Yearly Archives: 2016

POET Technologies Inc. (OTCQX:POETF) (TSX Venture:PTK), a developer of opto-electronics fabrication processes for the semiconductor industry, today announced that it has taken one more significant step toward its goal of developing a fully integrated commercial opto-electronic technology platform.

The milestone achieved is the first demonstration of functional Hetero-junction Field Effect Transistors (HFETs) down to 250nm effective gate lengths on the same proprietary epitaxy and utilizing the same integrated process sequence that was previously used to demonstrate high performance detectors. This milestone is the latest in POET’s initiative to integrate a detector, HFET and laser together into a single chip, the three key components of an active optical cable, a current market target for POET.

“Two of the three critical individual pieces of an integrated opto-electronic product are now in place and undergoing their respective optimization cycles,” said Dr. Subhash Deshmukh, POET’s Chief Operating Officer.  “As reported earlier, we have encountered delays in completing the VCSEL milestone.  The VCSEL continues to be our focus, even while we simultaneously make progress on other aspects of the technology.  The characterization that has been done to date on the VCSEL points to required optimization of a few layers in a very complex and unique epitaxial stack and fine tuning of the resonant cavity mode. The new and optimized epitaxial structure is expected to be delivered to the foundry for processing over the next couple of months,” said Dr. Deshmukh.  “We have not uncovered any fundamental show-stoppers.  We are charting new territory here and as pointed out at the recent town hall meeting and at the annual meeting of shareholders, technical issues are commonly encountered throughout the R&D process and we are systematically understanding and addressing these issues.”

POET has already demonstrated electrical functionality of the VCSEL with desired thyristor characteristics and demonstrated lasing modes through optical pumping of the VCSEL cavity (in other words light emission was detected on the epitaxial wafer surface).  However in order to enable electrical pumping of the VCSEL, the team has had to redesign some aspects of the epitaxial stack. VCSEL functionality was previously verified in a lab setting and the functionality of that original laser has been retested and reconfirmed.

“POET management is delighted to report this new achievement and reaffirms their confidence in the roadmap and progress in the lab to fab to commercialization of monolithic opto-electronic products. We will provide the next update around the earnings call, which we intend to schedule for early Q4 2016,” said Dr. Suresh Venkatesan.

Europe’s largest electronics manufacturing exhibition SEMICON Europa (25-27 October) will take place in Grenoble at ALPEXPO. SEMICON Europa connects exhibitors and attendees to collaborate and network with over 5,800 engineers, executives, and key decision-makers. Over 70 percent of visitors make buying and investment decisions. SEMICON Europa brings Europe together for the latest advances in IC manufacturing, flexible hybrid electronics, MedTech, automotive electronics, imaging, design and fabless, Smart Manufacturing, materials, power electronics, and more.

Highlights of SEMICON Europa include:

  • Pavilions and Cluster Segments: Design and Fabless; Imaging; MEMS, Test & Packaging; Secondary Equipment; Innovation Village; and ALLE DES CLUSTERS
  • Materials Package: Includes Power Electronics Conference and 2016FLEX (flexible hybrid electronics), plus sessions on Electronics for Automotive, Advanced Materials, MedTech and Photonics
  • Smart and Sustainable Manufacturing Conference: Features Smart Manufacturing presentations from NXP Semiconductor, ST Microelectronics, Technische Universitat Dresden; plus Sustainable Manufacturing presentations from Intel, Infineon Technologies, DAS Environmental Expert GmbH, and University of Dublin

Featuring over 100 hours of technical sessions and presentations, SEMICON Europa also includes:

  • Market Briefing
  • Semiconductor Manufacturing & Technology: 20th Fab Management Forum plus sessions on Lithography, Photonics, and MEMS
  • Packaging Conference and Integrated Test sessions
  • 2016FLEX Europe: Silicon electronics and flexible systems, flexible electrical components, materials advancements, applications and new developments
  • Application and Innovation: Imaging Conference, Power Electronics Conference, and sessions on MedTech, Automotive Electronics, and “What’s Next?”

SEMICON Europa rotates between Grenoble (France) and Dresden (Germany), two of Europe’s largest epicenters. With the support of public and private stakeholders across Europe, the new SEMICON Europa enables exhibitors to reach new audiences and business partners and take full advantage of the strong microelectronic clusters in Europe. Over 350 exhibiting companies at SEMICON Europa represent the suppliers of Europe’s leading electronics companies. Learn more about exhibiting at SEMICON Europa.

SEMICON Europa 2016 sponsors include: e2v, EV Group, Lam Research, NovaCentrix, SiConnex, SPIL Siliconware, Tokyo Electron, and VAT.  To secure your exhibition space and/or to learn more about SEMICON Europa (exhibition or registration), please visit: www.semiconeuropa.org/en.

Lam Research Corp. (NASDAQ: LRCX), an advanced manufacturer of semiconductor equipment, today introduced an atomic layer deposition (ALD) process for depositing low-fluorine-content tungsten films, the latest addition to its ALTUS family of products. With the industry’s first low-fluorine tungsten (LFW) ALD process, the ALTUS Max E Series addresses memory chipmakers’ key challenges and enables the continued scaling of 3D NAND and DRAM devices. Building on Lam’s market-leading product portfolio for memory applications, the new system is gaining market traction worldwide, winning production positions at leading 3D NAND and DRAM manufacturers and placement at multiple R&D sites.

“Consumer demand for ever more powerful devices is driving the need for high-capacity, high-performance storage, and deposition and etch are key process technology enablers of advanced memory chips,” said Tim Archer, Lam’s chief operating officer. “With the addition of the ALTUS Max E Series, we are expanding our memory portfolio and enabling our customers to capitalize on this next wave of industry drivers. Over the past twelve months, as the 3D NAND inflection has accelerated, we have doubled our shipments for these applications, leading to the largest deposition and etch installed base in our 3D NAND served markets.”

As manufacturers increase the number of memory cell layers for 3D NAND, two issues have become apparent for tungsten deposition in the word line fill application. First, fluorine diffusion from the tungsten film into the dielectrics can cause physical defects. Second, higher cumulative stress in devices with more than 48 pairs has resulted in excessive bowing. The resulting defects and stress can cause yield loss, as well as degraded electrical performance and device reliability. Because of these issues, tungsten films for advanced 3D NAND devices must have significantly reduced fluorine and intrinsic stress. Further, as critical dimensions shrink, resistance scaling becomes more challenging for the DRAM buried word line, as well as for metal gate/metal contact applications in logic devices.

“As memory chip manufacturers move to smaller nodes, the features that need to be filled are increasingly narrow and have higher aspect ratios,” said Sesha Varadarajan, group vice president, Deposition Product Group. “Lam’s new LFW ALD solution uses a controlled surface reaction to tune stress and fluorine levels and to lower resistance, all while delivering the required tungsten fill performance and productivity. When compared to chemical vapor deposition tungsten, the ALTUS Max E Series lowers fluorine content by up to 100x, lowers stress by up to 10x, and reduces resistivity by over 30%, solving some of our customers’ most critical scaling and integration challenges.”

The ALTUS Max E Series with LFW ALD technology offers a unique all-ALD deposition process that leverages Lam’s PNL (Pulsed Nucleation Layer) technology, which is the industry benchmark for tungsten ALD with 15 years of market leadership and more than 1,000 modules in production. Lam led the transition of chemical vapor deposition (CVD) tungsten nucleation to ALD tungsten nucleation with its PNL technology. The company continued that leadership by advancing low-resistivity tungsten solutions with its products ALTUS Max with PNLxT™, ALTUS Max with LRWxT, and ALTUS Max ExtremeFill for enhanced fill performance.

The ALTUS products use Lam’s quad-station module (QSM) architecture to allow per-station optimization of tungsten nucleation and fill for fluorine, stress, and resistance without compromising fill performance since station temperature can be set independently. The QSM configuration also maximizes productivity of the all-ALD process by providing up to 12 pedestals per system, enabling the highest footprint productivity in the industry.

Toshiba America Electronic Components, Inc. (TAEC) will be on hand at the Flash Memory Summit (FMS) this week to showcase its latest memory and storage solutions. The inventor and one of the world’s largest producers of NAND flash, Toshiba will leverage FMS as a stage to highlight key technologies, including its BiCS FLASH 64-layer, 256Gb 3D flash memory – and to debut an all-flash solution for big data analytics. The company will also give one of the Summit’s keynote presentations. In keeping with this year’s FMS theme of high density NAND flash memory for vertical applications, Toshiba will focus on the needs of the enterprise, data center, automotive, industrial, mobile and client markets. Toshiba will be located in its theater-style booth (#407) on the show floor at the Santa Clara Convention Center from August 9-11.

Toshiba’s Shigeo (Jeff) Ohshima, technology executive, SSD, and Yoichiro Tanaka, senior fellow, will jointly present a keynote session titled: “New 3D Flash Technologies Offer Both Low Cost and Low Power Solutions.” Taking place on Tuesday, August 9 from noon – 12:30 p.m., the session will focus on the need for multiple 3D technologies to support today’s new flash applications. Emphasis will be placed on the data-intensive tasks such as real-time analytics, computational genomics, cloud computing, and video and image processing that are driving the need for high-density, low-cost solutions.

3D Flash Memory: Toshiba Continues to Lead the Way
Toshiba’s 3D flash memory solution, BiCS FLASH, will play a prominent role this year at FMS. Based on Toshiba’s cutting-edge stacking process, 3D BiCS FLASH makes larger capacities possible for enterprise applications, surpassing the capacity of mainstream two dimensional NAND flash memory while enhancing reliability and endurance and boosting performance.

With samples now shipping, Toshiba’s 64-layer 3D flash memory builds on the company’s reputation as leaders in this space – Toshiba was the first to introduce 48-layer 3D flash memory, which it debuted in March of last year. Underlining this commitment to next-generation memory solutions and furthering its momentum in the market, Toshiba recently celebrated the opening of its new Fab 2. This new semiconductor fabrication facility is dedicated to the production of its 3D flash memory solutions.

Additionally, Toshiba will showcase its new BG series solid state drive (SSD) family. Toshiba’s new single-package ball grid array (BGA) NVMe PCI Express (PCIe) Gen3 x2 SSD features BiCS FLASH deploying 3-bit-per-cell (TLC) technology, and utilizes an in-house Toshiba-developed controller and firmware for a fully vertically developed solution. This helps to ensure that the technology is tightly integrated for optimal performance, power consumption and reliability.

Flashmatrix Revealed and More
FMS will mark the debut of Toshiba’s new, all-flash, big data analytic platform technology: Flashmatrix. This platform represents a new breed of superconverged infrastructure that features integrated compute, storage and network elements optimized for high performance. This makes it suited for hybrid cloud architectures and edge-based applications that require highly distributed analytic capabilities. Flashmatrix will be demoed in the Toshiba booth.

The recently launched OCZ RD400 NVM Express® M.2 SSD Series will also be demoed at the Toshiba booth, running live in an ORIGIN PC MILLENNIUM desktop. The RD400 Series outperforms SATA SSDs by more than 4.5 times in sequential read (up to 2,600MB/s), and more than 3 times in sequential write performance (up to 1,600MB/s), increasing storage bandwidth for data-intensive workloads. ORIGIN PC is currently leveraging the performance of RD400 1024GB SSDs in several system configurations to provide ample storage capacity for custom gaming and professional PC builds.

Soft materials are great at damping energy — that’s why rubber tires are so good at absorbing the shock of bumps and potholes. But if researchers are going to build autonomous soft systems, like soft robots, they’ll need a way to transmit energy through soft materials.

Now, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), in collaboration with colleagues at the California Institute of Technology, have developed a way to send mechanical signals through soft materials.

The research is described in the Proceedings of the National Academy of Sciences.

“Soft autonomous systems have received a lot of attention because, just like the human body or other biological systems, they can be adaptive and perform delicate movements. However, the highly dissipative nature of soft materials limits or altogether prevents certain functions,” said Jordan Raney, postdoctoral fellow at SEAS and first author of the paper. “By storing energy in the architecture itself we can make up for the energy losses due to dissipation, allowing the propagation of mechanical signals across long distances.”

The system uses the centuries-old concept of bistable beams — structures stable in two distinct state — to store and release elastic energy along the path of a wave. The system consists of a chain of bistable elastomeric beams connected by elastomeric linear springs. When those beams are deformed, they snap and store energy in the form of elastic deformation. As the signal moves down the elastomer, it snaps the beams back into place, releasing the stored energy and sending the signal downstream like a line of dominos. The bistable system prevents the signal from dissipating downstream.

“This design solves two fundamental problems in transmitting information through materials,” said Katia Bertoldi, the John L. Loeb Associate Professor of the Natural Sciences at SEAS and senior author of the paper.  “It not only overcomes dissipation, but it also eliminates dispersive effects, so that the signal propagates without distortion.  As such, we maintain signal strength and clarity from start to end.”

The beam geometry requires precise fabrication techniques. If the angle or thickness of one beam is off by one degree or millimeter, the whole system fails.

The team used advanced 3D printing techniques to fabricate the system.

“We’re developing new materials and printing methods that enable the fabrication of soft materials with programmable bistable elements,” said Jennifer A. Lewis, the Hansjorg Wyss Professor of Biologically Inspired Engineering and coauthor of the paper.

The team designed and printed a soft logic gate using this system. The gate, which looks like a tuning fork, can be controlled to act as either as an AND or as an OR gate.

“It’s amazing what you can do using simple beams — a building block that’s been around hundreds of years,” said Bertoldi. “You can do new stuff with a very old, well studied and very simple component.”

This research was supported by the National Science Foundation and the Harvard University Materials Research Science and Engineering Center (MRSEC).

Towards a better screen


August 9, 2016

Harvard University researchers have designed more than 1,000 new blue-light emitting molecules for organic light-emitting diodes (OLEDs) that could dramatically improve displays for televisions, phones, tablets and more.

OLED screens use organic molecules that emit light when an electric current is applied. Unlike ubiquitous liquid crystal displays (LCDs), OLED screens don’t require a backlight, meaning the display can be as thin and flexible as a sheet of plastic. Individual pixels can be switched on or entirely off, dramatically improving the screen’s color contrast and energy consumption. OLEDs are already replacing LCDs in high-end consumer devices but a lack of stable and efficient blue materials has made them less competitive in large displays such as televisions.

The interdisciplinary team of Harvard researchers, in collaboration with MIT and Samsung, developed a large-scale, computer-driven screening process, called the Molecular Space Shuttle, that incorporates theoretical and experimental chemistry, machine learning and cheminformatics to quickly identify new OLED molecules that perform as well as, or better than, industry standards.

“People once believed that this family of organic light-emitting molecules was restricted to a small region of molecular space,” said Alán Aspuru-Guzik, Professor of Chemistry and Chemical Biology, who led the research. “But by developing a sophisticated molecular builder, using state-of-the art machine learning, and drawing on the expertise of experimentalists, we discovered a large set of high-performing blue OLED materials.”

The research is described in the current issue of Nature Materials.

The biggest challenge in manufacturing affordable OLEDs is emission of the color blue.

Like LCDs, OLEDs rely on green, red and blue subpixels to produce every color on screen.  But it has been difficult to find organic molecules that efficiently emit blue light. To improve efficiency, OLED producers have created organometallic molecules with expensive transition metals like iridium to enhance the molecule through phosphorescence. This solution is expensive and it has yet to achieve a stable blue color.

Aspuru-Guzik and his team sought to replace these organometallic systems with entirely organic molecules.

The team began by building libraries of more than 1.6 million candidate molecules. Then, to narrow the field, a team of researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), led by Ryan Adams, Assistant Professor of Computer Science, developed new machine learning algorithms to predict which molecules were likely to have good outcomes, and prioritize those to be virtually tested. This effectively reduced the computational cost of the search by at least a factor of ten.

“This was a natural collaboration between chemistry and machine learning,” said David Duvenaud, a postdoctoral fellow in the Adams lab and coauthor of the paper. “Since the early stages of our chemical design process starts with millions of possible candidates, there’s no way for a human to evaluate and prioritize all of them. So, we used neural networks to quickly prioritize the candidates based on all the molecules already evaluated.”

“Machine learning tools are really coming of age and starting to see applications in a lot of scientific domains,” said Adams.  “This collaboration was a wonderful opportunity to push the state of the art in computer science, while also developing completely new materials with many practical applications. It was incredibly rewarding to see these designs go from machine learning predictions to devices that you can hold in your hand.”

“We were able to model these molecules in a way that was really predictive,” said Rafael Gómez-Bombarelli, a postdoctoral fellow in the Aspuru-Guzik lab and first author of the paper.  “We could predict the color and the brightness of the molecules from a simple quantum chemical calculation and about 12 hours of computing per molecule. We were charting chemical space and finding the frontier of what a molecule can do by running virtual experiments.”

“Molecules are like athletes,” Aspuru-Guzik said. “It’s easy to find a runner, it’s easy to find a swimmer, it’s easy to find a cyclist but it’s hard to find all three. Our molecules have to be triathletes. They have to be blue, stable and bright.”

But finding these super molecules takes more than computing power — it takes human intuition, said Tim Hirzel, a senior software engineer in the Department of Chemistry and Chemical Biology and coauthor of the paper.

To help bridge the gap between theoretical modeling and experimental practice, Hirzel and the team built a web application for collaborators to explore the results of more than half a million quantum chemistry simulations.

Every month, Gómez-Bombarelli and coauthor Jorge Aguilera-Iparraguirre, also a postdoctoral fellow in the Aspuru-Guzik lab, selected the most promising molecules and used their software to create “baseball cards,” profiles containing important information about each molecule. This process identified 2500 molecules worth a closer look.  The team’s experimental collaborators at Samsung and MIT then voted on which molecules were most promising for application. The team nicknamed the voting tool “molecular Tinder” after the popular online dating app.

“We facilitated the social aspect of the science in a very deliberate way,” said Hirzel.

“The computer models do a lot but the spark of genius is still coming from people,” said Gómez-Bombarelli.

“The success of this effort stems from its multidisciplinary nature,” said Aspuru-Guzik. “Our collaborators at MIT and Samsung provided critical feedback regarding the requirements for the molecular structures.”

“The high throughput screening technique pioneered by the Harvard team significantly reduced the need for synthesis, experimental characterization, and optimization,” said Marc Baldo, Professor of Electrical Engineering and Computer Science at MIT and coauthor of the paper. “It shows the industry how to advance OLED technology faster and more efficiently.”

After this accelerated design cycle, the team was left with hundreds of molecules that perform as well as, if not better than, state-of-the-art metal-free OLEDs.

Applications of this type of molecular screening also extend far beyond OLEDs.

“This research is an intermediate stop in a trajectory towards more and more advanced organic molecules that could be used in flow batteries, solar cells, organic lasers, and more,” said Aspuru-Guzik. “The future of accelerated molecular design is really, really exciting.”

In addition to the authors mentioned, the manuscript was coauthored by Dougal Maclaurin, Martin A. Blood-Forsythe, Hyun Sik Chae, Markus Einzinger, Dong-Gwang Ha, Tony Wu, Georgios Markopoulos, Soonok Jeon, Hosuk Kang, Hiroshi Miyazaki, Masaki Numata, Sunghan Kim, Wenliang Huang and Seong Ik Hong.

The research was supported by the Samsung Advanced Institute of Technology.

Scientists at the Energy Department’s National Renewable Energy Laboratory (NREL), in collaboration with researchers at Shanghai Jiao Tong University (SJTU), devised a method to improve perovskite solar cells, making them more efficient and reliable with higher reproducibility.

The research, funded by the U.S. Department of Energy SunShot Initiative, involved hybrid halide perovskite solar cells and revealed treating them with a specific solution of methyl ammonium bromide (MABr) would repair defects, improving efficiency. The scientists converted a low-quality perovskite film with pinholes and small grains into a high-quality film without pinholes and with large grains. Doing so boosted the efficiency of the perovskite film in converting sunlight to 19 percent.

The efficiency of perovskites in converting sunlight into electricity has jumped from slightly less than 4 percent in 2009, when the first tests were done, to more than 22 percent today. However, the efficiency can fluctuate according to the skills of the researchers making perovskites at different laboratories, to somewhere between 15 percent and 20 percent.

Perovskite films are typically grown using a solution of precursor chemicals that form the crystals, which are then exposed to a second anti-solvent that removes the precursor solvent. The fast-crystallization process is almost an art. NREL researchers found that, because of the narrow time window for properly adding the anti-solvent, it is easy to miss that window and perovskite crystals with defects could form. Defects, like noncontinuous crystals and nonuniform crystals with relatively small crystallite sizes and pinholes, can significantly reduce the effectiveness of a perovskite cell.

The scientists from NREL and SJTU came up with a better method, using what’s called the Ostwald ripening process. The process involves small crystals dissolving and then redepositing onto larger crystals. The researchers were able to induce the Ostwald ripening process by treating the perovskite with a MABr solution. The amount of the solution proved key, as the ideal was proven to be about 2 milligrams per milliliter.

“With the Ostwald ripening process, different-sized nanocrystals formed with different film qualities could then grow into pinhole-free perovskite films with similar large crystal sizes,” the researchers noted in the article. “Thus, this new chemical approach enhances processing tolerance to the initial perovskite film quality and improves the reproducibility of device fabrication.”

The improved film quality made the cells more stable. The perovskite cells treated with MABr were shown to be more efficient than those without the treatment. Untreated cells had an efficiency of about 14 percent to 17 percent, while cells treated with the MABr solution had an efficiency of more than 19 percent.

Nanophoton introduces RAMANdrive – a new Wafer Analyzer – for a wide range of applications at semiconductor market at ICCGE-18 (the 18th International Conference on Crystal Growth and Epitaxy) in Nagoya, Japan, August 7th – 12th, 2016.

With sub-micron resolution, RAMANdrive provides stress-, polytype-, defect distribution etc. in 3 dimen- sions using the most powerful Raman Imaging Technology of Nanophoton. The dedicated 300 mm stage was developed for accurate and safe analysis of the whole wafer, while the Raman Imaging Sys- tem provides you with high performance data. Especially the unique Nanophoton Stage Navigation System features easy and fast operation by implementing your data from the regular inspection system and use it to move the wafer to all positions you are interested in for a detailed analysis.

Michael Verst – President/CEO of Nanophoton – commented: “Raman Imaging is one of the most exit- ing technologies for wafer analysis. It provides comprehensive data about stress, polytype, impurity or contamination non-destructively in all 3 dimensions. In combination with our dedicated 300 mm wafer stage, I strongly believe that our RAMANdrive will be a powerful tool especially for QA/QC as well as development work. It will substantially improve the yield ratio, but also accelerate the development of new materials etc. Nanophoton invested a substantial amount of efforts in the development and dur- ing all the time we worked closely with related experts to meet the requirements of our customers in the semiconductor industry.”

Screen Shot 2016-08-08 at 2.56.06 PM

Recognizing the massive growth potential of micro-electro-mechanical systems (MEMS) and sensors in Internet of Things (IoT) applications, MEMS & Sensors Industry Group (MSIG) will hold its third annual MEMS & Sensors Industry Group Conference Asia in Shanghai, China on September 13-14, 2016. Held in partnership with Shanghai Industrial Technology Research Institute (SITRI) and co-located with SENSOR CHINA, “The Internet of MEMS and Sensors Today and the Internet of TSensors Tomorrow” is a two-day conference focused on near- and long-term opportunities for MEMS and sensors in the IoT. MSIG and its members will also participate in a two-day exposition at SENSOR CHINA.

The IoT market is expanding rapidly, presenting huge market opportunities for MEMS and sensors. According to IHS Technology, the IoT market will grow from 15.4 billion devices in 2015 to 75.4 billion in 2025.

That growth has caught the attention of the global MEMS and sensors supply chain: “MEMS and sensors are critical to IoT devices,” said Karen Lightman, executive director, MEMS & Sensors Industry Group. “From smartphones that monitor air quality and agricultural sensors that manage irrigation to smart city applications that monitor structural health, adapt street lights to weather and light conditions, and enable smart roads, MEMS and sensors allow IoT devices to measure, monitor, sense and interact with our always-changing environment.”

Ms. Lightman added, “On September 13, attendees will gain actionable intelligence on the IoT devices of the near future — those applications that will reach commercialization within the next two to five years. On September 14, they will learn about the IoT devices that will come to market in ten to 20 years. Those speakers will address our TSensors vision — a transformational movement advocating the use of a trillion sensors to address major world problems — as they consider longer-term opportunities in the IoT.”

Conference Agenda
Featured presentations currently include:

Additional featured speakers include:

  • Masayuki Abe, manager, Corporate Production Technology, Asahi Kasei Corporation
  • Dr. Janusz Bryzek, CEO, eXo Systems, Inc., and founder, TSensors
  • Ahmed Busnaina, professor & director, NSF Center, Northeastern University
  • Susumu Kaminaga, executive senior advisor, SPP Technologies Co., Ltd.
  • Karen Lightman, executive director, MEMS & Sensors Industry Group
  • Ryoma Miyake, Process Development Group, Silicon Sensing Products, Ltd.
  • Keynote Speaker Tomy Runne, senior manager of planning and promotion department, Sensor Product Division, Murata Manufacturing Co., Ltd.
  • Keynote Speaker Dr. Jian Xu, executive general manager, Shanghai International Autocity Development Co., Ltd.

Panel
Context Computing — panel moderated by Leopold Beer, regional president AP, Bosch Sensortec, with panelists:

  • Xianfeng (Sean) Ding, director of sensing, Huawei Technologies
  • Ruizhen Liu, Shanghai Academy of Artificial Intelligence
  • Yang (Richard) Shi, industry strategy expert, Huawei Technologies

To continue advancing, next-generation electronic devices must fully exploit the nanoscale, where materials span just billionths of a meter. But balancing complexity, precision, and manufacturing scalability on such fantastically small scales is inevitably difficult. Fortunately, some nanomaterials can be coaxed into snapping themselves into desired formations-a process called self-assembly.

Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have just developed a way to direct the self-assembly of multiple molecular patterns within a single material, producing new nanoscale architectures. The results were published in the journal Nature Communications.

“This is a significant conceptual leap in self-assembly,” said Brookhaven Lab physicist Aaron Stein, lead author on the study. “In the past, we were limited to a single emergent pattern, but this technique breaks that barrier with relative ease. This is significant for basic research, certainly, but it could also change the way we design and manufacture electronics.”

Microchips, for example, use meticulously patterned templates to produce the nanoscale structures that process and store information. Through self-assembly, however, these structures can spontaneously form without that exhaustive preliminary patterning. And now, self-assembly can generate multiple distinct patterns-greatly increasing the complexity of nanostructures that can be formed in a single step.

“This technique fits quite easily into existing microchip fabrication workflows,” said study coauthor Kevin Yager, also a Brookhaven physicist. “It’s exciting to make a fundamental discovery that could one day find its way into our computers.”

The experimental work was conducted entirely at Brookhaven Lab’s Center for Functional Nanomaterials (CFN), a DOE Office of Science User Facility, leveraging in-house expertise and instrumentation.

Cooking up organized complexity

The collaboration used block copolymers-chains of two distinct molecules linked together-because of their intrinsic ability to self-assemble.

“As powerful as self-assembly is, we suspected that guiding the process would enhance it to create truly ‘responsive’ self-assembly,” said study coauthor Greg Doerk of Brookhaven. “That’s exactly where we pushed it.”

To guide self-assembly, scientists create precise but simple substrate templates. Using a method called electron beam lithography-Stein’s specialty-they etch patterns thousands of times thinner than a human hair on the template surface. They then add a solution containing a set of block copolymers onto the template, spin the substrate to create a thin coating, and “bake” it all in an oven to kick the molecules into formation. Thermal energy drives interaction between the block copolymers and the template, setting the final configuration-in this instance, parallel lines or dots in a grid.

“In conventional self-assembly, the final nanostructures follow the template’s guiding lines, but are of a single pattern type,” Stein said. “But that all just changed.”

Lines and dots, living together

The collaboration had previously discovered that mixing together different block copolymers allowed multiple, co-existing line and dot nanostructures to form.

“We had discovered an exciting phenomenon, but couldn’t select which morphology would emerge,” Yager said. But then the team found that tweaking the substrate changed the structures that emerged. By simply adjusting the spacing and thickness of the lithographic line patterns-easy to fabricate using modern tools-the self-assembling blocks can be locally converted into ultra-thin lines, or high-density arrays of nano-dots.

“We realized that combining our self-assembling materials with nanofabricated guides gave us that elusive control. And, of course, these new geometries are achieved on an incredibly small scale,” said Yager.

“In essence,” said Stein, “we’ve created ‘smart’ templates for nanomaterial self-assembly. How far we can push the technique remains to be seen, but it opens some very promising pathways.”

Gwen Wright, another CFN coauthor, added, “Many nano-fabrication labs should be able to do this tomorrow with their in-house tools-the trick was discovering it was even possible.”

The scientists plan to increase the sophistication of the process, using more complex materials in order to move toward more device-like architectures.

“The ongoing and open collaboration within the CFN made this possible,” said Charles Black, director of the CFN. “We had experts in self-assembly, electron beam lithography, and even electron microscopy to characterize the materials, all under one roof, all pushing the limits of nanoscience.”