Tag Archives: letter-dd-tech

FlexEnable, a leader in the development and industrialization of flexible electronics, has successfully validated a new class of high performance organic semiconductors in a million pound project funded by Innovate UK. It combined materials developed by Flexink with FlexEnable’s proprietary industrial process for making flexible electronics and culminated in a proof of concept plastic LCD display.

The project, Printable Organic Semiconductors for Highly Enhanced Displays (PORSCHED), is part of the UK government’s bid to inspire technological innovation in the areas of electronics, photonics and electrical systems. FlexEnable collaborated with partners Flexink, Imperial College London, and the University of Cambridge, each bringing expertise in the area of organic semiconductors, from materials to device testing and optimization.

The main objective was to create an organic semiconductor that would ensure excellent film uniformity for large-area, flat panel displays. Proof of the performance of this semiconductor is seen in the plastic LCD display demonstrator fabricated at FlexEnable.

Chuck Milligan, CEO of FlexEnable said: “Cutting edge organic semiconductors combined with our industrially proven process and toolkit for flexible electronics have resulted in a high performance transistor platform – as demonstrated by its ability to drive full color video rate plastic LCD. High volume manufacturing for flexible electronics requires semiconductors not only with sufficient mobility, but also with uniformity over large areas and electrical stability. Organic Semiconductors processed at low temperatures enable the use of ultra low cost plastic substrates — even cheaper than glass — and make conformable, flexible, thin and light weight displays possible — transforming where and how we use electronics in our daily lives.”

FlexEnable has developed a complete set of processes to manufacture flexible organic thin film transistor (OTFT) devices and arrays. This has led to the successful volume production of thin, lightweight, and robust backplanes for flexible displays. FlexEnable’s process is very low temperature (<100°C) which opens up a host of manufacturing and cost benefits.

A maximum processing temperature below 100°C brings manufacturing advantages by allowing for the use of lower cost plastic substrates (e.g. PET), minimizing distortion (to improve yield) and enabling low cost mount and demount. However, implementing such a low temperature process presents significant challenges, for example in low temperature deposition and patterning of materials. These challenges have been addressed by FlexEnable’s low temperature process technology for flexible electronics.

A screen-printable functionalized graphene ink supplied by Goodfellow performs better than normal carbon-based ink, opening the door to innovative applications that require exceptional electrical conductivity, excellent ink coverage, and high print resolution. Such applications are found in light flexible displays, plastic electronics, printed circuit boards, thin film photovoltaics, sensors, electrodes, and OLEDs.

The ink is made with HDPlas (R) functionalized graphene nanoplatelets and is optimized for the viscosity and solid contents required of semi-automatic and manual screen-printing equipment. Substrates that can be printed include but are not limited to polymers, ceramics, and papers.

In addition to the distinguishing characteristics stated above, functionalized graphene ink is:

  • Flexible on appropriate substrates
  • Metal-free, 100% organic (non-tarnishing)
  • Curable at low temperatures
  • Environmentally friendly

The ink is fully customizable and can be modified for specific applications. Scientists and printers running trials with the small quantities available from Goodfellow (100g to 1000g) can, if desired, consult with Goodfellow to further tailor performance in order to meet individual needs.

Atmel Corporation, a microcontroller (MCU) and touch technology solutions provider, today announced the company has expanded its portfolio of automotive-qualified maXTouch (R) touchscreen controllers with the mXT641T family. The new family is optimized for capacitive touchpads and touchscreens from 5 to 10 inches. These mXT641T devices are the industry’s first auto-qualified self- and mutual-capacitance controllers meeting the AEC-Q100 standards for high reliability in harsh environments.

The automotive-qualified maXTouch mXT641T family incorporates Atmel’s Adaptive Sensing technology to enable dynamic touch classification, a feature that automatically and intelligently switches between self- and mutual-capacitance sensing to provide users a seamless transition between a finger touch, hover, or glove touch. It eliminates the need for users to manually enable “glove mode” in the operating system to differentiate between hover and glove modes. Adaptive Sensing is also resistant to water and moisture and ensures superior touch performance even in these harsh conditions.

The new devices support stringent automotive requirements including hover and glove support in moist and cold environments, thick lens for better impact resistance, and single-layer shieldless sensor designs in automotive center consoles, navigation systems, radio interfaces and rear-seat entertainment systems. The single-layer shieldless sensor design eliminates additional screen layers, delivering better light transparency resulting in lower power consumption along with an overall lower system cost for the manufacturer.

“More consumers are demanding high-performance touchscreens in their vehicles with capacitive touch technology,” said Rob Valiton, Senior Vice President and General Manager, Automotive, Memory and Secure Products Business Units. “Atmel is continuing to drive more innovative, next-generation touch technologies to the automotive market and our new family of automotive-qualified maXTouch T controllers is further testament to our leadership in this space. Atmel is the only automotive-qualified touch supplier with over two decades of experience in designing, developing, and manufacturing semiconductor solutions that meet the stringent quality and reliability standards for our automotive customers.”

Radiant Vision Systems, a provider of light and color test and measurement systems, announced the release of the ProMetric (R) I29, an ultra high-resolution imaging colorimeter developed to meet the needs of high-volume display and consumer electronics manufacturers. The newest addition to the ProMetric I-Series, the I29 complements the I2, I8, and I16 models, providing a higher resolution option for inspection applications that call for high resolution while meeting short cycle time requirements.

The high spatial resolution of the I29 makes it capable of detecting very small flaws that can be missed by human inspectors. Mura, particles, scratches, and other defects in flat panel displays can be identified and quantified using Radiant’s TrueTest (TM) Automated Visual Inspection software to provide objective and repeatable pass/fail criteria. “The I29 enables inspection of very fine detail, even in large and very high-resolution displays,” stated Doug Kreysar, Chief Solutions Officer for Radiant Vision Systems. “It is also advantageous in ‘multi-channel’ configurations, where multiple devices are tested in a single cycle. Additionally,” continued Kreysar, “the I29 has been engineered for optimal measurement speed, which means the shortest possible takt times are achieved. This is critical to large volume manufacturers.”

Radiant’s ProMetric I Series colorimeters are built around scientific-grade, cooled interline CCD sensors, ranging in resolution from 2 to 29MP. Specially constructed to replicate human spatial perception of brightness and color, they bring the benefits of automation – speed, flexibility, and repeatability – and the accuracy of human vision to production inspection applications. Each model is available with a variety of interchangeable lenses, enabling optimized measurements over a wide range of working distances and viewing angles. ProMetric I supports high-speed USB and Ethernet communications, providing reliable operation over long distances. Smart Technology (TM) features, including electronic lens control and onboard touchscreen, simplify setup and improve measurement accuracy. ProMetric I can be paired to Radiant Vision Systems’ TrueTest software to provide a complete, turnkey solution for testing displays, keyboards, housings, and other products.

Researchers from Holst Centre (set up by TNO and imec), imec and CMST, imec’s associated lab at Ghent University, have demonstrated the world’s first stretchable and conformable thin-film transistor (TFT) driven LED display laminated into textiles. This paves the way to wearable displays in clothing providing users with feedback.

Wearable devices such as healthcare monitors and activity trackers are now a part of everyday life for many people. Today’s wearables are separate devices that users must remember to wear. The next step forward will be to integrate these devices into our clothing. Doing so will make wearable devices less obtrusive and more comfortable, encouraging people to use them more regularly and, hence, increasing the quality of data collected. A key step towards realizing wearable devices in clothing is creating displays that can be integrated into textiles to allow interaction with the wearer.

“Wearable devices allow people to monitor their fitness and health so they can live full and active lives for longer. But to maximize the benefits wearables can offer, they need to be able to provide feedback on what users are doing as well as measuring it. By combining imec’s patented stretch technology with our expertise in active-matrix backplanes and integrating electronics into fabrics, we’ve taken a giant step towards that possibility,” says Edsger Smits, Senior research scientist at Holst Centre.

The conformable display is very thin and mechanically stretchable. A fine-grain version of the proven meander interconnect technology was developed by the CMST lab at Ghent University and Holst Centre to link standard (rigid) LEDs into a flexible and stretchable display. The LED displays are fabricated on a polyimide substrate and encapsulated in rubber, allowing the displays to be laminated in to textiles that can be washed. Importantly, the technology uses fabrication steps that are known to the manufacturing industry, enabling rapid industrialization.

Following an initial demonstration at the Society for Information Display’s Display Week in San Jose, USA earlier this year, Holst Centre has presented the next generation of the display at the International Meeting on Information Display (IMID) in Daegu, Korea, 18-21 August 2015. Smaller LEDs are now mounted on an amorphous indium-gallium-zinc oxide (a-IGZO) TFT backplane that employs a two-transistor and one capacitor (2T-1C) pixel engine to drive the LEDs. These second-generation displays offer higher pitch and increased, average brightness. The presentation will feature a 32×32 pixel demonstrator with a resolution of 13 pixels per inch (ppi) and average brightness above 200 candelas per square meter (cd/m2). Work is ongoing to further industrialize this technology.

The world’s first stretchable and conformable thin-film transistor (TFT) driven LED display laminated into textiles developed by Holst Centre, imec and CSMT.

The world’s first stretchable and conformable thin-film transistor (TFT) driven LED display laminated into textiles developed by Holst Centre, imec and CSMT.

Electronic materials play a key role in touch panel technologies, such as new flexible touch technologies. Equally application know-how plays a vital part in the success of the new material to be used in device manufacture.

Together with ITRI, Taiwan, Heraeus, demonstrated the integration of Clevios conductive polymer based touch panel with AM OLED technology in a highly flexible device. The device was prepared using Clevios PEDOT conductive polymer material (formulated by EOC, Taiwan) patterned on ITRI’s FlexUp substrate. Solution processable and printable Clevios PEDOT: PSS is used as the transparent electrode in this device. In the project a 7 inch flexible Touch Panel / AM OLED device was produced.

Heraeus has been collaborating with ITRI since 2013.

“In this latest development project with ITRI, we have produced a reliable, flexible, advanced touch panel and integrated it with an AM OLED display, opening up new possibilities in flexible, foldable and wearable technologies” said Dr. Stephan Kirchmeyer, Global Marketing Director for the Display & Semiconductor Business at Heraeus. Dr. Janglin Chen, Vice President and General Director of ITRI’s Display Technology Center added, “The co-operation with Heraeus has shown the options for touch panel makers are broader than just metallic based ITO-alternatives.”

Further projects with the ITRI Group and Heraeus in the application of displays are ongoing. The touch sensor electrodes are based on a Clevios PEDOT. The experts at ITRI subsequently patterned the film using Heraeus invisible etch technology. A key element is flexibility which was tested 10,000 times at a bending radius of 5mm. The touch panel is laminated on the AM OLED display. The final product has 5 interactive functions within the display including touch controllable zoom in/out and rotation functions.

The Clevios PEDOT:PSS range from the Display & Semiconductor Business Unit of Heraeus consists of materials for antistatic through to highly conductive applications. Materials are modified for their application method, usually printing or coating, and for their end application requirements. Typically Clevios coatings can reach 100 -250 Ohm/sq. at a transparency of 90 percent (excluding substrate film). Clevios is increasingly finding applications in touch panels and sensors, as well as OLEDs, organic solar cells and security coatings.

Recently, quantum dots (QDs)–nano-sized semiconductor particles that produce bright, sharp, color light–have moved from the research lab into commercial products like high-end TVs, e-readers, laptops, and even some LED lighting. However, QDs are expensive to make so there’s a push to improve their performance and efficiency, while lowering their fabrication costs.

Researchers from the University of Illinois at Urbana-Champaign have produced some promising results toward that goal, developing a new method to extract more efficient and polarized light from quantum dots (QDs) over a large-scale area. Their method, which combines QD and photonic crystal technology, could lead to brighter and more efficient mobile phone, tablet, and computer displays, as well as enhanced LED lighting.

To demonstrate their new technology, researchers fabricated a novel 1mm device (aka Robot Man) made of yellow photonic-crystal-enhanced QDs. Every region of the device has thousands of quantum dots, each measuring about six nanometers. Credit: Gloria See, University of Illinois at Urbana-Champaign

To demonstrate their new technology, researchers fabricated a novel 1mm device (aka Robot Man) made of yellow photonic-crystal-enhanced QDs. Every region of the device has thousands of quantum dots, each measuring about six nanometers. Credit: Gloria See, University of Illinois at Urbana-Champaign

With funding from the Dow Chemical Company, the research team, led by Electrical & Computer Engineering (ECE) Professor Brian Cunningham, Chemistry Professor Ralph Nuzzo, and Mechanical Science & Engineering Professor Andrew Alleyne, embedded QDs in novel polymer materials that retain strong quantum efficiency. They then used electrohydrodynamic jet (e-jet) printing technology to precisely print the QD-embedded polymers onto photonic crystal structures. This precision eliminates wasted QDs, which are expensive to make.

These photonic crystals limit the direction that the QD-generated light is emitted, meaning they produce polarized light, which is more intense than normal QD light output.

According to Gloria See, an ECE graduate student and lead author of the research reported this week in Applied Physics Letters, their replica molded photonic crystals could someday lead to brighter, less expensive, and more efficient displays. “Since screens consume large amounts of energy in devices like laptops, phones, and tablets, our approach could have a huge impact on energy consumption and battery life,” she noted.

“If you start with polarized light, then you double your optical efficiency,” See explained. “If you put the photonic-crystal-enhanced quantum dot into a device like a phone or computer, then the battery will last much longer because the display would only draw half as much power as conventional displays.”

To demonstrate the technology, See fabricated a novel 1mm device (aka Robot Man) made of yellow photonic-crystal-enhanced QDs. The device is made of thousands of quantum dots, each measuring about six nanometers.

“We made a tiny device, but the process can easily be scaled up to large flexible plastic sheets,” See said. “We make one expensive ‘master’ molding template that must be designed very precisely, but we can use the template to produce thousands of replicas very quickly and cheaply.”

Easily manufactured, low cost, lightweight, flexible dielectric polymers that can operate at high temperatures may be the solution to energy storage and power conversion in electric vehicles and other high temperature applications, according to a team of Penn State engineers.

Researcher holds flexible dielectric material. Pull out shows boron nitride nano sheets. Credit: Qing Wang, Penn State

Researcher holds flexible dielectric material. Pull out shows boron nitride nano sheets. Credit: Qing Wang, Penn State

“Ceramics are usually the choice for energy storage dielectrics for high temperature applications, but they are heavy, weight is a consideration and they are often also brittle,” said Qing Wang, professor of materials science and engineering, Penn State. “Polymers have a low working temperature and so you need to add a cooling system, increasing the volume so system efficiency decreases and so does reliability.”

Dielectrics are materials that do not conduct electricity, but when exposed to an electric field, store electricity. They can release energy very quickly to satisfy engine start-ups or to convert the direct current in batteries to the alternating current needed to drive motors.

Applications like hybrid and electric vehicles, aerospace power electronics and underground gas and oil exploration equipment require materials to withstand high temperatures. The researchers developed a cross-linked polymer nanocomposite containing boron nitride nanosheets. This material has high-voltage capacity for energy storage at elevated temperatures and can also be photo patterned and is flexible. The researchers report their results in a recent issue of Nature.

This boron nitride polymer composite can withstand temperatures of more than 480 degrees Fahrenheit under the application of high voltages. The material is easily manufactured by mixing the polymer and the nanosheets and then curing the polymer either with heat or light to create crosslinks. Because the nanosheets are tiny — about 2 nanometers in thickness and 400 nanometers in lateral size, the material remains flexible, but the combination provides unique dielectric properties, which include higher voltage capability, heat resistance and bendability.

“Our next step is to try to make this material in large scale and put it into a real application,” said Wang. “Theoretically, there is no exact scalability limit.”

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

SEMICON West 2015 had a strong and rich undercurrent – the roadmap forward is most certainly 3DIC. Yes, the industry can and we will keep pushing dimensions down, but for most designs the path forward would be “More than Moore.” As Globalfoundries’ CEO Jha recently voiced: It’s clear that More-than-Moore is now mainstream rather than niche. Really it is leading-edge pure digital that is the niche. Instead the high-cost leading edge processes are really niche processes optimized for applications in data centers or for high computational loads, albeit niches with volumes of hundreds of millions of units per year.”

CEA Leti’s CEO in her opening presentation for the SEMICON West–Leti day presented the following slide:

3DIC CEA-Leti

Calling the 28nm as the ‘switch node’ from the homogeneous march of the industry with dimensional scaling to the bifurcation we now see, where “More than Moore” approaches such as SOI and 3DIC are taking on an important portion of future progress.

CEA Leti went even further by dedicating its SEMICON West day entirely to 3D technologies, as is seen in their invitation:

leti day logo

GOING VERTICAL WITH LETI: Solutions to new applications using 3D technologies

  • Welcome– Leti’s 3D integration for tomorrow’s devices > N Semeria
  • CoolCubeTM: 3D sequential integration to maintain Moore’s Law > Faynot
  • Photonics: why 3D integration is mandatory > Metras
  • Computing: 3D technology for better performance > Cheramy
  • Lighting: 3D integration for cost effectiveness > C Robin
  • Nanocharacterization for 3D>  Bleuet
  • Conclusion– Silicon Impulse > N Semeria

Olivier Faynot, Microelectronic Section Manager at LETI, presented the following slide in his CoolCube presentation.

3DIC Cea-Leti coolcub

This illustrates that monolithic 3DIC of 4 tiers could provide the equivalent scaling value of the 5nm node at a far less infrastructure or NRE cost. As the slide states: “New scaling path, compared to 2D.” The time is now for monolithic 3D approaches to take hold a grow.

A similar message is projected by a slide presented by An Steegen of IMEC at their pre-SEMICON Technology Forum:

3DIC device stacking

The same assessment was also presented by Intel’s Jeff Groff from his synopsis of Intel’s Q2 call: “In summary, it seems that Intel is executing fairly well on the process technology side of the business considering the ever increasing difficulty of pushing forward with Moore’s Law. We can expect exciting new structures and materials (just maybe not at 10nm) and an increasing importance of 3-D structures in both logic and memory fabrication.” This resonates with our blog Intel Calls for 3D IC, and was recently voiced by Intel process guru Mark Bohr: “Bohr predicted that Moore’s Law will not come to an abrupt halt, but will morph and evolve and go in a different direction, such as scaling density by the 3D stacking of components rather than continuing to reduce transistor size.” Bohr’s ISSCC slide from earlier this year reasserts this:

3DIC ISSCC

The key two concerns regarding 3DIC stacking using TSV are (a) Cost, noted in the slide above “Poor for Low Cost,” and (b) Vertical connectivity, as voiced by Mark Bohr: “Intel’s Bohr agrees that 3D structures will become more important. He said the kind of through-silicon vias used for today’s chip stacks need to improve in their density by orders of magnitude.”

These limitations are the driver behind the efforts to develop monolithic 3D technology. Monolithic 3D would provide a very cost effective alternative to dimensional scaling with 10,000x higher than TSV vertical connectivity, as illustrated by the following slide of CEA Leti.

3DIC coolcube 2

A 1,000x improvement in energy efficiency using monolithic 3D was calculated by Stanford Prof. Subhasish Mitra. His sum-up at a SEMICON West keynote panel: “We have an opportunity for a thousand-fold increase in energy efficiency…from collaboration between dense computing and memory elements and dense 3-D integration of them.”

Until recently, all monolithic 3D process flows required a significantly new transistor formation flow. Since the transistor process is where the majority of the R&D budget and talent is being allocated, and carries with it fresh reliability concerns, the industry has been most hesitant with respect to monolithic 3D adoption. Yet in this recent industry gathering there is a sense that industry wide interest is strengthening for 3D technologies. The success of 3D NAND as the first monolithic 3D industry wide adoption could help this new interest build even faster.

A recent technology breakthrough, first presented in IEEE S3S 2014 conference (Precision Bonders – A Game Changer for Monolithic 3D) introduced a game changer in the ease of monolithic 3D adoption. Enhancement of this breakthrough will be presented in this year’s IEEE S3S 2015. This new monolithic 3D flow allows the use of the existing fab transistor process for the fabrication of monolithic 3D devices, offering a most attractive path for the industry future scaling technology.

P.S.

A good conference to learn more about these new scaling technologies is the IEEE S3S ‘15, in Sonoma, CA, on October 5th thru 8th, 2015. CEA Leti is scheduled to give an update on their CoolCube program, Qualcomm will present some of their work on monolithic 3D – 3DV, and three leading researchers from Berkeley, Stanford and Taiwan’s NLA Lab will present their work on advanced monolithic 3D integration technologies, and many other authors will be talking about their work on monolithic 3DIC and its ecosystem.

More blog posts from Zvi Or-Bach: 

Moore’s Law to keep on 28nm

Paradigm shift in semi equipment – Confirmed

Moore’s Law has stopped at 28nm

Paradigm shift: Semi equipment tells the future

Using a single molecule as a sensor, scientists in Jülich have successfully imaged electric potential fields with unrivalled precision. The ultrahigh-resolution images provide information on the distribution of charges in the electron shells of single molecules and even atoms. The 3D technique is also contact-free. The first results achieved using “scanning quantum dot microscopy” have been published in the current issue of Physical Review Letters. The technique is relevant for diverse scientific fields including investigations into biomolecules and semiconductor materials.

“Our method is the first to image electric fields near the surface of a sample quantitatively with atomic precision on the sub-nanometre scale,” says Dr. Ruslan Temirov from Forschungszentrum Jülich. Such electric fields surround all nanostructures like an aura. Their properties provide information, for instance, on the distribution of charges in atoms or molecules.

For their measurements, the Jülich researchers used an atomic force microscope. This functions a bit like a record player: a tip moves across the sample and pieces together a complete image of the surface. To image electric fields up until now, scientists have used the entire front part of the scanning tip as a Kelvin probe. But the large size difference between the tip and the sample causes resolution difficulties – if we were to imagine that a single atom was the same size as a head of a pin, then the tip of the microscope would be as large as the Empire State Building.

Single molecule as a sensor

In order to improve resolution and sensitivity, the scientists in Jülich attached a single molecule as a quantum dot to the tip of the microscope. Quantum dots are tiny structures, measuring no more than a few nanometres across, which due to quantum confinement can only assume certain, discrete states comparable to the energy level of a single atom.

The molecule at the tip of the microscope functions like a beam balance, which tilts to one side or the other. A shift in one direction or the other corresponds to the presence or absence of an additional electron, which either jumps from the tip to the molecule or does not. The “molecular” balance does not compare weights but rather two electric fields that act on the mobile electron of the molecular sensor: the first is the field of a nanostructure being measured, and the second is a field surrounding the tip of the microscope, which carries a voltage.

“The voltage at the tip is varied until equilibrium is achieved. If we know what voltage has been applied, we can determine the field of the sample at the position of the molecule,” explains Dr. Christian Wagner, a member of Temirov’s Young Investigators group at Jülich’s Peter Grünberg Institute (PGI-3). “Because the whole molecular balance is so small, comprising only 38 atoms, we can create a very sharp image of the electric field of the sample. It’s a bit like a camera with very small pixels.”

Universally applicable

A patent is pending for the method, which is particularly suitable for measuring rough surfaces, for example those of semiconductor structures for electronic devices or folded biomolecules. “In contrast to many other forms of scanning probe microscopy, scanning quantum dot microscopy can even work at a distance of several nanometres. In the nanoworld, this is quite a considerable distance,” says Christian Wagner. Until now, the technique developed in Jülich has only been applied in high vacuum and at low temperatures: essential prerequisites to carefully attach the single molecule to the tip of the microscope.

“In principle, variations that would work at room temperature are conceivable,” believes the physicist. Other forms of quantum dots could be used as a sensor in place of the molecule, such as those that can be realized with semiconductor materials: one example would be quantum dots made of nanocrystals like those already being used in fundamental research.