Category Archives: LEDs

Scientists with the Energy Department’s National Renewable Energy Laboratory (NREL) for the first time discovered how to make perovskite solar cells out of quantum dots and used the new material to convert sunlight to electricity with 10.77 percent efficiency.

The research, Quantum dot-induced phase stabilization of a-CsPbI3 perovskite for high-efficiency photovoltaics, appears in the journal Science. The authors are Abhishek Swarnkar, Ashley Marshall, Erin Sanehira, Boris Chernomordik, David Moore, Jeffrey Christians, and Joseph Luther from NREL. Tamoghna Chakrabarti from the Colorado School of Mines also is a co-author.

In addition to developing quantum dot perovskite solar cells, the researchers discovered a method to stabilize a crystal structure in an all-inorganic perovskite material at room temperature that was previously only favorable at high temperatures. The crystal phase of the inorganic material is more stable in quantum dots.

Most research into perovskites has centered on a hybrid organic-inorganic structure. Since research into perovskites for photovoltaics began in 2009, their efficiency of converting sunlight into electricity has climbed steadily and now shows greater than 22 percent power conversion efficiency. However, the organic component hasn’t been durable enough for the long-term use of perovskites as a solar cell.

NREL scientists turned to quantum dots-which are essentially nanocrystals-of cesium lead iodide (CsPbI3) to remove the unstable organic component and open the door to high-efficiency quantum dot optoelectronics that can be used in LED lights and photovoltaics.

The nanocrystals of CsPbI3 were synthesized through the addition of a Cs-oleate solution to a flask containing PbI2 precursor. The NREL researchers purified the nanocrystals using methyl acetate as an anti-solvent that removed excess unreacted precursors. This step turned out to be critical to increasing their stability.

Contrary to the bulk version of CsPbI3, the nanocrystals were found to be stable not only at temperatures exceeding 600 degrees Fahrenheit but also at room temperatures and at hundreds of degrees below zero. The bulk version of this material is unstable at room temperature, where photovoltaics normally operate and convert very quickly to an undesired crystal structure.

NREL scientists were able to transform the nanocrystals into a thin film by repeatedly dipping them into a methyl acetate solution, yielding a thickness between 100 and 400 nanometers. Used in a solar cell, the CsPbI3 nanocrystal film proved efficient at converting 10.77 percent of sunlight into electricity at an extraordinary high open circuit voltage. The efficiency is similar to record quantum dot solar cells of other materials and surpasses other reported all-inorganic perovskite solar cells.

The research was funded in part by the Energy Department’s Office of Science and by the SunShot Initiative.

NREL is the U.S. Department of Energy’s primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for the Energy Department by The Alliance for Sustainable Energy, LLC.

The SunShot Initiative is a collaborative national effort that aggressively drives innovation to make solar energy fully cost-competitive with traditional energy sources before the end of the decade. Through SunShot, the Energy Department supports efforts by private companies, universities, and national laboratories to drive down the cost of solar electricity to $0.06 per kilowatt-hour. Learn more at energy.gov/sunshot.

Researchers have designed a device that uses light to manipulate its mechanical properties. The device, which was fabricated using a plasmomechanical metamaterial, operates through a unique mechanism that couples its optical and mechanical resonances, enabling it to oscillate indefinitely using energy absorbed from light.

This is an optically-driven mechanical oscillator fabricated using a plasmomechanical metamaterial. Credit:  UC San Diego Jacobs School of Engineering

This is an optically-driven mechanical oscillator fabricated using a plasmomechanical metamaterial. Credit: UC San Diego Jacobs School of Engineering

This work demonstrates a metamaterial-based approach to develop an optically-driven mechanical oscillator. The device can potentially be used as a new frequency reference to accurately keep time in GPS, computers, wristwatches and other devices, researchers said. Other potential applications that could be derived from this metamaterial-based platform include high precision sensors and quantum transducers. The research was published Oct. 10 in the journal Nature Photonics.

Researchers engineered the metamaterial-based device by integrating tiny light absorbing nanoantennas onto nanomechanical oscillators. The study was led by Ertugrul Cubukcu, a professor of nanoengineering and electrical engineering at the University of California San Diego. The work, which Cubukcu started as a faculty member at the University of Pennsylvania and is continuing at the Jacobs School of Engineering at UC San Diego, demonstrates how efficient light-matter interactions can be utilized for applications in novel nanoscale devices.

Metamaterials are artificial materials that are engineered to exhibit exotic properties not found in nature. For example, metamaterials can be designed to manipulate light, sound and heat waves in ways that can’t typically be done with conventional materials.

Metamaterials are generally considered “lossy” because their metal components absorb light very efficiently. “The lossy trait of metamaterials is considered a nuisance in photonics applications and telecommunications systems, where you have to transmit a lot of power. We’re presenting a unique metamaterials approach by taking advantage of this lossy feature,” Cubukcu said.

The device in this study resembles a tiny capacitor–roughly the size of a quarter–consisting of two square plates measuring 500 microns by 500 microns. The top plate is a bilayer gold/silicon nitride membrane containing an array of cross-shaped slits–the nanoantennas–etched into the gold layer. The bottom plate is a metal reflector that is separated from the gold/silicon nitride bilayer by a three-micron-wide air gap.

When light is shined upon the device, the nanoantennas absorb all of the incoming radiation from light and convert that optical energy into heat. In response, the gold/silicon nitride bilayer bends because gold expands more than silicon nitride when heated. The bending of the bilayer alters the width of the air gap separating it from the metal reflector. This change in spacing causes the bilayer to absorb less light and as a result, the bilayer bends back to its original position. The bilayer can once again absorb all of the incoming light and the cycle repeats over and over again.

The device relies on a unique hybrid optical resonance known as the Fano resonance, which emerges as a result of the coupling between two distinct optical resonances of the metamaterial. The optical resonance can be tuned “at will” by applying a voltage.

The researchers also point out that because the plasmomechanical metamaterial can efficiently absorb light, it can function under a broad optical resonance. That means this metamaterial can potentially respond to a light source like an LED and won’t need a strong laser to provide the energy.

“Using plasmonic metamaterials, we were able to design and fabricate a device that can utilize light to amplify or dampen microscopic mechanical motion more powerfully than other devices that demonstrate these effects. Even a non-laser light source could still work on this device,” said Hai Zhu, a former graduate student in Cubukcu’s lab and first author of the study.

“Optical metamaterials enable the chip-level integration of functionalities such as light-focusing, spectral selectivity and polarization control that are usually performed by conventional optical components such as lenses, optical filters and polarizers. Our particular metamaterial-based approach can extend these effects across the electromagnetic spectrum,” said Fei Yi, a postdoctoral researcher who worked in Cubukcu’s lab.

Dialog Semiconductor plc (XETRA:DLG), a provider of highly integrated power management, AC/DC power conversion, solid state lighting (SSL) and Bluetooth(R) low energy technology, today announced the appointment of Mary Chan to the company’s Board of Directors, effective December 1, 2016.

“Mary’s significant international experience in the wireless communications sector will perfectly complement the existing rich mix of skills and perspectives on our Board,” said Rich Beyer, Chairman of the Board, Dialog Semiconductor. “Her particular insight into the ways connectivity and the Internet of Things (IoT) are driving change across multiple industries by enabling the delivery of cloud-based services on connected mobile platforms will be especially valuable.”

Ms. Chan’s career has spanned executive leadership roles at some of the world’s most successful international firms, including AT&T, Alcatel Lucent, Dell Inc. and General Motors Corporation (GM). Most recently at GM, Ms. Chan served between 2012 and 2015 as President, Global Connected Consumers & OnStar Service USA. In this role, Ms. Chan headed the organization responsible for the development of GM’s Global infotainment product and launching 4G LTE connectivity across GM’s global vehicle brands, successfully implementing new business models to improve the connected car and infotainment experience. At Dell, between 2009 and 2012, Ms. Chan led the company’s Enterprise Mobility Solutions and Services business in the USA. Prior to this, at Alcatel-Lucent, Ms. Chan served as Executive Vice President of the company’s US 4G LTE Wireless Networks business.

Ms. Chan currently serves as an Independent Director on the Board of SBA Communications Corporation, a leading operator and owner of wireless communications infrastructure across North, Central and South America. In addition, Ms. Chan is also currently the Managing Partner at VectoIQ which serves a number of companies in the area of smart transportation. Previously she also served on the Boards of the Mobile Marketing Association and CTIA – The Wireless Association. She holds both Bachelor and Master of Science degrees in Electrical Engineering from Columbia University.

Many LED failures are the result of voids or other gap-type anomalies that block heat flow from the die.

BY TOM ADAMS, Sonoscan,Inc., Elk Grove, IL

A few years ago, the only commercial class of LED devices – HB-LEDs – was typically manufactured for applications requiring high reliability. The goal in most applications was to have few field failures, or at least few early-term field failures. Most HB-LED appliances were consequently fairly expensive.

Recently, however, the world of commercial LEDs has split into two parts: High power LEDs, which continue the tradition of reliability and high brightness in appli- cations that require those characteristics, and mid power LEDs, which fill less demanding roles and tend to have lower initial costs. The principle behind mid power LEDS is that consumers will accept a somewhat higher failure rate in appliances having relatively large numbers of LEDs. The gradual loss of light output is balanced by the lower replacement cost.

Recent work has also shed light on the typical mechanisms of failure in both types of LEDs. Most failures in LEDs generally are related to power supply problems, but many failures are the result of voids or other gap-type anomalies that block heat flow from the die. Not surprisingly, there is good correlation between the total voided area beneath the die and the LED’s junction temperature.
Acoustic micro imaging, usually in an automated format, is widely used to ensure LED quality, but with some changes to accommodate the new lower-price market. LEDs can be inspected acoustically in wafer form, as singulated devices before lens placement, and after lens placement by pulsing ultrasound into the heat sink at the bottom of the device (in failure analysis, they may also be inspected by grinding down much of the lens and pulsing ultrasound from above).

The primary change is that singulated mid power LEDs destined for lower-priced applications often need less intensive acoustic inspection. A percentage of such LEDs may be placed in trays and scanned by a system such as one of Sonoscan’s C-SAM® tools, but this done as a non-destructive monitoring step to ensure that large numbers of defective devices are not slipping through rather than as 100% inspection to remove all defective devices. High power LEDs, however, may require 100% acoustic inspection.

The chief structural concerns in both midpower LEDs and high power LEDs are defects that are capable of blocking heat flow from the die. At a much lower power level, the situation is similar to that of IGBT modules, where heat from the die must reach a heat sink below the die to be dissipated. IGBTs generate far more heat than LEDs, but like IGBT modules both LED classes must dissipate heat downward. The lens above the LED is a very poor thermal transmitter.

In some designs the LED may be attached directly to the metal heat sink by a layer of solder. More often there is some type of printed circuit board between the die and the heat sink, with a thermal interface material (solder, grease, epoxy or an adhesive) between the die and the printed circuit board and between the printed circuit board and the heat sink.

Gap-type defects anywhere along the path from the die top the heat sink are the chief targets of acoustic imaging at these depths. A delamination or void as thin as 200Å will reflect virtually all of the ultrasound that strikes it; it is also a very efficient blocker of heat. The various gap-type defects have various somewhat overlapping names: a delamination suggests an interface that was once bonded but was somehow pulled apart; a void suggests a flattened (probably) air bubble; a non-bond suggests two surfaces that should have been bonded but never were, perhaps because of contamination of one of the surfaces. The actual etiology of a gap-type defect may more likely be revealed by knowledge of the processes used in packaging the LED than in observing the defect’s structure.

FIGURE 1 is a high-resolution acoustic image of the solder layer between the substrate and the heat sink of an LED. The transducer of the acoustic microimaging tool traveled back and forth just above this wafer at a speed that can exceed 1 m/s. Each second the transducer repeated its pulse-echo function thousands of times, pulsing ultra- sound into the wafer and receiving the return echoes from material interfaces – homogeneous materials generate no echoes. The amplitude of each echo is recorded, and will determine the pixel color for that x-y location. Most material interfaces are between two solids, reflect roughly 20% to 80% of the ultrasound, and in monochrome images produce dark gray to light gray pixels.

Screen Shot 2017-04-21 at 9.49.46 AM

In the polychromatic color map used here, only in the white areas is the solder bonded to both the substrate and the heat sink. Red regions are not bonded, and thus contain an air gap and reflect virtually all of the ultrasound. More than half of the intended contact area is not bonded, a situation that might be acceptable for a mid power LED, but not for a high power LED. If the non-bonded area grows in size — as they tend to do after thermal cycling — this LED may overheat and fail. If it is a mid power LED assembly, though, the failure of some units may have been anticipated and overall performance may remain within acceptable limits.

When ultrasound and heat encounter the interface between a solid and a void, they react in somewhat different ways. A pulse of ultrasound is almost entirely reflected, with no change in its velocity. Essentially none of the pulse crosses the interface. Heat too is reflected, but also retarded. None of the heat crosses the the gap by conduction, although some heat may cross the gap by convection if the gap is filled with air. If the heat is reflected into a heat-retentive material, that material will heat up.

FIGURE 2 is the acoustic image of a single high power LED from which most of the lens above the die has been ground away to permit a less distorted acoustic view of the die and the die substrate. There is still some distortion caused by the remaining lens material; the die is actually rectangular, for example. But the critical depth – the interface between the lens and the die substrate – is clearly visible. In the color map used here, red indicates the very high reflection from a gap-type defect or delam- ination, in this case the interface between a solid (the lens) and the air in the gap. Like the red regions in Fig. 1, this delamination reflects nearly 100% of the ultra- sound. What this image reveals, then, is that the lens is separated from the substrate by a gap. In itself, this delamination is relatively unimportant as a blocker of heat, because it lies beside and not below the die. But gaps such as this one tend to grow when exposed to thermal cycling; if this gap grows, it is likely to expand under the die and block significant heat. It if grows large enough, it can cause the die to overheat and fail.

Screen Shot 2017-04-21 at 9.49.52 AM

Both high power and mid power LEDs are also imaged acoustically in wafer form in order to find widespread defects as early as possible. FIGURE 3 shows one depth in one region of an HB-LED wafer. The circular or oval white areas formed as follows: at one point in the placing of layers on the wafer, small elongate structures broke free and moved away from their original positions. When the next layer was put down, these structures prevented some points on the layer from reaching the intended depth and thus caused a rounded air-filled void to form. The void is white where there is an interface between the air and the solid layer above. During later handling, smaller particles moved around in the free space of the void until they became trapped under the lower “ceiling” near the edge of the void. These particles form a broken ring around the particle that created the void. They are dark because the interface is between the solid “ceiling” and the solid particle.

Screen Shot 2017-04-21 at 9.49.59 AM

Solid State Technology announced today that its premier semiconductor manufacturing conference and networking event, The ConFab, will be held at the iconic Hotel del Coronado in San Diego on May 14-17, 2017. A 30% increase in attendance in 2016 with a similar uplift expected in 2017, makes the venue an ideal meeting location as The ConFab continues to expand.

    

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 collaborate on critical issues.

“The semiconductor industry is maturing, yet opportunities abound,” said Pete Singer, Editor-in-Chief of Solid State Technology and Conference Chair of The ConFab. “The Internet of Things (IoT) is exploding, which will result in a demand for “things” such as sensors and actuators, as well as cloud computing. 5G is also coming and will be the key technology for access to the cloud.”

The ConFab is the best place to seek a deeper understanding on these and other important issues, offering a unique blend of market insights, technology forecasts and strategic assessments of the challenges and opportunities 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,” Singer added.

Dave Mount

David Mount

Solid State Technology is 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 that 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 details on attending as a guest or qualifying as a VIP, contact Sally Bixby at [email protected].

By Zvi Or-Bach, President & CEO, MonolithIC 3D Inc.

As we have predicted two and a half years back, the industry is bifurcating, and just a few products pursue scaling to 7nm while the majority of designs stay on 28nm or older nodes.

Our March 2014 blog Moore’s Law has stopped at 28nm has recently been re-confirmed. At the time we wrote: “From this point on we will still be able to double the amount of transistors in a single device but not at lower cost. And, for most applications, the cost will actually go up.” This reconfirmation can be found in the following IBS cost analysis table slide, presented at the early Sept FD-SOI event in Shanghai.

Gate costs continue to rise each generation for FinFETs, IBS predicts.

Gate costs continue to rise each generation for FinFETs, IBS predicts.

As reported by EE Times – Chip Process War Heats Up, and quoting Handel Jones of IBS “28nm node is likely to be the biggest process of all through 2025”.

IBS prediction was seconded by “Samsung executive showed a foil saying it believes 28nm will have the lowest cost per transistor of any node.” The following chart was presented by Samsung at the recent SEMICON West (2016).

Zvi 2

And even Intel has given up on its “every two years” but still claims it can keep reducing transistor cost. Yet Intel’s underwhelming successes as a foundry suggests otherwise. We have discussed it in a blog titled Intel — The Litmus Test, and it was essentially repeated by SemiWiki’s Apple will NEVER use Intel Custom Foundry!

This discussion seems academic now, as the actual engineering costs of devices in advanced nodes have shown themselves to be too expensive for much of the industry. Consequently, and as predicted, the industry is bifurcating, with a few products pursuing scaling to 7nm while the majority of designs use 28nm or older nodes.

The following chart derived from TSMC quarterly earnings reports was published last week by Ed Sperling in the blog Stepping Back From Scaling:

Zvi 3

Yes, the 50-year march of Moore’s Law has ended, and the industry is now facing a new reality.

This is good news for innovation, as a diversity of choices helps support new ideas and new technologies such as 3D NAND, FDSOI, MEMS and others. These technologies will enable new markets and products such as the emerging market of IoT.

A good opportunity to learn more about these new scaling technologies is the IEEE S3S ’16, to be held in the Hyatt Regency San Francisco Airport, October 10th thru 13th, 2016. It starts with 3D and FDSOI tutorials, the emerging technologies for the IC future. CEA Leti is scheduled to give an update on their CoolCube program, Qualcomm will present some of their work on monolithic 3D, and three leading researchers from an imec, MIT, and Korea university collaboration will present their work on advanced monolithic 3D integration technologies. Many other authors will discuss their work on monolithic 3DIC and its ecosystem, in addition to tracks focused on SOI, sub-VT and dedicated sessions on IoT.

SEMI today announced that twenty-one start-ups have been selected to pitch to investors and exhibit their products at SEMICON Europa‘s INNOVATION VILLAGE in Grenoble, France at the Alpexpo from 25-27 October, 2016. INNOVATION VILLAGE will showcase never-before-seen technologies, with early stage companies introducing their technologies on the exposition floor.

INNOVATION VILLAGE, an area of more than 400m² on the SEMICON Europa exhibition floor, is dedicated to the launch and promotion of technological innovation.  Twenty-one leading European start-ups will be featured, including:

• 3Dis Technologies • HPROB • ProNT GmbH
• Antaios • Irlynx • Silicon Radar
• Applied Nanolayers BV • Madci • Siltectra
• Bright Red Systems Gmbh • Mi2-factory GmbH • Smart Force Technologies
• Fastree3D • Miniswys SA • Smoltek
• FlexEnable • Noivion • Solayl
• FMC – The Ferroelectric Memory Company • Pollen Metrology • Terabee

Start-ups will be given the opportunity to “pitch” their products to potential investors including Applied Ventures LLC, Samsung Ventures, TEL Venture Capital, Robert Bosch Venture Capital GmbH, 3M New Ventures, Aliad-Air Liquide Corporate Venture Capital, Capital ASTER, CEA Investment, VTT Ventures, Capital-E, Siemens Technology Accelerator GmbH and more.

For the first time at the INNOVATION VILLAGE, a new technology transfer program, called the TechnoMarket, from partner Linksium, SATT Grenoble Alpes will be showcased on 26 October. “The national network, SATT, has chosen SEMICON Europa to promote the best technological projects derived from public research within France that can also benefit manufacturers. The new Techno Market event offers new opportunities for businesses,” says Gilles Talbotier, CEO, Linksium.  The TechnoMarket acts as a genuine market place for VCs and companies ready to invest in innovation.

Free admission code: Use the promotional code SCEU-TBN4U to gain free admission to the show floor (not including conferences or forums).  Register now – attend to connect.

For more information about SEMICON Europa, please visit http://www.semiconeuropa.org

SEMI, a supplier of independent semiconductor market research, today announced SEMI FabView, a mobile-friendly, interactive version of its popular World Fab Forecast quarterly report for electronic supply chain players and analysts. The new product was announced during the press conference at SEMICON Taiwan, where 43,000 industry professionals are convening this week. SEMI FabView tracks spending and capacities of over 1,100 facilities, including over 60 future facilities, across industry segments from Analog, Power, Logic, MPU, Memory, and Foundry to MEMS and LED fabs.

semi fabview

SEMI FabView features high-level fab data such as capacity, technology nodes, and equipment spending, with other device manufacturing insights such as fabs by region, wafer size, product type and construction status. This new online platform enables anytime access on the changes taking place in fab construction and expansion, production volume, device types, and more. The ability to quickly access the latest data for quarterly business reviews or earnings calls, or to validate an investment decision, is a key feature of this new product.

“SEMI FabView, an online platform, provides SEMI members and customers access to the industry benchmark World Fab Forecast database information in an entirely new way,” said Dan Tracy, senior director of SEMI Industry Research & Statistics for SEMI. “By adding the interactive elements of SEMI FabView, subscribers now have on-the-go real-time access to expert analysis that can be implemented in their models or forecasts.”

SEMI FabView users can:

  • view forecast for equipment and construction spending, capacity changes, and fab status from new plans to closures
  • organize data views by filtering data and accessing analyst commentary for each company and fab to see the latest SEMI forecast
  • access forecast data by company, geographical region, wafer size, technology geometry and specific stages of fab life cycle ─ from announced and planned new fabs to fabs that are in transition (e.g., when a cleanroom is converting to a larger wafer size or a different product type)

SEMI FabView is available for a product demo; contact [email protected]. Learn more about SEMI FabView here: www.semi.org/en/semi-fabview

“Promising” and “remarkable” are two words U.S. Department of Energy’s Ames Laboratory scientist Javier Vela uses to describe recent research results on organolead mixed-halide perovskites.

Perovskites are optically active, semiconducting compounds that are known to display intriguing electronic, light-emitting and chemical properties. Over the last few years, lead-halide perovskites have become one of the most promising semiconductors for solar cells due to their low cost, easier processability and high power conversion efficiencies. Photovoltaics made of these materials now reach power conversion efficiencies of more than 20 percent.

Vela’s research has focused on mixed-halide perovskites. Halides are simple and abundant, negatively charged compounds, such as iodide, bromide and chloride. Mixed-halide perovskites are of interest over single-halide perovskites for a variety of reasons. Mixed-halide perovskites appear to benefit from enhanced thermal and moisture stability, which makes them degrade less quickly than single-halide perovskites, Vela said. He added they can be fine-tuned to absorb sunlight at specific wavelengths, which makes them useful for tandem solar cells and many other applications, including light emitting diodes (LEDs).Using these compounds, scientists can control the color and efficiency of such energy conversion devices.

Speculating that these enhancements had something to do with the internal structure of mixed-halide perovskites, Vela, who is also an associate professor of chemistry at Iowa State University (ISU), worked with scientists with expertise in solid-state nuclear magnetic resonance (NMR) at both Ames Laboratory and ISU. NMR is an analytical chemistry technique that provides scientists with physical, chemical, structural and electronic information about complex samples.

“Our basic question was what it is about these materials in terms of their chemistry, composition, and structure that can affect their behavior,” said Vela.

Scientists found that depending on how the material is made there can be significant nonstoichiometric impurities or “dopants” permeating the material, which could significantly affect the material’s chemistry, moisture stability and transport properties.

The answers came via the combination of the use of optical absorption spectroscopy, powder X-ray diffraction and for the first time, the advanced probing capabilities of lead solid-state NMR.

“We were only able to see these dopants, along with other semicrystalline impurities, through the use of lead solid-state NMR,” said Vela.

Another major discovery scientists made was that solid state synthesis is far superior to solution-phase synthesis in making mixed-halide perovskites. According to Vela, the advanced spectroscopy and materials capabilities of Ames Laboratory and ISU were critical in understanding how various synthetic procedures affect the true composition, speciation, stability and optoelectronic properties of these materials.

“We found you can make clean mixed halide perovskites without semi-crystalline impurities if you make them in the absence of a solvent,” Vela said.

According to Vela, the significance of their findings is multifold and they are only beginning to grasp the implications of those findings.

“One obvious implication is that our understanding of the amazing opto-electronic properties of these semiconductors was incomplete,” said Vela. “We’re dealing with a compound that is not inherently as simple as people thought.”

The research is further discussed in a paper, “Persistent Dopants and Phase Segregation in Organolead Mixed-Halide Perovskites,” authored by Vela, Bryan A. Rosales, Long Men, Sarah D. Cady, Michael P. Hanrahan, and Aaron J. Rossini; and published online in Chemistry Materials. The work was supported by DOE’s Office of Science.

By Christian G. Dieseldorff, Industry Research & Statistics Group at SEMI (September 6, 2016)

SEMI’s Industry Research and Statistics group has published its August update of the World Fab Forecast report. The report has served the industry for 24 years, observing and analyzing spending, capacity, and technology changes for all front-end facilities worldwide, from high-volume to R&D fabs.  SEMI’s latest data show increasing equipment spending, reaching 4.1 percent YOY in 2016 and 10.6 percent in 2017. Figure 1 (below) shows a forecast of  -2 percent decline from 2H2015 to 1H2016 and an 18 percent increase from 1H2016 to. 2H2016.

Figure 1: Fab Equipment Spending by Quarter

Figure 1: Fab Equipment Spending by Quarter

The largest growth drivers for the industry are mobile devices (including devices using SSDs), automotive, and soon anticipated to be IoT, with these applications, in many cases, requiring 3D NAND and Logic 10nm/7nm.

The SEMI report indicates that the two industry segments leading to the biggest increase in 2H16 are Foundry (29 percent) and Memory (21 percent).  Growth in Memory is driven by a significant increase in 3D NAND spending in 2016. Comparing 2016 to 2017, Foundry growth remains quite steady, with a 14 percent increase in 2016 and 13 percent in 2017.

Companies like Samsung, Micron, Flash Alliance, Intel, and SK Hynix drive Memory growth with 3D NAND to an astounding 152 percent increase in 2016 and 29 percent in 2017. However, utilization of all this equipment is still low in 2016 but is expected to increase in 2017.

Looking at other product segments, DRAM equipment spending is expected to decline by 31 percent in 2016 and then recover slightly with 2 percent growth in 2017. Power devices also show strong growth with 25 percent in 2016 and 16 percent in 2017. The Analog segment will slump by -15 percent in 2016 but increase by 20 percent in 2017. Similarly, MPU will drop -20 percent in 2016 and then is expected to increase by 48 percent in 2017.

Comparing spending by region in 2016, SE Asia shows the largest growth, with 157 percent in 2016, driven mainly by 3D NAND (see Figure 2).

China, in third place for overall spending, shows 64 percent growth for 2016 primarily due to 3D NAND by non-Chinese companies, closely followed by Foundry companies. Although the largest spenders in China currently are overseas device companies, China-based chipmakers are starting to pick up investment activity.

Figure 2: Fab Equipment Spending by Region

Figure 2: Fab Equipment Spending by Region

By contrast, the largest growth rate in 2017 is in Europe/Mideast with about 60 percent which is mainly due to ramping of 10nm facilities. Korea is in second place for total spending, mainly driven by Samsung’s investment in DRAM and Flash. Japan in third place driven by Flash Alliance (3D NAND).

The World Fab Forecast report provides more detailed information by company and fab for construction spending, equipment spending and capacities by region and product type.  Since the last publication in May 2016, the SEMI research team has made over 330 changes to 300 facilities/lines. This includes 27 new records and 18 records closed.

For information about semiconductor manufacturing for the remainder of 2016 and in 2017, and for details about capex for construction projects, fab equipping, technology levels, and products, order the SEMI World Fab Forecast Report. The report, in Excel format, tracks spending and capacities for over 1,100 facilities including over 82 future facilities, across industry segments from Analog, Power, Logic, MPU, Memory, and Foundry to MEMS and LEDs facilities.  Using a bottoms-up approach methodology, the SEMI Fab Forecast provides high-level summaries and graphs, and in-depth analyses of capital expenditures, capacities, technology and products by fab.

The SEMI Worldwide Semiconductor Equipment Market Subscription (WWSEMS) data tracks only new equipment for fabs and test and assembly and packaging houses.  The SEMI World Fab Forecast and its related Fab Database reports track any equipment needed to ramp fabs, upgrade technology nodes, and expand or change wafer size, including new equipment, used equipment, or in-house equipment. Also check out the Opto/LED Fab Forecast. Learn more about the SEMI fab databases at: www.semi.org/MarketInfo/FabDatabase and www.youtube.com/user/SEMImktstats