2022 Edition of CS International on June 28-29, 2022 (Brussels, Belgium) and the talk (June 29th, 14:05) on Cost-Effective Probing in High Volume Manufacturing of MicroLEDs given by Samuel Sonderegger

For more information on the conference: https://csinternational.net/

Full program of the conference: https://csinternational.net/agenda


Attolight as invited speaker at Display Week 2021

Attolight will attend the 2021 Virtual Edition of Display Week (May 17-21, 2021) that will gather the international specialists of OLED, MicroLED, AR/VR/MR, printed displays. This event includes the most influential companies in the business of display. In this frame, our Head of Industry Applications, Matthew Davies, is invited to give a talk during the session ‘Micro LED Display Metrology’.

We welcome you to attend his presentation on ‘Cost Effective Probing in High Volume Manufacture of µLEDs’ on Thursday, May 20th afternoon (Session 58.2).

For more information on the conference: http://www.displayweek.org/

Full program of the conference: http://www.displayweek.org/Portals/5/pdf/2021%20Preliminary%20Program.pdf

  

Abstract

Cost Effective Probing in High Volume Manufacture of µLEDs

Matthew Davies, Attolight AG-Switzerland 

Cost-effective probing of µLEDs in mass-production presents a new series of challenges associated with the greatly increased quantity and density of devices per wafer, specifically regarding measurement time, spatial resolution, and wafer throughput.  Here we present a cost appropriate probing solution for wafer level metrology of µLEDs, specifically designed to address the need for post-frontend device verification.

 


A Novel Technique to Probe Optical Absorption of 2D Materials by Cathodoluminescence

Nano Letters  has recently reported a novel technique to map the optical absorption of two-dimensional materials. It is a non-contact and non-destructive technique named Quantitative Nanoscale Absorption Mapping (QNAM). The inventors of QNAM come from EPFL (Lausanne, Switzerland), IMEM (Parma, Italy), the U.S. Army (New Jersey, USA) and the Instituto Nanoscienze (Pisa, Italy).

How does it work?

The original approach of QNAM is to probe the absorption properties of a 2D material using the CL emission of the underlying substrate as the light source.

Sketch of the working principle of QNAM

A bulk substrate topped with a two-dimensional layer is excited by an electron beam. As a result, the substrate emits light, via a cathodoluminescence process, that is partially absorbed by the 2D material.

What does it bring?

In their report, the authors first noticed an enhancement of the absorption in the UV range due to interlayer excitonic phenomena. Then, they extended the QNAM technique to measure the optical absorption of MoS2/MoSe2 van der Waals heterostructures. Finally, they used it to detect defects such as grain boundaries and ad-layers.

(a, b, c) MoS2 ML on sapphire substrate (d, e, f) MoSe2 flake on Al2O3. (a, d) Secondary electron image. (b, e) QNAM map. (c, f) CL spectra.

To find out more on the QNAM technique

Quantitative Nanoscale Absorption Mapping: A Novel Technique To Probe Optical Absorption of Two-Dimensional Materials, M.Negri, L.Francaviglia, D.Dumcenco, M.Bosi, D.Kaplan, V.Swaminathan, G.Salviati, A.Kis, F.Fabbri, A.Fontcuberta i Morral, Nano Lett. 2020, 20, 1, 567-576


Publication in Science : Cathodoluminescence of nanoparticles

The Mönch (https://attolight.com/monch/) is a unique add-on designed to collect or inject light in STEM. In a paper just released in Science, the capability of Mönch to detect luminescence from nanoscale isolated grains demonstrates the collection efficiency on low-emitted samples. This unique feature is due to a large numerical aperture but also to a very short working distance which allows to optimize the optical collection efficiency.

Lightening based on LED (light emitting diodes) has lead to a substantial decrease in energy consumption due to their increased efficiency compared to incandescent bulbs. This was made possible by the development and improvement of new materials in the 1990s, specifically the III-N semiconductor family. Still, much can be gained by the discovery of novel materials, including the improvement of mechanical properties. Recently, lead halide perovskites (LHPs) with composition CsPbX3 (X a halide, such as I, Cl, Br) have attracted intensive focus from the scientific community due to technological advances in the areas of photovoltaics, LEDs, radiation detection, and thermometry. A key limit for their application is their long-term stability and production with the required crystal structure (which controls their electronic and optical behaviour).

In an article published in Science (DOI: 10.1126/science.abf4460), Jingwei Hou (University of Queensland, UQ, Australia) and collaborators report on a new class of composites made of LHPs nanoparticles embedded and protected by metal organic frameworks (MOFs). As the composite contains nanoscale particles, microscopic techniques are needed to identify particles and demonstrate if they are behind the light emission process.

This composite produces bright and efficient photoluminescence (Figure 1). Nanometer scale electron diffraction and spectroscopy showed that indeed CsPbX3 occurred as nanoparticles in the composite (Figure 1). Using Cathodoluminescence at the LPS-CNRS in a scanning transmission electron microscope (ChromaTEM Microscope of the TEMPOS project) equipped with the Attolight Mönch system, the collaboration showed strong luminescence (image bottom left) detected from isolated grains (<40 nm). The light spectrum of the composite (image bottom right) is sharp, which translates to very small interparticle emission wavelength variation.

The findings will enable the manufacture of glass screens that show improved mechanical strength but also deliver crystal clear image quality. Its discovery is a huge step forward in perovskite nanocrystal technology as previously, researchers were only able to produce this technology in the bone-dry atmosphere of a laboratory setting, as the perovskites themselves are extremely sensitive to ambient conditions, including exposure to air, humidity, and light.

Caption: Hybrid lead halid perovskites and metal-organic framework composites show remarkable stability and light emission efficiency (upper left). Nanoscale electron diffraction in a Scanning Transmission Electron Microscope (STEM) allows one to identify the phase of individual CsPbX3 nanocrystals (upper right). Finally, cathodoluminescence (CL) on a STEM demonstrates that light stems from individual nanocrystals (bottom lefet), all with very similar emission spectrum (bottom right).

Reference: Jingwei Hou, et al., Science, 374 6567 (2021).


Cambridge University - Grand Opening

On September 12th, 2019, the Department of Materials Science & Metallurgy of Cambridge University held a Grand Opening Ceremony for their brand-new Allalin Chronos tool.

Prof Rachel Oliver and her team gathered more than 50 researchers from the UK scientific and industrial community, to officially introduce this new tool, funded through an Engineering and Physical Sciences Research Council (EPSRC) grant.

The day started with the official opening ceremony by Prof Lindsay Greer (Head of the School of Physical Sciences), then went on with many talks about the first Cathodoluminescence results obtained on the tool. The results encompassed materials ranging from compound semiconductor materials and devices to perovskite and geological samples, hinting at promising publications to come.
Prof Rachel Oliver followed with the practicalities of access to the tool, which is a shared facility for the UK scientific community.

Attolight warmly thanks Prof Rachel Oliver and her team for their hospitality and the organisation of this great event !

 


Focus on CL in the Compound Semiconductor Magazine!

With the launch of the Säntis 300 by Attolight, Cathodoluminescence is going to revolutionize the quality control of semi-conductor devices by enabling a quick and non-invasive way to determining alloy compositions, exposing and buried defects and uncovering surface contamination.

Find out the full article about ‘Quantitative cathodoluminescence streamlines chip production’, published in the last issue of Compound Semiconductor Magazine of June 2019.