microelectronics – Lightsources.org

Argonne celebrates successful completion of the APS Upgrade

2026/02/052026/02/10

The U.S. Department of Energy has granted its final approval to the project, bringing the decade-plus-long effort to a close

The upgraded APS is now the brightest synchrotron X-ray light source in the world, and extraordinary new scientific experiments are underway.

The comprehensive upgrade of the Advanced Photon Source (APS) is officially completed.

The U.S. Department of Energy (DOE) has given its final approval to the APS Upgrade Project, an $815 million effort to transform the APS into the brightest synchrotron X-ray facility in the world. The effort has taken more than a decade to plan and complete and has resulted in a facility with unprecedented capabilities for scientific discovery. The APS is a DOE Office of Science user facility at DOE’s Argonne National Laboratory.

The upgraded APS now generates X-ray beams that are up to 500 times brighter than before and sports nine new experiment stations (called beamlines) built to take full advantage of those enhanced beams. Scientists have been using the revamped facility for more than a year, exploring its new capabilities for research into more durable materials (for airplane turbines and other high-stress uses), longer-lasting batteries (for laptops and cell phones) and microelectronics (for our device-driven modern lives).

Read more on the Argonne website

Image: Advanced Photon Source

Credit: Argonne National Laboratory

Metastable marvel: X-rays illuminate an exotic material transformation

2025/01/162025/01/20

A flash of light traps this material in an excited state indefinitely, and new experiments reveal how it happens.

A dry material makes a great fire starter, and a soft material lends itself to a sweater. Batteries require materials that can store lots of energy, and microchips need components that can turn the flow of electricity on and off.

Each material’s properties are a result of what’s happening internally. The structure of a material’s atomic scaffolding can take many forms and is often a complex combination of competing patterns. This atomic and electronic landscape determines how a material will interact with the rest of the world, including other materials, electric and magnetic fields, and light.

Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory, as part of a multi-institutional team of universities and national laboratories, are investigating a material with a highly unusual structure — one that changes dramatically when exposed to an ultrafast pulse of light from a laser.

“Together, these complementary facilities are accelerating our understanding of metastable state creation.” — Argonne Physicist Haidan Wen

After the pulse, the material is caught in an exotic state outside of equilibrium, or stability. Called metastable, these states are an exciting and largely unexplored phenomenon in materials science, and they could find application in information storage and processing.

The team of scientists created the metastable state in 2019 and characterized the material before and after its transition. Using a combination of advanced X-ray and ultrafast laser capabilities, their recent experiments reveal the evolution of the material’s structure during the transition. The researchers captured the entire process in detail across several orders of magnitude in time, ranging from the picosecond to microsecond scales (trillionths to millionths of a second).

In particular, the team is investigating metastability in a class of materials called ferroelectrics, which play an important role in sensing and memory applications. Understanding these transitions in ferroelectrics could eventually inform the design of materials for next-generation microelectronics.

Metastable states

“Most of the materials used in technology are in equilibrium — or their lowest energy state — so that a technology can work reliably without wild variations in performance,” said Venkatraman Gopalan, professor at Pennsylvania State University and an author on the study. “However, this is very restrictive, since amazing properties may lurk just beyond equilibrium.”

The challenge is that nonequilibrium states are generally short-lived. Metastable states, however, are nonequilibrium states that persist for a very long time. Diamond, for example, is a metastable state of carbon. We say they’re forever, but over the course of billions of years, diamonds decay into graphite, a more stable state of carbon.

“It’s sort of like throwing a ball up a cliff, and instead of it returning to the ground, the ball gets stuck on a ledge on the cliff wall,” Gopalan said. If the pathway to the ground is blocked by the ledge, the ball will rest there in a metastable state.

The scientists created the starting phase in this experiment by combining alternating layers of two materials — a ferroelectric and a nonferroelectric. The configurations of the electrons within the different layers compete with each other, resulting in a swirling pattern of vortices in the electronic structure across the material. This internal frustration blocks pathways that the material might otherwise take to return to equilibrium after being excited by the laser pulse.

Read more on Argonne website

Image: Illustration of the material’s transition, with time represented from left to right. A laser pulse (left) sends the material into disorder (middle). Out of this so-called soup phase emerges a highly ordered phase called a supercrystal (right).

Credit: Argonne National Laboratory

Leap toward more energy-efficient supercomputing

2024/10/162024/10/17

Researchers have revealed an adaptive response with a ferroelectric device, which responds to light pulses in a way that resembles the plasticity of neural networks. This behavior could find application in energy-efficient microelectronics.

“Today’s supercomputers and data centers demand many megawatts of power,” said Haidan Wen, a physicist at the U.S. Department of Energy (DOE) Argonne National Laboratory. “One challenge is to find materials for more energy-efficient microelectronics. A promising candidate is a ferroelectric material that can be used for artificial neural networks as a component in energy-efficient microelectronics.”

Ferroelectric materials can be found in different kinds of information processing devices, such as computer memory, transistors, sensors and actuators. Argonne researchers report surprising adaptive behavior in a ferroelectric material that can evolve step-by-step to a desired end, depending on the amount of photons from light pulses striking the material. Working alongside Argonne researchers were scientists from Rice University, Pennsylvania State University and DOE’s Lawrence Berkeley National Laboratory.

This team’s material is laden with networked islands or domains that are as distinct as oil in water. These domains are nanometers in size — billionths of a meter — and can rearrange themselves in response to light pulses. This adaptive behavior could be used in the energy-efficient movement of information in microelectronics.

The team’s ferroelectric sample is structured as a sandwich of alternating layers of lead and strontium titanate. Prepared by the Rice University collaborators, this seven-layer sandwich is 1,000 times thinner than a piece of paper. Previously, the team had shined a single, intense light pulse on a sample and created uniform, nanoscale ordered structures.

“Today’s supercomputers and data centers demand many megawatts of power. One challenge is to find materials for more energy-efficient microelectronics. A promising candidate is ferroelectric material that can be used for artificial neural networks as a component in energy-efficient microelectronics.” — Haidan Wen, Argonne physicist

“This time, we hit the sample with many weak light pulses, each of which lasts a quadrillionth of a second,” Wen said. “As a result, a family of domain structures, rather than a single structure, was created and imaged, depending on the optical dosage.”

To visualize the nanoscale responses, the team called upon the Nanoprobe (beamline 26-ID) operated by the Center for Nanoscale Materials and the Advanced Photon Source (APS). Both are DOE Office of Science user facilities at Argonne. With the Nanoprobe, an X-ray beam tens of nanometers in diameter scanned the sample as it was exposed to a barrage of ultrafast light pulses.

The resulting images revealed networked nanodomains being created, erased and reconfigured due to the light pulses. The regions and boundaries of these domains evolved and rearranged at lengths of 10 nanometers — about 10,000 times smaller than a human hair — to 10 micrometers, roughly the size of a cloud droplet. The final product depended on the number of light pulses used to stimulate the sample.

“By coupling an ultrafast laser to the Nanoprobe beamline, we can initiate and control changes to the networked nanodomains by means of light pulses without requiring much energy,” said Martin Holt, an X-ray and electron microscopy scientist and group leader.

Read more on APS website

Image: Artistic rendering representing light pulses yielding adaptive transformations in nanodomain structures applicable to neuromorphic computing.

Credit: Argonne National Laboratory/Haidan Wen.

Machine learning enhances X-ray imaging of nanotextures

2023/07/152023/08/14

Using a combination of high-powered X-rays, phase-retrieval algorithms and machine learning, Cornell researchers revealed the intricate nanotextures in thin-film materials, offering scientists a new, streamlined approach to analyzing potential candidates for quantum computing and microelectronics, among other applications.

Scientists are especially interested in nanotextures that are distributed non-uniformly throughout a thin film because they can give the material novel properties. The most effective way to study the nanotextures is to visualize them directly, a challenge that typically requires complex electron microscopy and does not preserve the sample.

The new imaging technique detailed July 6 in the Proceedings of the National Academy of Sciences overcomes these challenges by using phase retrieval and machine learning to invert conventionally-collected X-ray diffraction data – such as that produced at the Cornell High Energy Synchrotron Source, where data for the study was collected – into real-space visualization of the material at the nanoscale.

The use of X-ray diffraction makes the technique more accessible to scientists and allows for imaging a larger portion of the sample, said Andrej Singer, assistant professor of materials science and engineering and David Croll Sesquicentennial Faculty Fellow in Cornell Engineering, who led the research with doctoral student Ziming Shao.

“Imaging a large area is important because it represents the true state of the material,” Singer said. “The nanotexture measured by a local probe could depend on the choice of the probed spot.”

Read more on the CHESS website

Multilayer stack opens door to low-power electronics

2022/08/292022/09/01

Researchers found that a stack of ultrathin materials, characterized in part at the Advanced Light Source (ALS), exhibits a phenomenon called negative capacitance, which reduces the voltage required for transistor operation.

The material is fully compatible with today’s silicon-based technology and is capable of reducing power consumption without sacrificing transistor size or performance.

High efficiency, low disruption

Microelectronics is expected to account for about 5% of total electricity production by 2030 thanks to ever-increasing demands for information processing. Maintaining progress will require a fundamental shift toward more efficient devices, with an emphasis on materials compatible with state-of-the-art silicon technology.

The phenomenon of negative capacitance represents one possible solution, promising to significantly reduce power consumption in electronic devices while fitting seamlessly into current semiconductor protocols. In this work, researchers took a key step toward integrating negative capacitance into advanced transistors, with support from various government and industrial groups including Samsung, Intel, SK hynix, Applied Materials, and DARPA.

Inside the gate

A transistor is essentially an on-off switch for the flow of current through a semiconductor, activated by a small voltage from a “gate” electrode. A thin insulating layer (the gate oxide) separates the semiconductor from the gate. Increasing the gate oxide’s ability to store charge (i.e., its capacitance) lowers the transistor’s operating voltage and thus reduces overall power consumption.

In advanced silicon transistors, the gate oxide is a combination of silicon oxide (SiO₂) and hafnium oxide (HfO₂). In this work, researchers replaced the HfO₂ with a multilayered stack that displays negative capacitance—a counterintuitive effect in which decreasing the gate voltage increases the stored charge on the gate oxide, thus maintaining performance at reduced power.

Read more on the Berkeley Laboratory website

Image: Artistic rendering of a multilayered structure that exhibits negative capacitance, integrated onto a silicon chip. Incorporating this material into advanced silicon transistors could make devices more energy efficient.

Credit: Ella Maru Studio/UC Berkeley

NSLS-II Researchers Win 2022 Microscopy Today Innovation Award

2022/08/232022/08/25

The team developed a set of bonded x-ray lenses to overcome a long-standing alignment issue, making nanometer resolution more accessible than ever before.

Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory received the 2022 Microscopy Today Innovation Award for their development of a system with bonded x-ray lenses that make nanoscale resolution more accessible than ever before. When the team at the National Synchrotron Light Source II (NSLS-II), a DOE Office of Science user facility, tested the new lens system, they achieved a resolution down to approx. 10 nanometers.

“We need technologies of the future to tackle some of society’s biggest challenges — from microelectronics to tiny qubits for quantum computers to longer-lasting batteries,” said John Hill, NSLS-II Director. “However, to develop these new devices, researchers need to study materials at the nanoscale. And this where these new lenses really come into their own. They make focusing hard x-ray beams down to a few nanometers much easier than ever before. By using the very focused x-ray beams that these lenses produce, we can reveal the function, structure, and chemistry of next-generation materials on the nanoscale. This crucial breakthrough was only made possible through years of intense work by experts—who are world-leaders in their respective fields—working together. I am delighted that their work has been recognized by this award and very proud to have this new lens system at NSLS-II.”

Read more on the Brookhaven National Laboratory website

Image: The members of the development team in front of NSLS-II. From left to right: Yong Chu, Hanfei Yan, Weihe Xu, Wei Xu, Xiaojing Huang, Ming Lu, Natalie Bouet, Evgeny Nazaretski. Not pictured: Juan Zhou and Maxim Zalalutdinov.

Microscopic origins of electrical conductivity in superheated solids revealed

2021/04/022021/04/15

Scientists used terahertz radiation for measurements of strongly excited material

In-depth understanding of the electrical conductivity of matter is the key to many cutting-edge research and applications, ranging from phase-change memory in microelectronics to magnetospheres rooted in planetary interiors due to the motion of the conductive fluid. Unique states of material created by ultrafast table-top lasers or free-electron lasers (FEL) allow us to gain insight into atomic levels. However, it also requires sub-picosecond resolution to capture the details on the timescale of atomic motion. Therefore, in conductivity measurements it prevents the use of contact diagnostics such as multimeter and four-point-probe. Although ultrafast optical or X-ray measurements can provide information on high frequency electrical conductivity, they require complex models to extrapolate the intrinsic direct current (DC) conductivity of material.

The terahertz radiation (1 THz= 10¹²Hz (cycles per second)) offers a unique solution to tackle this dilemma. The THz electromagnetic wave behaves like DC electric-field to the sample because the oscillation of its electric field is slow compared to the electron momentum relaxation frequencies in solid and liquid materials (typically 10¹³Hz or larger), and the width of each THz cycle is short enough to resolve sub-picosecond dynamics. Nevertheless, to measure the conductivity of strongly excited materials in the irreversible regime still requires high brightness THz radiation in order to penetrate the dense electron cloud as well as high sensitivity to detect the THz temporal profile in a single shot.

An international research team, led by scientists from the SLAC National Accelerator Laboratory and DESY, have recently measured the electrical conductivity of strongly heated material using the THz FEL radiation at FLASH. In this study, gold nano-foil samples were heated by the FLASH extreme ultraviolet (XUV) FEL pulses to electron temperatures up to 16,000 °C. As the thermal energy transfers from the electrons to the ions, the sample transits from cold to superheated solid and eventually melts into warm dense liquid. The researchers have determined the DC electrical conductivity by measuring the transmitted THz electric field through the heated samples. The multi-cycle THz pulses from FLASH provide continuous measurements with temporal resolutions better than 500 femtoseconds.

IBM Investigates Microelectronics at NSLS-II

2020/10/262020/11/01

IBM researchers used the Hard X-ray Nanoprobe at NSLS-II to visualize strain in a new architecture for next-generation microelectronics

From smartphones to laptops, the demand for smaller and faster electronics is ever increasing. And as more everyday activities move to virtual formats, making consumer electronics more powerful and widely available is more important than ever.

IBM is one company at the forefront of this movement, researching ways to shrink and redesign their microelectronics—the transistors and other semiconductor devices that make up the small but mighty chips at the heart of all consumer electronics.

“As devices get smaller, it becomes more challenging to maintain electrostatic control,” said Conal Murray, a scientist at IBM’s T.J. Watson Research Center. “To ensure we can deliver the same level of performance in smaller devices, we’ve been employing new semiconductor materials and designs over the last decade.”

Read more on the NSLS-II website

Image: NSLS-II scientist Hanfei Yam is shown at the Hard X-ray Nanoprobe beamline, where IBM researchers visualised strain in a new architecture for next-generation microelectronics.

Enhancing Materials for Hi-Res Patterning to Advance Microelectronics

2019/08/272019/08/28

Scientists at Brookhaven Lab’s Center for Functional Nanomaterials created “hybrid” organic-inorganic materials for transferring ultrasmall, high-aspect-ratio features into silicon for next-generation electronic devices.

To increase the processing speed and reduce the power consumption of electronic devices, the microelectronics industry continues to push for smaller and smaller feature sizes. Transistors in today’s cell phones are typically 10 nanometers (nm) across—equivalent to about 50 silicon atoms wide—or smaller. Scaling transistors down below these dimensions with higher accuracy requires advanced materials for lithography—the primary technique for printing electrical circuit elements on silicon wafers to manufacture electronic chips. One challenge is developing robust “resists,” or materials that are used as templates for transferring circuit patterns into device-useful substrates such as silicon.

Image: (Left to right) Ashwanth Subramanian, Ming Lu, Kim Kisslinger, Chang-Yong Nam, and Nikhil Tiwale in the Electron Microscopy Facility at Brookhaven Lab’s Center for Functional Nanomaterials. The scientists used scanning electron microscopes to image high-resolution, high-aspect-ratio silicon nanostructures they etched using a “hybrid” organic-inorganic resist.

How to catch a magnetic monopole in the act

2019/03/042019/03/08

Berkeley Lab-led study could lead to smaller memory devices, microelectronics, and spintronics

A research team led by the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has created a nanoscale “playground” on a chip that simulates the formation of exotic magnetic particles called monopoles. The study – published recently in Science Advances – could unlock the secrets to ever-smaller, more powerful memory devices, microelectronics, and next-generation hard drives that employ the power of magnetic spin to store data.

Follow the ‘ice rules’
For years, other researchers have been trying to create a real-world model of a magnetic monopole – a theoretical magnetic, subatomic particle that has a single north or south pole. These elusive particles can be simulated and observed by manufacturing artificial spin ice materials – large arrays of nanomagnets that have structures analogous to water ice – wherein the arrangement of atoms isn’t perfectly symmetrical, leading to residual north or south poles.

Image: Full image here. This nanoscale “playground” on a chip uses nanomagnets to simulate the formation of exotic magnetic particles called “monopoles.” Credit: Farhan/Berkeley Lab

Spin and charge frozen by strain

2018/05/092018/05/10

In the development of next-generation microelectronics, a great deal of attention has been given to the use of epitaxy (the deposition of a crystalline overlayer on a crystalline substrate) to tailor the properties of materials to suit particular applications. Correlated electron systems provide an excellent platform for the development of new microelectronic devices due to the presence of multiple competing ground states of similar energy. In some cases, strain can drive these systems between two or more such states, resulting in phase transitions and dramatic changes in the properties of the material. Often, the specific mechanism by which strain accomplishes such a feat is unknown. This was precisely the case in lanthanum cobaltite, LaCoO₃, which undergoes a strain-induced transition from paramagnet to ferromagnet, until a recent study carried out at the U.S. Department of Energy’s Advanced Photon Source (APS) revealed the intriguing microscopic phenomena at work in this system. These phenomena may play a role in spin-state and magnetic-phase transitions, regardless of stimulus, in many other correlated systems.

Lanthanum cobaltite is a perovskite, which means the structure can be thought of as made up of distorted cubes with cobalt at the cube centers, oxygen at the cube faces, and lanthanum at the cube corners. The cobalt ions have a nominal 3+ valence, meaning they lose three electrons to the neighboring oxygen ions. Bulk LaCoO₃ is paramagnetic (that is, having a net magnetization only in the presence of an externally applied magnetic field) above 110 Kelvin, and non-magnetic below that temperature. In its ground state, all the electrons on a given cobalt ion are paired, meaning their magnetic spins cancel each other out. These are so-called low-spin (LS) Co³⁺ ions, and when all of the cobalt ions are in this form, LaCoO₃ is non-magnetic.

Image: Upper left: Resonant x-ray scattering at the cobalt K-edge. Inversion of the spectra at the reflections shown indicates the presence of charge order. Upper right: X-ray diffraction reciprocal space maps at the (002) and (003) reflection indicating the high epitaxial quality of the films. The satellite peaks result from lattice modulations associated with the reduced symmetry in the film. Lower left: Schematic crystal structure of epitaxial LaCoO3 showing the arrangement of cobalt sites with different charge and spin. The circulated charge transfer from oxygen to the different cobalt sites is also shown. Lower right: Calculated total energy as a function of the difference between the in-plane Co-O bond lengths of HS and LS cobalt ions (∆rCo-O).