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A nanostructured gate dielectric may have addressed the most significant obstacle to expanding the use of organic semiconductors for thin-film transistors. The structure, composed of a fluoropolymer layer followed by a nanolaminate made from two metal oxide materials, serves as gate dielectric and simultaneously protects the organic semiconductor – which had previously been vulnerable to damage from the ambient environment – and enables the transistors to operate with unprecedented stability.

Image shows organic-thin film transistors with a nanostructured gate dielectric under continuous testing on a probe station. (Credit: Rob Felt, Georgia Tech)

Image shows organic-thin film transistors with a nanostructured gate dielectric under continuous testing on a probe station. (Credit: Rob Felt, Georgia Tech)

The new structure gives thin-film transistors stability comparable to those made with inorganic materials, allowing them to operate in ambient conditions – even underwater. Organic thin-film transistors can be made inexpensively at low temperature on a variety of flexible substrates using techniques such as inkjet printing, potentially opening new applications that take advantage of simple, additive fabrication processes.

“We have now proven a geometry that yields lifetime performance that for the first time establish that organic circuits can be as stable as devices produced with conventional inorganic technologies,” said Bernard Kippelen, the Joseph M. Pettit professor in Georgia Tech’s School of Electrical and Computer Engineering (ECE) and director of Georgia Tech’s Center for Organic Photonics and Electronics (COPE). “This could be the tipping point for organic thin-film transistors, addressing long-standing concerns about the stability of organic-based printable devices.”

The research was reported January 12 in the journal Science Advances. The research is the culmination of 15 years of development within COPE and was supported by sponsors including the Office of Naval Research, the Air Force Office of Scientific Research, and the National Nuclear Security Administration.

Transistors comprise three electrodes. The source and drain electrodes pass current to create the “on” state, but only when a voltage is applied to the gate electrode, which is separated from the organic semiconductor material by a thin dielectric layer. A unique aspect of the architecture developed at Georgia Tech is that this dielectric layer uses two components, a fluoropolymer and a metal-oxide layer.

“When we first developed this architecture, this metal oxide layer was aluminum oxide, which is susceptible to damage from humidity,” said Canek Fuentes-Hernandez, a senior research scientist and coauthor of the paper. “Working in collaboration with Georgia Tech Professor Samuel Graham, we developed complex nanolaminate barriers which could be produced at temperatures below 110 degrees Celsius and that when used as gate dielectric, enabled transistors to sustain being immersed in water near its boiling point.”

The new Georgia Tech architecture uses alternating layers of aluminum oxide and hafnium oxide – five layers of one, then five layers of the other, repeated 30 times atop the fluoropolymer – to make the dielectric. The oxide layers are produced with atomic layer deposition (ALD). The nanolaminate, which ends up being about 50 nanometers thick, is virtually immune to the effects of humidity.

“While we knew this architecture yielded good barrier properties, we were blown away by how stably transistors operated with the new architecture,” said Fuentes-Hernandez. “The performance of these transistors remained virtually unchanged even when we operated them for hundreds of hours and at elevated temperatures of 75 degrees Celsius. This was by far the most stable organic-based transistor we had ever fabricated.”

For the laboratory demonstration, the researchers used a glass substrate, but many other flexible materials – including polymers and even paper – could also be used.

In the lab, the researchers used standard ALD growth techniques to produce the nanolaminate. But newer processes referred to as spatial ALD – utilizing multiple heads with nozzles delivering the precursors – could accelerate production and allow the devices to be scaled up in size. “ALD has now reached a level of maturity at which it has become a scalable industrial process, and we think this will allow a new phase in the development of organic thin-film transistors,” Kippelen said.

An obvious application is for the transistors that control pixels in organic light-emitting displays (OLEDs) used in such devices as the iPhone X and Samsung phones. These pixels are now controlled by transistors fabricated with conventional inorganic semiconductors, but with the additional stability provided by the new nanolaminate, they could perhaps be made with printable organic thin-film transistors instead.

Internet of things (IoT) devices could also benefit from fabrication enabled by the new technology, allowing production with inkjet printers and other low-cost printing and coating processes. The nanolaminate technique could also allow development of inexpensive paper-based devices, such as smart tickets, that would use antennas, displays and memory fabricated on paper through low-cost processes.

But the most dramatic applications could be in very large flexible displays that could be rolled up when not in use.

“We will get better image quality, larger size and better resolution,” Kippelen said. “As these screens become larger, the rigid form factor of conventional displays will be a limitation. Low processing temperature carbon-based technology will allow the screen to be rolled up, making it easy to carry around and less susceptible to damage.

For their demonstration, Kippelen’s team – which also includes Xiaojia Jia, Cheng-Yin Wang and Youngrak Park – used a model organic semiconductor. The material has well-known properties, but with carrier mobility values of 1.6 cm2/Vs isn’t the fastest available. As a next step, they researchers would like to test their process on newer organic semiconductors that provide higher charge mobility. They also plan to continue testing the nanolaminate under different bending conditions, across longer time periods, and in other device platforms such as photodetectors.

Though the carbon-based electronics are expanding their device capabilities, traditional materials like silicon have nothing to fear.

“When it comes to high speeds, crystalline materials like silicon or gallium nitride will certainly have a bright and very long future,” said Kippelen. “But for many future printed applications, a combination of the latest organic semiconductor with higher charge mobility and the nanostructured gate dielectric will provide a very powerful device technology.”

A discovery by an international team of researchers from Princeton University, the Georgia Institute of Technology and Humboldt University in Berlin points the way to more widespread use of an advanced technology generally known as organic electronics.

The research, published in the journal Nature Materials, focused on organic semiconductors, a class of materials prized for their applications in emerging technologies such as flexible electronics, solar energy conversion, and high-quality color displays for smartphones and televisions. In the short term, the advancement could particularly help with organic light-emitting diodes that operate at high energy to emit colors such as green and blue.

Researchers used ultraviolet light to excite molecules in a semiconductor, triggering reactions that split up and activated a dopant. Credit: Princeton University / Jing Wang and Xin Lin

Researchers used ultraviolet light to excite molecules in a semiconductor, triggering reactions that split up and activated a dopant. Credit: Princeton University / Jing Wang and Xin Lin

“Organic semiconductors are ideal materials for the fabrication of mechanically flexible devices with energy-saving, low-temperature processes,” said Xin Lin, a doctoral student and a member of the Princeton research team. “One of their major disadvantages has been their relatively poor electrical conductivity. In some applications, this can lead to difficulties and inefficient devices. We are working to improve the electrical properties of organic semiconductors.”

Semiconductors, typically made of silicon, are the foundation of modern electronics because engineers can take advantage of their unique properties to control electrical currents. Among many applications, semiconductor devices are used for computing, signal amplification, and switching. They are used in energy-saving devices such as light-emitting diodes and devices that convert energy such as solar cells.

Essential to these functionalities is a process called doping, in which the semiconductor’s chemical makeup is modified by adding a small amount of chemicals or impurities. By carefully choosing the type and amount of dopant, researchers can alter semiconductors’ electronic structure and electrical behavior in a variety of ways.

In their Nature Materials paper, the researchers have described a new approach for greatly increasing the conductivity of organic semiconductors, formed of carbon-based molecules rather than silicon atoms. The dopant, a ruthenium-containing compound, was a reducing agent, which means it added electrons to the organic semiconductor as part of the doping process. The addition of the electrons was the key to increasing the semiconductor’s conductivity. The compound belongs to a newly-introduced class of dopants called dimeric organometallic dopants. Unlike many other powerful reducing agents, these dopants are stable when exposed to air but still work as strong electron donors both in solution and solid state.

Georgia Tech’s Seth Marder, a Regents Professor in the School of Chemistry and Biochemistry, and Stephen Barlow, a research scientist in the school, led the development of the new dopant. They called the ruthenium compound a “hyper-reducing dopant.”

They said it was unusual, not only in its combination of electron donation strength and air stability but also in its ability to work with a class of organic semiconductors that have previously been very difficult to dope. In studies conducted at Princeton, the researchers found that the new dopant increased the conductivity of these semiconductors by about a million times.

The ruthenium compound was a dimer, meaning it consisted of two identical molecules, or monomers, connected by a chemical bond.  As is, the compound proved relatively stable and, when added to these difficult-to-dope semiconductors, it did not react and remained in its equilibrium state. That posed a problem because to increase the conductivity of the organic semiconductor, the ruthenium dimer needed to split and release its two identical monomers.

Princeton’s Lin, the study’s lead author, said the researchers looked for different ways to break up the ruthenium dimer and activate the doping. Eventually, he and Berthold Wegner, a visiting graduate student from the group of Norbert Koch at Humboldt University, took a hint from how photosynthetic systems work. They irradiated the system with ultraviolet light, which excited molecules in the semiconductor and initiated the reaction. Under exposure to the light, the dimers were able to dope the semiconductor, leading to a roughly 100,000 times increase in the conductivity.

After that, the researchers made an interesting observation.

“Once the light was turned off, one might naively expect the reverse reaction to occur and the increased conductivity to disappear,” said Georgia Tech’s Marder, who is also associate director of the Center for Organic Photonics and Electronics (COPE) at Georgia Tech. “However, this was not the case.”

The researchers found that the ruthenium monomers remained isolated in the semiconductor, increasing conductivity, even though thermodynamics should have returned the molecules to their original configuration as dimers. Antoine Kahn, a Princeton professor who led the research team, said the physical layout of the molecules inside the doped semiconductor provides a likely answer to this puzzle. The hypothesis is that the monomers are scattered in the semiconductor in such a way that it was very difficult for them to return to their original configuration and re-form the ruthenium dimer. To recombine, he said, the monomers would have to have faced in the correct orientation, but in the mixture, they remained askew. So, even though thermodynamics showed that dimers should reform, most never snapped back together.

“The question is why aren’t these things moving back together into equilibrium,” said Kahn, who is Stephen C. Macaleer ’63 Professor in Engineering and Applied Science. “The answer is they are kinetically trapped.”

In fact, the researchers observed the doped semiconductor for over a year and found very little decrease in the electrical conductivity. Also, by observing the material in light-emitting diodes fabricated by the group of Barry Rand, an assistant professor of electrical engineering at Princeton and the Andlinger Center for Energy and the Environment, the researchers discovered that doping was continuously re-activated by the light produced by the device.

“The light activates the system more, which leads to more light production and more activation until the system is fully activated, said Marder, who is Georgia Power Chair in Energy Efficiency. “This alone is a novel and surprising observation.”

The paper was co-authored by Kyung Min Lee, Michael A. Fusella, and Fengyu Zhang, of Princeton, and Karttikay Moudgil of Georgia Tech. Research was funded by the National Science Foundation (grants DMR-1506097, DMR-1305247), the Department of Energy’s Energy Efficiency & Renewable Energy Solid-State Lighting program (award DE-EE0006672) and the DoE’s Office of Basic Energy Sciences, Division of Materials Sciences and Engineering (award DE-SC0012458), the Deutsche Forschungsgemeinschaft (project SFB 951) and the Helmholtz Energy-Alliance Hybrid Photovoltaics project.

At CES 2018, PixelDisplay will be demonstrating Vivid Color HDR, and implementations for thinner, more portable, brighter, narrow-bezel, cost-effective display products, targeting new HDR standards, with:

  • Increased color gamut and brightness, with better energy efficiency and lower cost, thickness, and weight than previously available
  • Wider-gamut color, for brighter edge-lit HDR LCD’s without the limitations of Quantum Dots, or HDR-crippling narrow-band phosphors
  • Thin MiniLED 2D array direct-backlit for HDR LCD’s, enabling removal of diffuser and light-guide layers, for additional savings
  • Flexible capabilities: “In-die” standard LED applications, “Roll-to-roll” color-conversion layers for MiniLED, and “Wafer-level-patterning” for MicroLED displays
  • Highest compatibility with LCD manufacturing processes, enabling existing LED Backlight designs to meet the new HDR standards
  • Zero heavy metals. Fully RoHS compliant

Following the initial launch of Vivid Color technology May 2017, demonstrated in the Innovation-Zone of SID’s DisplayWeek Conference in LA, showing an industry leading 97.8% of Rec.2020 from a single chip LED, PixelDisplay is directly addressing the HDR market gaps unfilled by Narrow-Band Phosphors, and Quantum Dots.

Mike Trainor, VP of Marketing at PixelDisplay, commented, “We’ve already established our capability for industry-leading laser-like color purity for AR and the next generation 8K standards, but the opportunity we also conveyed in our presentations and SID paper at DisplayWeek was the ability to apply the Vivid Color technology to nearer-term products aiming for prolific HDR compatibility, in thin, portable and narrow-bezel product categories.” Trainor continued, “We’re proud to be showing how near-term this technology is, through side-by-side comparisons with QLED LCD display, and LCD using our entry-level Vivid Color VC65R, the first of the new product series.”

Mike Trainor summarized, “Vivid Color is unique in enabling existing LCD display designs aiming to achieve the UHD Alliance’s MobileHDR and VESA’s new DisplayHDR logo’s requirements, without thickness-adding, bezel-widening. And unlike Narrow-Band KSF Phosphor LED’s, Vivid Color is fully HDR-Compatible, directly supporting inter-frame and dynamic PWM backlight control at high speeds, and very high brightness without disrupting color, sacrificing responsiveness or dynamic range – key challenges of these new HDR standards.”

By Inna Skvortsova, SEMI

Electromagnetic interference (EMI) is an increasingly important topic across the global electronics manufacturing supply chain.  Progressively smaller geometries of ICs, lower supply voltages, and higher data rates all make devices and processes more vulnerable to EMI. Electrical noise, EMI-induced signal generated by equipment, and factors such as power line transients affect manufacturing processes, from wafer handling to wire bonding to PCB assembly and test, causing millions of dollars in losses to the industry. Furthermore, conducted emission capable of causing electrical overstress (EOS) can damage sensitive semiconductor devices.  Intel consistently names EOS as the “number one source of damage to IC components.” (Intel® Manufacturing Enabling Guide 2001, 2010, 2016).

While EMC (Electromagnetic Compatibility) standards, such as the European EMC Directive and FCC Testing and Certification, etc. provide limits on allowed emission levels of equipment, once the equipment is installed along with other tools, the EMI levels in actual operating environments can be substantially different and therefore impact the equipment operation, performance, and reliability. For example, (i) Occasional transients induce “extra” pulses in rotary feedback of the servo motor which in time contributes to robotic arm’s erroneous position eventually damaging the wafer; (ii) Combination of high-frequency noise from servo motors and switched mode power supplies in the tool creates difference in voltage between the bonding wire/funnel and the device which causes high current and eventual electrical overstress to the devices; (iii) Wafer probe test provides inconsistent results due to high level of EMI on the wafer chuck caused by a combination of several servo motors in the wafer handler.  Field cases like these illustrate the gap between EMC test requirements and real-life EMI tolerance levels and its impact on semiconductor manufacturing and handling.

EMI on AC power lines

EMI on AC power lines

New standard, SEMI E176-1017, Guide to Assess and Minimize Electromagnetic Interference (EMI) in a Semiconductor Manufacturing Environment, developed by the NA Chapter of the Global Metrics Technical Committee bridges this gap. Targeted to IC manufacturers and anyone handling semiconductor devices, such as PCB assembly and integration of electronic devices, SEMI E176 is a practical guide as well as an educational document. SEMI E176 provides a concise summary of EMI origins, EMI propagation, measurement techniques and recommendations on mitigation of undesirable electromagnetic emission to enable equipment co-existence and proper operation as well as reduction of EOS in its intended usage environment. Specifically, E176 provides recommended levels for different types of EMI based on IC geometries.

“SEMI E176 is likely the only active Standard in the entire industry providing recommendations on both acceptable levels of EMI in manufacturing environments and the means of achieving and maintaining these numbers,” said Vladimir Kraz, co-Chair of the NA Metrics Technical Committee and president of OnFILTER, Inc. “E176 is also unique because it is not limited just to semiconductor manufacturing, but has application across other industries.  Back-end assembly and test, as well as PCB assembly are just as affected by EMI and can benefit from SEMI E176 implementation as there are strong similarities between handling of semiconductor devices in IC manufacturing and in PCB assemblies and prevention of defects is often shared between IC and PCBA manufacturers.”

The newly published SEMI E176 and recently updated SEMI E33-0217, Guide for Semiconductor Manufacturing Equipment Electromagnetic Compatibility (EMC),provide complete documentation for establishing and maintaining low EMI levels in the manufacturing environment.

Undesirable emission has operational, liability and regulatory consequences.  Taming it is a challenging task and requires a comprehensive approach that starts from proper system design practices and ends with developing EMI expertise in the field.  The new SEMI 176 provides practical guidance on reducing EMI to the levels necessary for effective high yield semiconductor manufacturing today and in the future.

SEMI Standards development activities take place throughout the year in all major manufacturing regions. To get involved, join the SEMI International Standards Program at: www.semi.org/standardsmembership.

 

See-through electronic devices, such as transparent displays, smart windows and concealed circuits require completely translucent components if users are to digitally interact with their perceived surroundings and manipulate this information in real time. Now, KAUST researchers have devised a strategy that helps to integrate transparent conducting metal-oxide contacts with two-dimensional (2D) semiconductors into these devices.

Ultrathin semiconductor sheets that are composed of transition metals associated with chalcogen atoms, such as sulfur, selenium and tellurium, present exceptional electronic properties and optical transparency. However, to date, incorporating molybdenum sulphide (MoS2) monolayers into circuits has relied on silicon substrates and metal electrodes, such as gold and aluminum. The opacity of these materials has stalled attempts to develop fully transparent 2D electronic devices.

The KAUST team led by material scientists Xi-Xiang Zhang and Husam Alshareef has combined MoS2 monolayers with transparent contacts to generate a series of devices and circuits, such as transistors, inverters, rectifiers and sensors. The contacts consisted of aluminum-doped zinc oxide (AZO), a low-cost transparent and electrically conductive material that may soon replace the widely used indium-tin oxide. “We wanted to capitalize on the excellent electronic properties of 2D materials, while retaining full transparency in the circuits,” explains Alshareef.

According to Alshareef, the researchers grew the contacts over a large area by atomic-layer deposition, during which individual atom layers precisely accumulate on a substrate. Their main difficulty was to also form high-quality MoS2 monolayers on silicon-based substrates over a large area. “We overcame this by using an interfacial layer that promotes MoS2 growth,” says Alshareef.

The team also developed a water-based transfer process that moves the as-deposited large-area monolayers onto a different substrate, such as glass or plastic. The researchers then deposited the AZO contacts on the transferred 2D sheets before manufacturing the devices and circuits.

The resulting devices outperformed their equivalents equipped with opaque metal contacts, such as gate, source and drain electrodes, which demonstrates the high compatibility between transparent conducting metal-oxide contacts and MoS2 monolayers. “The transistors fabricated by the large-area process showed the lowest turn-on voltage of any reported MoS2 monolayer-based thin-film transistor grown by chemical vapor deposition,” says PhD student Zhenwei Wang, first author of the study.

“Additional circuits are planned that will help demonstrate that our approach is robust and scalable” says Alshareef.

Researchers at the University of Liverpool have made a discovery that could improve the conductivity of a type of glass coating which is used on items such as touch screens, solar cells and energy efficient windows.

Coatings are applied to the glass of these items to make them electrically conductive whilst also allowing light through. Fluorine doped tin dioxide is one of the materials used in commercial low cost glass coatings as it is able to simultaneously allow light through and conduct electrical charge but it turns out that tin dioxide has as yet untapped potential for improved performance.

Compensating acceptor fluorine interstitials (light green) dramatically reduce electronic performance of tin dioxide transparent conducting glass coatings doped with fluorine atoms (dark green). Credit: University of Liverpool

Compensating acceptor fluorine interstitials (light green) dramatically reduce electronic performance of tin dioxide transparent conducting glass coatings doped with fluorine atoms (dark green). Credit: University of Liverpool

In a paper published in the journal Advanced Functional Materials, physicists identify the factor that has been limiting the conductivity of fluorine doped tin dioxide, which should be highly conductive because fluorine atoms substituted on oxygen lattice sites are each expected to give an additional free electron for conduction.

The scientists report, using a combination of experimental and theoretical data, that for every two fluorine atoms that give an additional free electron, another one occupies a normally unoccupied lattice position in the tin dioxide crystal structure.

Each so-called “interstitial” fluorine atom captures one of the free electrons and thereby becomes negatively charged. This reduces the electron density by half and also results in increased scattering of the remaining free electrons. These combine to limit the conductivity of fluorine doped tin dioxide compared with what would otherwise be possible.

PhD student Jack Swallow, from the University’s Department of Physics and the Stephenson Institute for Renewable Energy, said: “Identifying the factor that has been limiting the conductivity of fluorine doped tin dioxide is an important discovery and could lead to coatings with improved transparency and up to five times higher conductivity, reducing cost and enhancing performance in a myriad of applications from touch screens, LEDs, photovoltaic cells and energy efficient windows.”

The researchers now intend to address the challenge of finding alternative novel dopants that avoid these inherent drawbacks.

Kateeva, a developer of inkjet deposition equipment solutions for OLED display manufacturing, today formally introduced a suite of YIELDjet inkjet equipment for red, green and blue (RGB) pixel deposition to enable the development and pilot production of large-size OLED displays, including televisions (TVs). The new YIELDjet family, which consists of the EXPLORE and EXPLORE PRO systems, provides display manufacturers with an industry-proven inkjet deposition platform to help bring the next generation of OLED TVs and other large-size displays to market. This year so far, Kateeva has shipped four systems from the EXPLORE family. The company expects to ship three additional systems by the second quarter of 2018.

The EXPLORE family broadens Kateeva’s product line and deepens the company’s penetration of the OLED display sector. The YIELDjet FLEX system already leads the inkjet deposition market for OLED mobile displays, with multiple systems deployed in mass production for OLED thin film encapsulation (TFE). The YIELDjet EXPLORE and EXPLORE PRO tools contain the same demonstrated core technologies found in the YIELDjet platform, with system designs that are optimized for rapid development of RGB pixel printing. Both tools, for instance, feature Kateeva’s unique nitrogen printing capability, which provides an oxygen- and- moisture-free enclosure for inkjet deposition. This capability is known to greatly increase OLED device lifetime.

The new products aim to help customers compress their in-house development- to- pilot-production cycle for printed RGB OLED displays, including TVs. To achieve this, the systems are designed for flexibility and scalability. The EXPLORE processes small panels (up to 200 mm square) for initial development, while the EXPLORE PRO targets mid-size panels (up to 55-in. display) for development through pilot production. As many as nine inks can be loaded into each tool at the same time. This enables accelerated evaluation of multiple materials during critical phases of process development.

The products offer an alternative to the traditional RGB pixel deposition approach of vacuum thermal evaporation (VTE) with a fine metal mask (FMM). Instead, printing is used to form the active layers within the pixels that generate the red, green and blue light emitted from the OLED device. Manufacturers are interested in using inkjet printing to overcome the scalability limitations of VTE with FMM.

VTE with FMM is currently used for small displays to fabricate patterned RGB active layers. However, the approach has not been successfully scaled to enable production of large displays such as those required for premium TVs. White OLED (WOLED) TV works around the issue by using VTE to form an un-patterned white OLED layer. This eliminates the need for FMM and creates the red, green, and blue light using three separate color filters (similar to the structure of a liquid crystal display). Although WOLED TVs are considered the best on the market, RGB OLED TVs fabricated using inkjet deposition can potentially offer superior performance. Moreover, manufacturing costs could be 20 percent lower, according to a recent analysis.

The potential of inkjet-fabricated RGB OLED TVs, coupled with the enabling capabilities of the YIELDjet EXPLORE products, have generated excitement among OLED display manufacturers, according to Kateeva’s President and COO, Dr. Conor Madigan. “There is increasing enthusiasm among our customers to develop RGB OLED TVs and we believe our new systems will help them accelerate their initiatives,” he said. “These companies are innovating rapidly and pioneering novel processes to mass-produce differentiated displays. Our products let them utilize Kateeva’s unique technologies as part of their inkjet RGB pixel printing programs. We are excited to work with them to move this approach closer to mass production.”

The YIELDjet Inkjet Advantage

Kateeva’s inkjet solution for RGB pixel deposition R&D utilizes core disruptive features found in the company’s YIELDjet platform. This OLED production equipment solution has already helped display manufacturers transition to flexible OLED mass production with high yields and low costs. Now, the same features, coupled with additional innovations for RGB pixel printing, promise to enable a similar transition to RGB OLED TV mass production by addressing customers’ yield and productivity priorities. Key YIELDjet technical features and advantages include:

  • Pure process environment: Trace amounts of oxygen and moisture, as well as large particles, can degrade OLED device performance and reduce yield. The same impurities are known to degrade OLED device lifetime. Processing in a clean, high-purity environment, therefore, is a central requirement for OLED front-plane manufacturing equipment. The YIELDjet solution features a specially designed nitrogen-purged enclosure that delivers an ultra-pure printing environment and enables fast recovery after maintenance. The result is longer OLED lifetime, higher yields, and higher uptime.
  • Superior uniformity: Non-uniform deposition of the printed layer can create “mura”. Mura, which refers to visibly noticeable non-uniformities in the finished display, will reduce yield. Print non-uniformity can be caused by inherent variations in the nozzles contained in the print array. The YIELDjet platform addresses the issue by combining two proprietary technologies—ultra-fast print head monitoring and Smart Mixing™ software. A remote drop inspection (RDI) system measures the drop characteristics for every nozzle in the print array on a continuous basis so that the state of the print array is known at all times. The nozzle data is used to calibrate the proprietary Smart Mixing software, which determines the optimized nozzle mixing for each sub-pixel during the print. The result is a system that delivers displays that are free of print mura in mass production.
  • High resolution: To achieve the resolution required for a product like an 8K TV, a key printing imperative is ink drop placement accuracy. This requires high stage accuracy. To enable high stage accuracy for all glass sizes, Kateeva pioneered the use of a “floating stage” for inkjet printers. With this capability, the glass floats on a thin cushion of nitrogen, which flows from a specially designed stationary stage. As the glass is scanned at high speed over the nitrogen cushion, proprietary stage-error correction technology is deployed to ensure the high accuracies needed for RGB pixel printing.

In addition to RGB pixel printing, the EXPLORE tools can be configured to process OLED TFE. This allows customers who are interested in both applications to conduct R&D or pilot production with the same EXPLORE or EXPLORE PRO tool.

AKHAN Semiconductor, a technology company specializing in the fabrication and application of lab-grown, electronics-grade diamond, announced today the issuance by the Japan Patent Office of a patent covering a method for the fabrication of diamond semiconductor materials, core to applications in automotive, aerospace, consumer electronics, military, defense, and telecommunications systems, amongst others.

“We are ecstatic to be awarded this key patent in Japan. Its issuance protects our proprietary interests in diamond semiconductor in one of the nations leading the globe in diamond research,” said Adam Khan, Founder & Chief Executive Officer, AKHAN Semiconductor, Inc. “Following this year’s issuances of a Taiwan diamond semiconductor patent, and a major US diamond transparent electronics patent, the Japan patent issuance is a further testament to AKHAN’s leadership in the diamond semiconductor space.”

Japan, which has actively funded millions of dollars into diamond electronics research since 2002, earlier this year announced marked progress in the development of diamond semiconductor device performance. The AKHAN granted and issued patent, JP6195831 (B2), is a foreign counterpart of other issued and pending patents owned by AKHAN Semiconductor, Inc. that are used in the company’s Miraj Diamond Platform products. As a key landmark patent, the claims protect uses far beyond the existing applications, including microprocessor applications. Covering the base materials common to nearly all semiconductor components, the intellectual property can be realized in everything from diodes, transistors, and power inverters, to fully functioning diamond chips such as integrated circuitry.

AKHAN’s flagship Miraj Diamond Glass for mobile display and camera lens is 6x stronger, 10x harder, and runs over 800x cooler than leading glass competitors like Gorilla Glass by coating standard commercial glass such as aluminosilicate, BK7, and Fused Silica with lab-grown nanocrystalline diamond. Diamond-based technology is capable of increasing power density as well as creating faster, lighter, and simpler devices for consumer use. Cheaper and thinner than its silicon counterparts, diamond-based electronics could become the industry standard for energy efficient electronics.

“This patent adds to the list of other key patents in the field of Diamond Semiconductor that are owned by the company, including the ability to fabricate transparent electronics, as well as the ability to form reliable metal contacts to diamond semiconductor systems,” said Carl Shurboff, President and Chief Operating Officer, AKHAN Semiconductor, Inc. “This patent bolsters the supporting evidence of AKHAN’s leadership in manufacturing diamond semiconductor products, and supports ongoing efforts with our major defense, aerospace and space system development partners.”

 

Enabling the A.I. era


November 8, 2017

BY PETE SINGER, Editor-in-Chief

There’s a strongly held belief now that the way in which semiconductors will be designed and manufactured in the future will be largely determined by a variety of rapidly growing applications, including artificial intelligence/deep learning, virtual and augmented reality, 5G, automotive, the IoT and many other uses, such as bioelectronics and drones.

The key question for most semiconductor manufacturers is how can they benefit from these trends? One of the goals of a recent panel assembled by Applied Materials for an investor day in New York was to answer that question.

The panel, focused on “enabling the A.I. era,” was moderated by Sundeep Bajikar (former Sellside Analyst, ASIC Design Engineer). The panelists were: Christos Georgiopoulos (former Intel VP, professor), Matt Johnson (SVP in Automotive at NXP), Jay Kerley (CIO of Applied Materials), Mukesh Khare (VP of IBM Research) and Praful Krishna (CEO of Coseer). The panel discussion included three debates: the first one was “Data: Use or Discard”; the second was “Cloud versus Edge”; and the third was “Logic versus Memory.”

“There’s a consensus view that there will be an explosion of data generation across multiple new categories of devices,” said Bajikar, noting that the most important one is the self-driving car. NXP’s Johnson responded that “when it comes to data generation, automotive is seeing amazing growth.” He noted the megatrends in this space: the autonomy, connectivity, the driver experience, and electrification of the vehicle. “These are changing automotive in huge ways. But if you look underneath that, AI is tied to all of these,” he said.

He said that estimates of data generation by the hour are somewhere from 25 gigabytes per hour on the low end, up to 250 gigabytes or more per hour on the high end. or even more in some estimates.

“It’s going to be, by the second, the largest data generator that we’ve seen ever, and it’s really going to have a huge impact on all of us.”

Intel’s Georgiopoulos agrees that there’s an enormous amount of infrastructure that’s getting built right now. “That infrastructure is consisting of both the ability to generate the data, but also the ability to process the data both on the edge as well as on the cloud,” he said. The good news is that sorting that data may be getting a little easier. “One of the more important things over the last four or five years has been the quality of the data that’s getting generated, which diminishes the need for extreme algorithmic development,” he said. “The better data we get, the more reasonable the AI neural networks can be and the simpler the AI networks can be for us to extract information that we need and turn the data information into dollars.” Check out our website at www.solid-state.com for a full report on the panel.

Veeco Instruments Inc. (Nasdaq: VECO) announced today the completion of a strategic initiative with ALLOS Semiconductors (ALLOS) to demonstrate 200mm GaN-on-Si wafers for Blue/Green micro-LED production. Veeco teamed up with ALLOS to transfer their proprietary epitaxy technology onto the Propel Single-Wafer MOCVD System to enable micro-LED production on existing silicon production lines.

“With the Propel reactor, we have an MOCVD technology that is capable of high yielding GaN Epitaxy that meets all the requirements for processing micro-LED devices in 200 millimeter silicon production lines,” said Burkhard Slischka, CEO of ALLOS Semiconductors. “Within one month we established our technology on Propel and have achieved crack-free, meltback-free wafers with less than 30 micrometers bow, high crystal quality, superior thickness uniformity and wavelength uniformity of less than one nanometer.  Together with Veeco, ALLOS is looking forward to making this technology more widely available to the micro-LED ecosystem.”

Micro-LED display technology consists of <30×30 square micron red, green, blue (RGB) inorganic LEDs that are transferred to the display backplane to form sub-pixels. Direct emission from these high efficiency LEDs offers lower power consumption compared with OLED and LCD while providing superior brightness and contrast for mobile displays, TV and wearables. The manufacturing of micro-LEDs requires high quality, uniform epitaxial wafers to meet the display yield and cost targets.

“In contrast to competing MOCVD platforms, Propel offers leading-edge uniformity and simultaneously achieves excellent film quality as a result of the wide process window afforded by Veeco’s TurboDisc® technology,” said Peo Hansson, Ph.D., Senior Vice President and General Manager of Veeco MOCVD Operations. “Combining Veeco’s leading MOCVD expertise with ALLOS’ GaN-on-Silicon epi-wafer technology enables our customers to develop micro-LEDs cost effectively for new applications in new markets.”