Category Archives: LEDs

Using cutting-edge first-principles calculations, researchers at the University of California, Santa Barbara (UCSB) have demonstrated the mechanism by which transition metal impurities – iron in particular – can act as nonradiative recombination centers in nitride semiconductors. The work highlights that such impurities can have a detrimental impact on the efficiency of light-emitting diodes (LEDs) based on gallium nitride or indium gallium nitride.

This is a schematic illustration of Shockley-Read-Hall (SRH) recombination due to iron in GaN. Iron is a deep acceptor with a defect level (black line) close to the GaN conduction band (green). The charge density corresponding to this localized level is illustrated in the middle of the figure. Conventional SRH recombination (left) would proceed via electron capture from the conduction band into the defect level, but the overall rate would be limited by slow capture of holes because the defect level is far from the valence band (blue). The presence of excited states enhances the hole capture rate (right) such that the overall SRH recombination process becomes very efficient. Credit: Sonia Fernandez

This is a schematic illustration of Shockley-Read-Hall (SRH) recombination due to iron in GaN. Iron is a deep acceptor with a defect level (black line) close to the GaN conduction band (green). The charge density corresponding to this localized level is illustrated in the middle of the figure. Conventional SRH recombination (left) would proceed via electron capture from the conduction band into the defect level, but the overall rate would be limited by slow capture of holes because the defect level is far from the valence band (blue). The presence of excited states enhances the hole capture rate (right) such that the overall SRH recombination process becomes very efficient. Credit: Sonia Fernandez

For LEDs, high-purity material is essential to lighting technology, such as residential and commercial solid-state lighting, adaptive lighting for automobiles, and displays for mobile devices. Imperfections at the atomic scale can limit the performance of LEDs through a process known as Shockley-Read-Hall recombination. The operation of an LED relies on the radiative recombination of electrons and holes, which results in the emission of photons. Defects or impurities can act as a source of nonradiative recombination and prevent the emission of light, lowering the LED efficiency.

The UCSB researchers, in collaboration with researchers from Rutgers University, the University of Vienna, the KTH Royal Institute of Technology in Sweden and the Center for Physical Sciences and Technology in Lithuania, have identified that iron, even at concentrations less than parts-per-million, can be highly detrimental.

Transition metal impurities such as iron have long been known to severely impact devices based on traditional semiconductors such as silicon and gallium arsenide, leading these impurities to be referred to as “killer centers.” It is therefore surprising that little attention has been devoted to understanding the role of transition metals in recombination dynamics in GaN.

“A naïve application of Shockley-Read-Hall theory, based on an inspection of defect levels within the band gap, would lead one to conclude that iron in GaN would be harmless,” explained Dr. Darshana Wickramaratne, lead author on the paper. “However, our work shows that excited states of the impurity play a key role in turning it into a killer center.”

The UCSB scientists identified a recombination pathway by which iron can lead to severe efficiency loss. Sophisticated first-principles calculations were essential to identify and understand the role of the excited states in the recombination process.

“Taking these excited states into account completely changes the picture,” emphasized Dr. Audrius Alkauskas, another member of the research team. “We strongly suspect that such excited states play a key role in other recombination phenomena, opening up new avenues for research.”

The results highlight that strict control over growth and processing is required to prevent the unintentional introduction of transition metal impurities. Sources of iron contamination include the stainless steel reactors that are used in some growth techniques for nitride semiconductors.

“Increasing the efficiency of light emission is a key goal for the solid-state lighting industry,” said UCSB Materials Professor Chris Van de Walle, who led the research team. “Our work focuses attention on the detrimental impact of transition metals and the importance of suppressing their incorporation.”

Gallium nitride (GaN) has emerged as one of the most important and widely used semiconducting materials. Its optoelectronic and mechanical properties make it ideal for a variety of applications, including light-emitting diodes (LEDs), high-temperature transistors, sensors and biocompatible electronic implants in humans.

In 2014, three Japanese scientists won the Nobel Prize in physics for discovering GaN’s critical role in generating blue LED light, which is required, in combination with red and green light, to produce white LED light sources.

Now, four Lehigh engineers have reported a previously unknown property for GaN: Its wear resistance approaches that of diamonds and promises to open up applications in touch screens, space vehicles and radio-frequency microelectromechanical systems (RF MEMS), all of which require high-speed, high-vibration technology.

The researchers reported their findings in August in Applied Physics Letters (APL) in an article titled “Ultralow wear of gallium nitride.” The article’s authors are Guosong Zeng, a Ph.D. candidate in mechanical engineering; Nelson Tansu, Daniel E. ’39 and Patricia M. Smith Endowed Chair Professor in the Electrical and Computer Engineering department, and Director of the Center for Photonics and Nanoelectronics (CPN); Brandon A. Krick, assistant professor of mechanical engineering and mechanics; and Chee-Keong Tan ’16 Ph.D., now assistant professor of electrical and computer engineering at Clarkson University.

GaN’s electronic and optical properties have been studied extensively for several decades, said Zeng, the lead author of the APL article, but virtually no studies have been done of its tribological properties, that is, its resistance to the mechanical wear imposed by reciprocated sliding.

“Our group is the first to investigate the wear performance of GaN,” said Zeng. “We have found that its wear rate approaches that of diamonds, the hardest material known.”

Wear rate is expressed in negative cubic millimeters of Newton meters (Nm). The rate for chalk, which has virtually no wear resistance, is on the order of 10 2 mm3/Nm, while that of diamonds is between 10-9 and 10-10, making diamonds eight orders of magnitude more wear resistant than chalk. The rate for GaN ranges from 10¬-7 to 10-9, approaching the wear resistance of diamonds and three to five orders of magnitude more wear resistant than silicon (10-4).

The Lehigh researchers measured the wear rate and friction coefficients of GaN using a custom microtribometer to perform dry sliding wear experiments. They were surprised by the results.

“When performing wear measurements of unknown materials,” they wrote in APL, “we typically slide for 1,000 cycles, then measure the wear scars; [these] experiments had to be increased to 30,000 reciprocating cycles to be measurable with our optical profilometer.

“The large range in wear rates (about two orders of magnitude)…can provide insight into the wear mechanisms of GaN.”

That range in wear resistance, the researchers said, is caused by several factors, including environment, crystallographic direction and, especially, humidity.

“The first time we observed the ultralow wear rate of GaN was in winter,” said Zeng. “These results could not be replicated in summer, when the material’s wear rate increased by two orders of magnitude.”

To determine how the higher summer humidity was affecting GaN’s wear performance, the researchers put their tribometer in a glove box that can be backfilled with either nitrogen or humid air.

“We observed that as we increased the humidity inside the glove box, we also increased the wear rate of GaN,” said Zeng.

Zeng gave a presentation about the Lehigh project in October at the International Workshop on Nitride Semiconductors (IWN 2016) in Orlando, Florida. The session at which he spoke was titled “Wear of Nitride Materials and Properties of GaN-based structures.” Zeng was one of seven presenters at the session and the only one to discuss the wear properties of GaN and other III-Nitride materials.

Tansu, who has studied GaN for more than a decade, and Krick, a tribology expert, became curious about GaN’s wear performance several years ago when they discussed their research projects after a Lehigh faculty meeting.

“Nelson asked me if anyone had ever investigated the friction and wear properties of gallium nitride,” said Krick, “and I said I didn’t know. We checked later and found a wide-open field.”

Tansu said the group’s discovery of GaN’s hardness and wear performance could have a dramatic effect on the electronic and digital device industries. In a device such as a smartphone, he said, the electronic components are housed underneath a protective coating of glass or sapphire. This poses potential compatibility problems which could be avoided by using GaN.

“The wear resistance of GaN,” said Tansu, “gives us the opportunity to replace the multiple layers in a typical semiconductor device with one layer made of a material that has excellent optical and electrical properties and is wear-resistant as well.

“Using GaN, you can build an entire device in a platform without multiple layers of technologies. You can integrate electronics, light sensors and light emitters and still have a mechanically robust device. This will open up a new paradigm for designing devices. And because GaN can be made very thin and still strong, it will accelerate the move to flexible electronics.”

In addition to its unexpectedly good wear performance, said Zeng, GaN also has a favorable radiation hardness, which is an important property for the solar cells that power space vehicles. In outer space, these solar cells encounter large quantities of very fine cosmic dust, along with x-rays and gamma rays, and thus require a wear-resistant coating, which in turn needs to be compatible with the cell’s electronic circuitry. GaN provides the necessary hardness without introducing compatibility issues with the circuitry.

The Lehigh group has begun collaborating with Bruce E. Koel, a surface chemistry expert and professor of chemical and biological engineering at Princeton University, to gain a better understanding of the interaction of GaN and water under contact. Koel was formerly a chemistry professor and vice president for research and graduate studies at Lehigh.

To determine the evolution of wear with GaN, the group has subjected GaN to stresses by running slide tests in which the slide distance and the corresponding number of cycles are varied. The group then uses an x-ray photoelectron spectrometer (XPS), which can identify the elemental composition of the first 12 nanometers of a surface, to scan the unworn surface of the GaN, the scar created by the slide machine, and the wear particles deposited by the slide machine on either side of the scar.

The group plans next to use aberration-corrected transmission electron microscopy to examine the lattice of atoms beneath the scar. Meanwhile, they will simulate a test in which the lattice is strained with water in order to observe the variations caused by deforming energy.

“This is a very new experiment,” said Zeng. “It will enable us to see dynamic surface chemistry by watching the chemical reaction that results when you apply shear, tensile or compressive pressure to the surface of GaN.”

BY PETE SINGER, Editor-in-Chief

I’m delighted to announce that The ConFab, our premier semiconductor manufacturing conference and networking event, will be held at the iconic Hotel del Coronado in San Diego on May 14-17, 2017. For more than 12 years, The ConFab, an invitation-only executive conference, has been the destination for key industry influencers and decision-makers to connect and collab- orate on critical issues.

The ConFab is the best place to seek a deeper under- standing on these and other important issues, offering a unique blend of market insights, technology forecasts and strategic assessments of the challenges and opportu- nities facing semiconductor manufacturers. In changing times, it’s critical for people to get together in a relaxed setting, learn what’s new, connect with old friends, make new acquaintances and find new business opportunities, and that’s what The ConFab is all about.

I’m also pleased to announce the addition of David J. Mount to The ConFab team as marketing and business development manager. Mount has a rich history in the semiconductor manufacturing equipment business and will be instrumental in guiding continued growth, and expanding into new high growth areas.

Mainstream semiconductor technology will remain the central focus of The ConFab, and the conference will be expanded with additional speakers, panelists, and VIP attendees who will participate from other fast growing and emerging areas. These include biomedical, automotive, IoT, MEMS, LEDs, displays, thin film batteries, photonics and advanced packaging. From both the device maker and the equipment supplier perspective, The ConFab 2017 is a must-attend networking conference for business leaders.

The ConFab conference program is guided by a stellar Advisory Board, with high level representatives from GlobalFoundries, Texas Instruments, TSMC, Cisco, Samsung, Intel, Lam Research, KLA-Tencor, ASE, NVIDIA, the Fab Owners Association and elsewhere.

Details on the invitation-only conference are at: www. theconfab.com. For sponsorship inquiries, contact Kerry Hoffman at [email protected]. For those interested in attending as a guest or qualifying as a VIP, contact Sally Bixby at [email protected].

What is your China strategy?


October 30, 2016

This article was originally posted on SemiMD.com and was featured in the October 2016 issue of Solid State Technology.

By Dave Lammers, Contributing Editor

Equipment vendors have a lot on their plates now, with memory customers pushing 3D NAND, foundries advancing to the 7 nm node, and 200mm fabs clamoring to come up with hard-to-find tools.

China, which has renewed its investments in displays, packaging, and both 200mm and 300mm front-end fab capacity, is another challenge.

“All the managers in my company are scrambling to adjust their budgets so they can support China. I can tell you people are booking lots of flights to Shanghai,” said one engineer at a major equipment supplier.

Bill McClean, president of IC Insights (Scottsdale, AZ), said China is fast becoming a center for 3D NAND production, as several companies expand production in China. Intel is converting its Dalian, China fab partly to 3D NAND, and Toshiba might very well make a deal in China to build a 3D NAND fab there, he said.

“China could be the 3D NAND capital of the world,” McClean said at The ConFab conference in Las Vegas. While the U.S. government limits exports of leading-edge technologies on national security concerns, 3D NAND relies more on overlay and etch techniques at relaxed (40nm) design rules, he noted.

“Since the 3D NAND makers are not pushing feature sizes, it doesn’t raise red flags like if Chinese companies wanted FinFET technology. That is when the alarms go off,” McClean said.

However, McClean said the 3D NAND market is not immune to the oversupply issues that now face the DRAM makers. “I’ve seen this rodeo before,” McClean said.

China’s domestic IC market is slightly more than $100 billion, McClean said, while chip production in China was about $13 billion last year, representing just under 5 percent of worldwide production (Figure 1).

The difference between consumption and domestic production, referred to as the delta, is made up by imports. “This 13 percent (from domestic suppliers) drives the Chinese government crazy. Yes, they will close that gap a little bit, but not to the extent that they think,” McClean told The ConFab audience in mid-June.

Robert Maire, who consulted for SMIC on its initial public offering in the United States, spoke at length about China at the SEMI Advanced Semiconductor Manufacturing Conference (ASMC) in Saratoga Springs, N.Y. Amid the mergers and acquisition frenzy of last year, China managed to pull off the acquisitions of CMOS image sensor vendor Omnivision, memory maker ISSI, the RF business of NXP, Pericom Semiconductor, and Mattson Technology. (McClean said he believes that if the Omnivision acquisition were attempted in today’s more China-wary environment that Washington would block the deal).

Maire, principal at Semiconductor Advisors (New York), said China is far behind in its domestic semiconductor production equipment business. “If China has 14nm production capacity, but buys all of its equipment from abroad, it doesn’t really help them that much. China is getting started in equipment, but it has a lot of catching up to do.”

Scott Foster, a partner in market intelligence firm TAP Japan (Tokyo), said China must have an international scope in the equipment sector if it hopes to compete with the likes of Applied, Lam, and other well-established vendors. A few of Japan’s equipment suppliers are succeeding while operating in relatively narrow niches, but overall, competing globally is a challenge for mid-sized Japanese equipment companies. “If this is what is happening to Japanese equipment vendors, what chance do Chinese companies have?” Foster said.

Packaging may prove to be key

Skeptics of China’s prospects might take a long look at China’s success in packaging, an area where China is succeeding, in part by acquisitions of Asia-based companies, notably STATS ChipPAC (Singapore), which was acquired by Jiangsu Changjiang Electronics Technology Co. (JCET) last year. Separately, SMIC and JCET formed a joint venture to focus on chip scale packaging, wafer bumping, and fan-out wafer level packaging. The packaging joint venture is located 90 minutes from Shanghai, said Sonny Hui, senior vice president of worldwide marketing at SMIC.

Jim Walker, the packaging analyst at market research firm Gartner, said China-based packaging is now valued at nearly half (43 percent) of all worldwide packaging value by IDMs and OSATs. While the packaging industry overall is dealing with price pressures, the advent of wafer level packaging, and other forms of multi-chip integration, bodes well for the higher end of the back-end industry.

“As the semiconductor industry matures and Moore’s Law scaling slows, multi-chip integration via packaging is providing system vendors with a faster time-to-market, and a lower-cost means, of solving system-level challenges,” Walker said.

Packaging multiple chips in a module is likely to play a key role in the Internet of Things (IoT) markets, Walker said. Automotive, medical, home, and consumer solutions are all “heavily reliant on packaging,” he said.

Sam Wang, a Gartner analyst who focuses on foundries, pointed out at Semicon West that China’s semiconductor industry faces continued challenges in a hotly contested foundry market. Few China-based foundries have enjoyed the strong growth that SMIC has demonstrated, he said. (SMIC has been “running at very high utilizations, and we are working very hard to solve the problem,” said SMIC’s Hui.)

While SMIC has enjoyed double-digit growth for several years, the five second-tier Chinese foundries – — Shanghai Huahong Grace, CSMC, HuaLi, XMC, and ASMC — saw declining revenues year-over-year in 2015. Overall, China-based foundries accounted for just 7.8 percent of total worldwide foundry capacity last year, and the overall growth rate by Chinese foundries “is way below the expectations of the Chinese government,” Wang said.

China-based companies are focusing partly on MEMS and other devices made on 200mm wafers, including analog, sensors, and power. SMIC’s Hui said “most of our customers don’t see much benefit to migrate to 12-inch. 200mm still has a lot of potential; just consider the hundreds of products still made on 180nm technology, which was developed 20 years ago. Many customers still see that as a sweet spot.”

Foster, who has three decades of tech-watching experience from his base in Tokyo, said the 200mm wafer fabs being built in China will make products that “do not need the gigantic scale” required of Intel, TSMC, Samsung and Toshiba. Figure 2, courtesy of SEMI, shows the seventeen 200mm wafer fabs/lines that are expected begin operation in 2015 to 2019. Six of the seventeen will be in China.

“After decades of trying, China has found a market-based strategy: building scale and experience from the bottom up. In the long run, this is likely to be far more effective than going out to buy foreign companies,” Foster said.

Display is another area China is counting on. In an Aug. 18 conference call following a strong quarter, Applied Materials chief financial officer Bob Halliday told analysts: “In display, we recorded record orders of $803 million with more than half coming from projects in China.”

The Applied CFO also said, “Just listening to the Chinese government, they’re in this for a long-term and their interest in investing in the semiconductor industry is probably only going to increase.”

Kateeva turns to China funds

China is often lumped together with other Asian nations as a country that has a government-led, me-too, follower mentality. But increasingly, China is either proving innovative itself, or able to quickly adopt innovations from the West.

At the Innovation Forum at Semicon West, Conor Madigan, co-founder of ink jet printer startup Kateeva (Newark, Calif.) spoke about the readiness of Chinese venture capital funds to step in where Silicon Valley-based VCs were overly hesitant. China proved a more receptive place to raise money than the United States, though the early establishment of the M.I.T. spinout did come from U.S. based sources.

After its initial development effort, Kateeva figured it needed more than $100 million to accomplish its goals. After making the rounds to raise funds in the United States without success, Kateeva turned to China, where five different funds eventually became investors.

Asked why Chinese investors were willing to back Kateeva when funds in the United States and other Asian countries were reluctant, Madigan pointed to a confluence of factors.

The Chinese government had identified OLED displays as a focus of its Five Year Plan. The follow-on economic plan further identified inkjet technology as a critical technology. Investors in China favor companies which can provide the equipment for products, such as OLEDs, which have the government’s blessing and financial support. That government support reduced the investment risks in ways that are not readily seen in Japan or the United States, he said.

Madigan had studied OLEDs as an undergraduate at Princeton University, and then studied under an M.I.T. professor who had developed ink jet technology for large formats.

Though an early goal was to use large-format inkjet to deposit the RGB materials in OLEDs, the Kateeva team learned that its YieldJet system could be adapted to solve a more urgent problem: thin film encapsulation (TFE). It “pivoted” on the advice of an early customer, which fortunately already had developed the “ink” which under UV light would form a uniform encapsulation layer for the large OLED substrates required for TVs and other large display applications.

Two display companies in China identified Kateeva as a strategic partner, which allowed Kateeva to raise money from private Chinese VC funds, rather than taking money from regional government funds which might have asked Kateeva to locate its manufacturing operations in their local area.

Madigan also pointed to the tendency of U.S.-based venture capital funds to favor software companies over manufacturing-focused opportunities. As VCs make money in software-related startups, the funds gradually have more partners and investors which favor software because that is what they are familiar with.

VC fund managers with backgrounds in software “want to invest in the space that they understand. In the United States, that often means software, because you pick companies in the space that you understand.”

Kateeva, the OLED production equipment developer, today announced the appointment of Mark R. Shaw, Ph.D. as Senior Vice President of Human Resources (HR). Previously, Shaw worked at Lam Research and Applied Materials. He joins Kateeva at a time of rapid growth. He’ll build a comprehensive HR infrastructure to support the company’s accelerating global business, with strategic initiatives to attract, inspire and reward top talent, world-wide.

Shaw has spent 25+ years driving transformational HR programs at multi-billion-dollar capital equipment companies with global operations, multiple product lines, and thousands of employees. Over time, he has led multi-national teams in shaping and executing HR solutions to support myriad corporate transactions and significant change events. This included: establishing HR organizations for multiple joint ventures in the US, Asia and Europe; developing comprehensive executive leadership and workforce strategies for new regional markets; unifying compensation programs across multiple geographies, and driving successful M&A integrations with practical change-management protocols.

“Few candidates know the business of leveraging people-power to support a fast-growing, global hardware company as thoroughly as Mark,” said Kateeva President and COO, Conor Madigan. “At Lam Research and Applied Materials, he navigated major events and complex global interactions, offering innovative and thoughtful HR solutions to maximize success outcomes for his employer and fellow employees. With our market trajectory already presenting similar growth events for Kateeva, we’re thrilled that Mark will lead the effort to build a talent-optimization infrastructure to help us expertly harness the opportunities.”

For Shaw, the new role is a unique opportunity to apply HR best-practices that made his previous employers rewarding workplaces. “In its short life, Kateeva has already achieved the near-impossible by commercializing a disruptive OLED-enabling technology that catapulted to market leadership in under two years. The same DNA behind that success will soon propel the company into new markets. For me, that means designing and implementing agile strategies that embolden the culture without sacrificing the entrepreneurial vibe that fueled the successes. I’m excited to accept the challenge.”

Shaw joined Kateeva from Lam Research where he was Vice President of HR for sales, service and manufacturing. He led organization and talent initiatives that included succession, employee development, sales capability, and field technical resources. Following Lam’s acquisition of Novellus Systems, he helped establish new organization structures and select new leaders. He also designed and implemented employee retention programs.

Previously, Shaw spent nearly 15 years at Applied Materials. He ended his tenure there as HR VP for the international sales and marketing organization, supporting 4000 regional employees in 15 countries.

Shaw holds a B.A. degree in speech from California State University at Hayward. He earned an M.A. degree in speech communication from San Francisco State University, and a Ph.D. degree in speech communication from Pennsylvania State University.

Detailing the molecular makeup of materials — from solar cells to organic light-emitting diodes (LEDs) and transistors, and medically important proteins — is not always a crystal-clear process.

To understand how materials work at these microscopic scales, and to better design materials to improve their function, it is necessary to not only know all about their composition but also their molecular arrangement and microscopic imperfections.

Now, a team of researchers working at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has demonstrated infrared imaging of an organic semiconductor known for its electronics capabilities, revealing key nanoscale details about the nature of its crystal shapes and orientations, and defects that also affect its performance.

This image shows the crystal shape and height of a material known as PTCDA, with height represented by the shading (white is taller, darker orange is lowest). The white scale bar represents 500 nanometers. The illustration at bottom is a representation of the crystal shape. Credit: Berkeley Lab, CU-Boulder

This image shows the crystal shape and height of a material known as PTCDA, with height represented by the shading (white is taller, darker orange is lowest). The white scale bar represents 500 nanometers. The illustration at bottom is a representation of the crystal shape. Credit: Berkeley Lab, CU-Boulder

To achieve this imaging breakthrough, researchers from Berkeley Lab’s Advanced Light Source (ALS) and the University of Colorado-Boulder (CU-Boulder) combined the power of infrared light from the ALS and infrared light from a laser with a tool known as an atomic force microscope. The ALS, a synchrotron, produces light in a range of wavelengths or “colors” — from infrared to X-rays — by accelerating electron beams near the speed of light around bends.

The researchers focused both sources of infrared light onto the tip of the atomic force microscope, which works a bit like a record-player needle — it moves across the surface of a material and measures the subtlest of surface features as it lifts and dips.

The technique, detailed in a recent edition of the journal Science Advances, allows researchers to tune the infrared light in on specific chemical bonds and their arrangement in a sample, show detailed crystal features, and explore the nanoscale chemical environment in samples.

“Our technique is broadly applicable,” said Hans Bechtel an ALS scientist. “You could use this for many types of material — the only limitation is that it has to be relatively flat” so that the tip of the atomic force microscope can move across its peaks and valleys.

Markus Raschke, a CU-Boulder professor who developed the imaging technique with Eric Muller, a postdoctoral researcher in his group, said, “If you know the molecular composition and orientation in these organic materials then you can optimize their properties in a much more straightforward way.

“This work is informing materials design. The sensitivity of this technique is going from an average of millions of molecules to a few hundred, and the imaging resolution is going from the micron scale (millionths of an inch) to the nanoscale (billionths of an inch),” he said.

The infrared light of the synchrotron provided the essential wide band of the infrared spectrum, which makes it sensitive to many different chemicals’ bonds at the same time and also provides the sample’s molecular orientation. The conventional infrared laser, with its high power yet narrow range of infrared light, meanwhile, allowed researchers to zoom in on specific bonds to obtain very detailed imaging.

“Neither the ALS synchrotron nor the laser alone would have given us this level of microscopic insight,” Raschke said, while the combination of the two provided a powerful probe “greater than the sum of its parts.”

Raschke a decade ago first explored synchrotron-based infrared nano-spectroscopy using the BESSY synchrotron in Berlin. With his help and that of ALS scientists Michael Martin and Bechtel, the ALS in 2014 became the first synchrotron to offer nanoscale infrared imaging to visiting scientists.

The technique is particularly useful for the study and understanding of so-called “functional materials” that possess special photonic, electronic, or energy-conversion or energy-storage properties, he noted.

In principle, he added, the new advance in determining molecular orientation could be adapted to biological studies of proteins. “Molecular orientation is critical in determining biological function,” Raschke said. The orientation of molecules determines how energy and charge flows across from cell membranes to molecular solar energy conversion materials.

Bechtel said the infrared technique permits imaging resolution down to about 10-20 nanometers, which can resolve features up to 50,000 times smaller than a grain of sand.

The imaging technique used in these experiments, known as “scattering-type scanning near-field optical microscopy,” or s-SNOM, essentially uses the atomic force microscope tip as an ultrasensitive antenna, which transmits and receives focused infrared light in the region of the tip apex. Scattered light, captured from the tip as it moves over the sample, is recorded by a detector to produce high-resolution images.

“It’s non-invasive, and it provides information about molecular vibrations,” as the microscope’s tip moves over the sample, Bechtel said. Researchers used the technique to study the crystalline features of an organic semiconductor material known as PTCDA (perylenetetracarboxylic dianhydride).

Researchers reported that they observed defects in the orientation of the material’s crystal structure that provide a new understanding of the crystals’ growth mechanism and could aid in the design molecular devices using this material.

The new imaging capability sets the stage for a new National Science Foundation Center, announced in late September, that links CU-Boulder with Berkeley Lab, UC Berkeley, Florida International University, UC Irvine, and Fort Lewis College in Durango, Colo. The center will combine a range of microscopic imaging methods, including those that use electrons, X-rays, and light, across a broad range of disciplines.

This center, dubbed STROBE for Science and Technology Center on Real-Time Functional Imaging, will be led by Margaret Murnane, a distinguished professor at CU-Boulder, with Raschke serving as a co-lead.

At Berkeley Lab, STROBE will be served by a range of ALS capabilities, including the infrared beamlines managed by Bechtel and Martin and a new beamline dubbed COSMIC (for “coherent scattering and microscopy”). It will also benefit from Berkeley Lab-developed data analysis tools.

Less than a micrometre thin, bendable and giving all the colours that a regular LED display does, it still needs ten times less energy than a Kindle tablet. Researchers at Chalmers University of Technology have developed the basis for a new electronic “paper”. Their results were recently published in the high impact journal Advanced Materials.

Chalmers' e-paper contains gold, silver and PET plastic. The layer that produces the colours is less than a micrometre thin. Credit: Mats Tiborn

Chalmers’ e-paper contains gold, silver and PET plastic. The layer that produces the colours is less than a micrometre thin. Credit: Mats Tiborn

When Chalmers researcher Andreas Dahlin and his PhD student Kunli Xiong were working on placing conductive polymers on nanostructures, they discovered that the combination would be perfectly suited to creating electronic displays as thin as paper. A year later the results were ready for publication. A material that is less than a micrometre thin, flexible and giving all the colours that a standard LED display does.

“The ‘paper’ is similar to the Kindle tablet”, says Andreas Dahlin. “It isn’t lit up like a standard display, but rather reflects the external light which illuminates it. Therefore it works very well where there is bright light, such as out in the sun, in contrast to standard LED displays that work best in darkness. At the same time it needs only a tenth of the energy that a Kindle tablet uses, which itself uses much less energy than a tablet LED display”.

It all depends on the polymers’ ability to control how light is absorbed and reflected. The polymers that cover the whole surface lead the electric signals throughout the full display and create images in high resolution. The material is not yet ready for application, but the basis is there. The team has tested and built a few pixels. These use the same red, green and blue (RGB) colours that together can create all the colours in standard LED displays. The results so far have been positive, what remains now is to build pixels that cover an area as large as a display.

“We are working at a fundamental level but even so, the step to manufacturing a product out of it shouldn’t be too far away. What we need now are engineers”.

One obstacle today is that there is gold and silver in the display, which makes the manufacturing expensive.

“The gold surface is 20 nanometres thick so there is not that much gold in it”, says Andreas Dahlin. “But at present there is a lot of gold wasted in manufacturing it. Either we reduce the waste or we find another way to decrease the manufacturing cost”.

Andreas Dahlin thinks the best application for the displays will be well-lit places such as outside or in public places to display information. This could reduce the energy consumption and at the same time replace signs and information screens that aren’t currently electronic today with more flexible ones.

LED remains the dominant sapphire application in 2016. Overall, rates of usage in smartwatches have been disappointing and have decreased below 2015 levels. In parallel, smartphone display screen opportunities haven’t taken off. Within the highly competitive sapphire industry, players are chasing any opportunity to survive and optimize their cost structure. Prices seem to have reached bottom and stabilized after a rough ride over the last 12 months. After a dip in the second half of 2015, LED substrate demand has been growing strongly through 2016 and is now at record high levels, even triggering a limited shortage of high-quality 4″ materials and wafers. According to Yole Développement (Yole), the worldwide quarterly sapphire wafer consumption for LEDs has reached 28.5 million of TIE (Q3, 2016).

In its new report, Sapphire Market 2016: Substrates & Consumer Electronics Applications (September 2016, Yole Développement), Yole, the More than Moore market research and strategy consulting company, has analyzed the sapphire industry’s latest technology and market trends. Yole used a dedicated methodology based on both top-to-bottom and bottom-up approaches that included interviews across the entire value chain and a strong knowledge of the industry to review the status and prospects of sapphire technologies for LEDs, camera lenses, and fingerprint reader covers, as well as smartwatch and smartphone displays.

Once again this year, the consulting company collaborated with CIOE to present a powerful program at the International Forum on Sapphire Market & Technologies, 2nd edition (Shenzhen, China – Sept. 6 & 7, 2016 – Agenda). Sapphire industry leaders attended the conference and discussed the latest innovations and market challenges.

What is the status of the sapphire industry? After the 2014 crash, the episode with Apple, and GTAT’s bankruptcy, are there still some survivors? What are their today’s strategies? Beyond existing applications, could we expect emerging applications? Yole’s analysts offer you an overview of the current sapphire industry and announce 2017 trends.

The LED sector still has the highest demand for sapphire. However, Yole’s analysts confirm: the expected volumes cannot sustain the one hundred or so sapphire producers currently competing in the industry. As a consequence, some sapphire companies are leaving the most commoditized markets and shifting their development strategies toward niche markets with higher added-value such as medical, industrial, and military applications. Other business opportunities could materialize, including microLED arrays and other consumer applications. Meanwhile, lower quality production is being dumped on a large grey market serving a multitude of applications including optical, mechanical, industrial, watches, etc.

In Shenzhen, China, at the beginning of September, more than 100 executives gathered and discussed the sapphire industry’s status. With an impressive program including 18 presentations, multiple debates and networking sessions, the sapphire industry’s future was defined and analyzed by sapphire leaders. Yole and its partner CIOE collected good feedback from attendees and are already thinking about a 2017 session.

During this Forum, many relevant and exciting presentations took place, mainly focused on optimizing costs and identifying new markets. Dr. Eric Virey from Yole highlighted the sapphire industry, its latest technical and market trends with a special focus on emerging applications. (See Dr. Eric Virey presentation – 2nd Int. Forum on Sapphire Market & Technologies).

In the same session, leading sapphire manufacturers Monocrystal and Aurora Sapphire also reviewed their insights as key sapphire market players:

•  Mikhail Berest, VP of Sales at Monocrystal, detailed Monocrystal strategies: “The market is challenging not only for sapphire producers, but also for our customers. Our major focus is to strongly support our customers during this market storm by providing them with the highest quality product at a competitive price. We make this possible because Monocrystal’s sapphire is industry-leading due to its low internal stress and low etch pit density. This translates into longer LED lifetime and narrow wavelength distribution on our customers’ side…” (Full discussion on i-micronews, compound semi. news)

•  Xinhong Yang, VP & Technology Director, Aurora Sapphire, presented the latest technology innovations. He also focused his presentation on the future of the sapphire industry.

•  On the application side, Unionlight’s CTO, Huang XiaoWei, discussed military applications of sapphire in the last sapphire Forum session.

Reducing costs and improving quality were major topics discussed at the Forum. Fujian Jing’an Optoelectronics highlighted the importance of subsurface damages. Edouard Brunet, R&D Manager Grains & Powders Asia, Saint-Gobain High Performance Materials, introduced a 1-step polishing process with significant potential for cost reductions. Bernard Jones, VP of Technology & Product Development at Fametec, showed an innovative growth technology for large diameter LED wafers, and Ivan Orlov, Scientific Visual’s CEO, triggered extensive discussions after his presentation on automated ingot inspection and mapping equipment and standardization proposals.

“Once again, the International Forum on Sapphire Market & technologies brought together many players”,comments Jean-Christophe Eloy, President & CEO, Yole Développement. “It showed that in the difficult market environment we’ve experienced since late 2015, the industry needs to gather and exchange information in order to optimize ownership costs and enable new applications.”
Yole & CIOE’s sapphire Forum provided a great platform to stimulate discussion and new ideas with extensive networking opportunities for people and companies to find new partners for the next stage.

“The International Forum on Sapphire Market and Technologies is the key industry event for the main sapphire makers,” asserts Oleg Kachalov, CEO of Monocrystal.“For Monocrystal, it is a chance to meet long-term partners and experts and reach our customers with our new developments, which will allow them to strengthen their position in the LED market.”

“I was impressed by the quality of content presented at Yole & CIOE’s sapphire Forum 2016, which provided not only trend analysis but also deep insights”, says Margaret Connolly, VP of UBM Asia. “The event was well attended by the industry’s key decision makers. The collaboration between CIOE and Yole has been quite successful as the teams are committed to the common objective which is to support long term technology development and innovations. I look forward to attending the 2017 edition in Shenzhen.” UBM owns 100% of eMedia Asia, the majority owner of the annual CIOE.

What can we expect for 2017 and the years after?

Massive adoption of sapphire in display screens now seems unlikely. Many companies have partially or completely exited the industry over the last 12 months. Independent crystal growers in Korea such as DK-Aztek, OCI, and Unid LED have all stopped their sapphire activities. Historical players in Taiwan such as Tera-Xtal, Crystal Applied Technology or Procrystal appear to be on the verge of bankruptcy and U.S. leader Rubicon recently shut down its facility in Malaysia and exited the LED wafer market to refocus on the optical, industrial, and defense markets. But key players are still investing.

So, is there still hope for 2017? To answer that question, both Yole and CIOE are already working on a new sapphire Forum in 2017 in Shenzhen, China. Agenda & registration will be available soon. Stay tuned!

SEMICON Europa 2016, opening in less than two weeks in Grenoble, will explore the issues facing Europe’s semiconductor and electronics industries, including processes, materials, equipment and supply chain. SEMICON Europa (October 25-27) is a leading exhibition and conference dedicated to the future of electronics in Europe.

As semiconductor manufacturers target new high-growth European strength areas, SEMICON Europa connects the European ecosystem and the global manufacturing supply chain by offering new business opportunities like advanced packaging, MEMS, imaging, power electronics, flexible hybrid electronics, automotive, smart manufacturing, medtech and addressing the demands of the IoT.

Executive keynotes include:

  • GLOBALFOUNDRIES Dresden: “FDX and FinFET: Differentiated Technologies for Diverging Markets” presented by Dr. Rutger Wijburg, senior VP and GM
  • Intel Israel: “How Technology and Equipment March Forward Hand-in-Hand” presented by Maxine Fassberg, CEO
  • CEA-Leti: “European Chance in Industry and Technologies” presented by Marie-Noëlle Semeria, CEO

In addition, companies such as Infineon, STMicroelectronics, ABB, ASML, Applied Materials, SOITEC, imec and Fraunhofer, and hundreds more, will present the latest trends, technologies, processes and techniques in electronic applications, design and manufacturing.

This year for the first time, Iot Planet will co-locate with SEMICON Europa. The combined shows are expected to attract 7,000 professionals and more than 600 visiting companies, giving attendees the opportunity to conduct business up and down the supply chain.  New programs, like the B2B Matchmaking Event 2016, offer visitors and exhibitors an opportunity to prearrange appointments.

SEMICON Europa is co-located with 2016FLEX Europe which covers the field of large-scale electronics, with emphasis on printed, flexible and organic electronics and its convergence with conventional semiconductor manufacturing.

Register now and take advantage of our early pricing for conferences, forums, and select sessions. To register for SEMICON Europa 2016, please visit: www.semiconeuropa.org

Samsung Electronics Co., Ltd. today announced a new line-up of chip scale package (CSP) LED modules for spotlights and downlights that features color tunability and increased design compatibility.

LED_Image

“Our new CSP LED modules provide an optimal solution for lighting manufacturers who seek highly compatible and reliable LED components,” said Jacob Tarn, Executive Vice President, LED Business Team at Samsung Electronics. “Samsung will continue to strengthen its CSP technology leadership and spearhead new innovations in LED component technology to bring greater value to our customers.”

The new LED modules are Samsung’s first to incorporate CSP technology, which bring a wide range of lighting benefits such as significantly reducing the size of a conventional LED package. The combination of advanced flip chip and phosphor coating technology eliminates metal wires and plastic molds to enable more compact designs when manufacturing LED modules and fixtures.

In addition to their size advantage, Samsung’s new CSP LED modules deliver further characteristics that furnish seamless tunable color. A color-tunable LED module requires twice the number of LED packages in cool and warm temperature, which work in combination on the same board to create a range of tunable colors. In contrast to conventional plastic-molded LED packages that inevitably increase the size of the modules, Samsung’s ultra-compact chip scale LED packages allow the module size to remain unchanged.

Samsung’s new CSP LED modules are available in two form factors (19x19mm or 28x28mm) and are designed following Zhaga specifications, making them highly convenient in assembling. The modules also provide high-quality lighting in diverse beam angle options – spot, medium, wide – for improved compatibility with the optical solutions of Samsung’s partners. The new modules are based on CSP LED packages that have successfully completed 9,000 hours of LM-80 testing, a level of proven performance that reduces the time to market for lighting manufacturers.

Samsung is now sampling six models of the new CSP LED module in CRI 80 and 90 with varying lumen output, size and CCT specifications. The full line-up includes:

 Power

Form Factor 

Model

 Consumption

Lumen

(mm)

CCT
CO10 9.4 1050 lm 19×19 2700/3000/3500/4000K
CO20 18.3 2060 lm 19×19
CO30 27.4 3090 lm 28×28
CO40 36.5 4120 lm 28×28
TO10 9.2-9.8 1060 / 1150 lm 28×28

Color tunable between
2700K~5000K
TO20 17.7-18.4 1970 / 2190 lm 28×28

* Based on CRI 80