Silicon Industry News

Latest news from the semiconductor industry

Researchers use emerging memory devices to develop electronic circuits for cybersecurity applications

From Tech Xplore:

While we embrace the way the Internet of Things already is making our lives more streamlined and convenient, the cybersecurity risk posed by millions of wirelessly connected gadgets, devices and appliances remains a huge concern. Even single, targeted attacks can result in major damage; when cybercriminals control and manipulate several nodes in a network, the potential for destruction increases.

UC Santa Barbara computer science professor Dmitri Strukov is working to address the latter. He and his team are looking to put an extra layer of security on the growing number of internet- and Bluetooth-enabled devices with technology that aims to prevent cloning, the practice by which nodes in a network are replicated and then used to launch attacks from within the network. A chip that deploys ionic memristor technology, it is an analog memory hardware solution to a digital problem.

“You can think of it as a black box,” said Strukov, whose new paper, “Hardware-intrinsic security primitives enabled by analogue state and nonlinear conductance variations in integrated memristors,” appears on the cover of Nature Electronics. Due to its nature, the chip is physically unclonable and can thus render the device invulnerable to hijacking, counterfeiting or replication by cyber criminals.

Key to […]

April 26th, 2018|General News Feed|

Platform for fully vertical gallium nitride on silicon power devices

From Semicoductor Today:

Massachusetts Institute of Technology (MIT) in the USA and Enkris Semiconductor Inc in China claim record performance for vertical gallium nitride (GaN) power diodes on foreign substrate [Yuhao Zhang et al, IEEE Electron Device Letters, published online 26 March 2018]. The researchers have developed a new platform for vertical GaN on silicon (Si) that creates a back-side trench, allowing a back contact to be made to the n-GaN layers.

The trench etching removes resistive buffer layers that have up to now mainly restricted GaN/Si power electronics to lateral or quasi-vertical structures with all contacts on the top side of epitaxial structures. The buffer layers are needed to bridge the lattice and thermal expansion mismatch between the foreign substrate and the GaN crystal structure. Fully vertical GaN power devices have generally been demonstrated on very expensive bulk or free-standing GaN substrates.

Vertical power devices are attractive because they push peak electric fields away from the surfaces and associated electron states that can cause premature breakdown. Vertical structures hence allow higher currents and voltages in more compact footprints. Also, lateral/quasi-vertical devices suffer from current crowding, which increases Joule heating.

The advantages of using silicon substrates are large diameter (8-inch) and low cost […]

April 26th, 2018|General News Feed|

Statistical designs accelerate the optimization of layered 2-D crystals

From phys.org:

It has been estimated that there are more than 10100 possible materials that can be synthesised, grown and optimised. Materials design can be a slow and laborious process, and investigating the full parameter space is a formidable challenge. Machine learning and other advanced statistical techniques will almost certainly accelerate materials development, but many materials scientists are unaware that very basic statistical design methods can accelerate the process. These include the fractional factorial design of experiments, which is more commonly used by product engineers than materials scientists.

Layered chalcogenide materials, such as Sb2Te3, have attracted substantial attention in the last decade because of their topologically non-trivial bad structure, and use in thermoelectrics and interfacial phase change memory. High quality crystals of Sb2Te3 are required for high-performance memory and energy converting devices. However, efficiently optimising the crystal quality is challenging because it is highly sensitive to a large number of synthesis parameters, such as temperature, pressure, surrounding materials and deposition rate. It is often difficult to determine the parameters that significantly affect the crystal quality, i.e., “we are unable to see the wood in the trees,” and therefore, it is difficult to know which design parameter should be prioritised during optimisation.

Researchers from the Singapore University […]

April 26th, 2018|General News Feed|

Next EUV Issue: Mask 3D Effects

From Semiconductor Engineering:

As extreme ultraviolet (EUV) lithography moves closer to production, the industry is paying more attention to a problematic phenomenon called mask 3D effects.

Mask 3D effects involve the photomask for EUV. In simple terms, a chipmaker designs an IC, which is translated from a file format into a photomask. The mask is a master template for a given IC design. It is placed in a lithography scanner, which projects light through the mask. That, in turn, is used to pattern images on a wafer.

For EUV, the mask is a multi-layer structure with absorbers. Based on tantalum (Ta) materials, each absorber consists of a 3D-like feature that juts out on top of the mask. In operation, EUV light hits the mask at a 6-degree angle, with the reflections potentially causing a shadowing effect or photomask-induced imaging aberrations on the wafer. This issue, known as mask 3D effects, can result in unwanted feature-size dependent focus and pattern placement shifts. In addition, there can be large differences in focus between 1D and 2D features, which limits the yield process windows, according to experts.

The industry has known about the problem for years, but it hasn’t been a top priority. For one thing, […]

April 25th, 2018|General News Feed|

Silicon as a new storage material for the batteries of the future

From phys.org:

Longer life times, larger ranges and faster recharging—developments such as electric mobility or the miniaturisation of electronics require new storage materials for batteries. With its enormous storage capacity, silicon would potentially have decisive advantages over the materials used in commercial available lithium-ion batteries. But due to its mechanical instability, it has so far been almost impossible to use silicon for storage technology. A research team from the Institute for Materials Science at Kiel University, in cooperation with the company RENA Technologies GmbH, is developing anodes made of 100% silicon, as well as a concept for their industrial production. Through targeted structuring of its surface at the micrometer level, the team can fully exploit the storage potential of silicon. This opens up a completely new approach to rechargeable batteries, as well as the energy storage of tomorrow. This week, the partners are presenting the production and potential use of silicon anodes at the Hannover Messe (23 – 27 April), at the CAU booth (Hall 2, C07).

Silicon has long been a potential candidate for the e-lectric mobility, according to materials scientist Dr. Sandra Hansen. “Theoretically, silicon is the best material for anodes in batteries. It can store up to 10 times more […]

April 25th, 2018|General News Feed|

Here’s a feasible way for our devices to send data with light

From Futurity:

Researchers have developed a method to fabricate silicon chips that can communicate with light and are no more expensive than current chip technology.

The new microchip technology capable of optically transferring data could solve a severe bottleneck in current devices by speeding data transfer and reducing energy consumption by orders of magnitude.
“Instead of a single wire carrying around 10 gigabits per second, you can have a single optical fiber carrying 10 to 20 terabits per second…”
The electrical signaling bottleneck between current microelectronic chips has left light communication as one of the only options left for further technological progress. The traditional method of data transfer—electrical wires—has a limit on how fast and how far it can transfer data. It also uses a lot of power and generates heat. With the relentless demand for higher performance and lower power in electronics, these limits have been reached. But with this new development, that bottleneck is solvable.

“Instead of a single wire carrying around 10 gigabits per second, you can have a single optical fiber carrying 10 to 20 terabits per second—so a thousand times more in the same footprint,” says Milos Popovic, assistant professor of electrical and computer engineering at Boston University, one […]

April 25th, 2018|General News Feed|

US group separates on-chip optics and electronics

From optics.org:

A team of researchers led by groups at MIT, the University of California at Berkeley, and Boston University have announced what they are calling “another milestone” in electro-optical chip development.

This is a new technique for assembling on-chip optics and electronic separately, which enables the use of more modern transistor technologies. New it may be, but the technique requires only existing manufacturing processes.

The latest breakthrough, reported in Nature, follows the group’s 2015 fabrication of a previous generation microprocessor, constructed using only existing manufacturing processes, which integrated electronic and optical components on the same chip.

At that time, the researchers’ approach required that the chip’s electrical components be built from the same layer of silicon as its optical components. That meant relying on an established chip technology in which the silicon layers for the electronics were thick enough for optics.

‘Optimization’

“The most promising thing about this work is that you can optimize your photonics independently from your electronics,” commented Amir Atabaki, a research scientist at MIT’s Research Laboratory of Electronics and one of three first authors on the new paper.

“We now have different silicon electronic technologies, and if we can just add photonics to them, it would be a great capability for future […]

April 24th, 2018|General News Feed|

8-inch wafer capacity to remain tight by 2020 on explosive IoT demand

From DigiTimes:
As IoT (Internet of Things) chips currently rely largely on 8-inch wafer fabs for fabrication, the increasing demand for such chips will keep such fabs in Taiwan and China running at full capacity through the end of 2018, with the capacity supply likely to fall short of demand by 2020 at least due to limited capacity expansions worldwide, according to industry sources.
The sources said that global tech giants and telecom operators are joining IoT application markets, and governments in many countries are injecting substantial resources into IoT infrastructure construction, showing explosive demand for IoT-related chipset solutions. This has enabled 8-inch wafer fabs operated by Taiwan Semiconductor Manufacturing Company (TSMC), Vanguard International Semiconductor (VIS), United Microelectronics (UMC), as well as China’s Semiconductor Manufacturing International Corp (SMIC) and Hua Hong Semiconductor to post sharp revenue and earnings growths.
UMC likely to see major turnaround
Sources from Taiwan’s IC design sector said that compared with TSMC, VIS and China foundry houses, UMC is in a better position to stand out in 8-inch wafer foundry business as it has fully depreciated the related equipment and can readily make profits for many years after landing orders. They indicated that UMC has a chance to see […]

April 24th, 2018|General News Feed|

Gallium oxide shows high electron mobility, making it promising for better and cheaper devices

From phys.org:

The next generation of energy-efficient power electronics, high-frequency communication systems, and solid-state lighting rely on materials known as wide bandgap semiconductors. Circuits based on these materials can operate at much higher power densities and with lower power losses than silicon-based circuits. These materials have enabled a revolution in LED lighting, which led to the 2014 Nobel Prize in physics.

In new experiments reported in Applied Physics Letters, researchers have shown that a wide-bandgap semiconductor called gallium oxide (Ga2O3) can be engineered into nanometer-scale structures that allow electrons to move much faster within the crystal structure. With electrons that move with such ease, Ga2O3 could be a promising material for applications such as high-frequency communication systems and energy-efficient power electronics.

“Gallium oxide has the potential to enable transistors that would surpass current technology,” said Siddharth Rajan of Ohio State University, who led the research.

Because Ga2O3 has one of the largest bandgaps (the energy needed to excite an electron so that it’s conductive) of the wide bandgap materials being developed as alternatives to silicon, it’s especially useful for high-power and high-frequency devices. It’s also unique among wide bandgap semiconductors in that it can be produced directly from its molten form, which enables large-scale manufacturing of high-quality crystals.

For use in electronic devices, the […]

April 24th, 2018|General News Feed|

Silicon on Insulator Market Driven by the Rising Demand for Scaling of CMOS ICs

From Digital Journal:
Continuous efforts are being made by companies in the semiconductor and electronics industry to mainstream SOI technology by bringing improvements in their chip fabrication process. Fully depleted silicon on insulator (FD-SOI) has proven to be a simplified process technology that helps in the marked miniaturization of transistors and dramatically improves the performance of SOI devices.
This press release was orginally distributed by SBWire

San Francisco, CA — (SBWIRE) — 04/18/2018 — Silicon on insulator (SOI) is a chip manufacturing technology that uses layered silicon–insulator–silicon substrates instead of the conventional bulk silicon and is used in making advanced semiconductor devices. The continued demand for miniaturization of electronic devices and advances in microprocessor design are seminal developments leading to the evolution of the silicon on insulator market. SOI wafers and transistors find wide applications in microelectronics to make advanced complementary metal-oxide-semiconductor (CMOS) integrated circuit (IC) fabrication.

SOI-based devices are extensively used in a number of micro-electro-mechanical systems (MEMS) since they can lower stray device capacitance, thereby significantly improving device performance. Over the forecast period, the silicon on insulator market is expected to witness a bright prospect in the next-generation microprocessor design and wafer engineering technology.

Global Silicon on Insulator Market: Key Trends

The silicon on […]

April 23rd, 2018|General News Feed|

The Annual Lithography Issue

From Electronic Engineering Journal:

It’s that time of year again. The SPIE Advanced Lithography conference has come and gone, and the time has come for our annual update on EUV technology, along with directed self-assembly (DSA). Gone are the days of big news for either of those categories. Which means there’s lots of little news of the update variety.

Let’s start with basic stats for EUV. They represent a litany of the things that need improvement as we move towards full production in high volume. Much of this comes from a conversation I had with ASML. If you’re new to this scene, they are the only game in town for the scanners that take all of the diverse bits of challenging EUV technology and bring them together in a giant box that will sit on the production floor. (One of which I got to see in person at Imec last year… through glass, of course… They wouldn’t let me drive it…)

Energy and Throughput

Top of the list are source energy and the closely related throughput goals. The lower the energy, the longer each exposure has to be to get the right number of photons delivered, and long exposures mean you can’t get […]

April 23rd, 2018|General News Feed|

Organic solar cells reach record efficiency, benchmark for commercialization

From Tech Xplore:

In an advance that makes a more flexible, inexpensive type of solar cell commercially viable, University of Michigan researchers have demonstrated organic solar cells that can achieve 15 percent efficiency.

This level of efficiency is in the range of many solar panels, or photovoltaics, currently on the market.

“Organic photovoltaics can potentially cut way down on the total solar energy system cost, making solar a truly ubiquitous clean energy source,” said Stephen Forrest, the Peter A. Franken Distinguished University Professor of Engineering and Paul G. Goebel Professor of Engineering, who led the work.

At 15 percent efficiency and given a 20-year lifetime, researchers estimate organic solar cells could produce electricity at a cost of less than 7 cents per kilowatt-hour. In comparison, the average cost of electricity in the U.S. was 10.5 cents per kilowatt-hour in 2017, according to the U.S. Energy Information Administration.

Organic solar cells incorporate carbon into their construction to offer several advantages over conventional “inorganic” cells. Silicon-based inorganic solar panels are costly to make—composed of thick, rigid sheets that require fixed installation points.

But carbon-based organic solar cells could be inexpensively manufactured in rolls that are thin enough to bend and curve around structures or within clothing, and made any color, even […]

April 23rd, 2018|General News Feed|

Integrating optical components into existing chip designs

From phys.org:

Two and a half years ago, a team of researchers led by groups at MIT, the University of California at Berkeley, and Boston University announced a milestone: the fabrication of a working microprocessor, built using only existing manufacturing processes, that integrated electronic and optical components on the same chip.

The researchers’ approach, however, required that the chip’s electrical components be built from the same layer of silicon as its optical components. That meant relying on an older chip technology in which the silicon layers for the electronics were thick enough for optics.

In the latest issue of Nature, a team of 18 researchers, led by the same MIT, Berkeley, and BU groups, reports another breakthrough: a technique for assembling on-chip optics and electronic separately, which enables the use of more modern transistor technologies. Again, the technique requires only existing manufacturing processes.

“The most promising thing about this work is that you can optimize your photonics independently from your electronics,” says Amir Atabaki, a research scientist at MIT’s Research Laboratory of Electronics and one of three first authors on the new paper. “We have different silicon electronic technologies, and if we can just add photonics to them, it’d be a great capability for future communications and computing […]

April 20th, 2018|General News Feed|

Processing power beyond Moore’s Law

From phys.org:

In 1965, businessman and computer scientist Gordon Moore observed that the number of transistors in a dense integrated circuit doubles approximately every two years, which means a doubling of computer processing power. The prediction was so accurate that this phenomenon was dubbed “Moore’s Law.”

To keep Moore’s Law going, manufacturers need to continue shrinking transistors. Funded by the EU Future and Emerging Technology (FET) programme, the TOLOP project sought to innovate computer processing in this way by using electronic devices with a single electron, allowing the number of components present in a processor to be reduced.

The challenge was to study how single-electron transistors could be mass produced, integrated in conventional circuits and see if they could work reliably. TOLOP worked on single-electron and single-atom transistors, which designs are not that different from those used in today’s microprocessors.

“The big advance that TOLOP has demonstrated is that single-electron devices can be built at an industrial level,” says M. Fernando Gonzalez-Zalba, at the Hitachi Cambridge Laboratory, University of Cambridge, UK.

The research demonstrated that the new single-electron devices can be mass produced and perform additional functionalities than current state-of-the-art transistors. The downside is that it can only be done below room temperature because […]

April 20th, 2018|General News Feed|

Flexible Technology is One Step Closer with this New Oxide-based Transistor

From Electronics360:

Flexible TVs, wearable technology and flexible phones are closer than you think. Once upon a time, these technologies were the dreams of science-fiction writers. But wearables are being developed constantly and flexible screens are definitely in our near future. Researchers from the University of Manchester and Shandong University in China created a new nanoscale transistor that is the key to truly wearable technology and flexible electronics.

The new nanoscale transistor is called a thin film transistor (TFT) and is made out of an oxide semiconductor. The TFT is the first oxide semiconductor-based transistor that can operate at 1 GHz. This speed could make the next generation of electronic gadgets faster, brighter and more flexible.

The TFT is typically used in LCD screens that are in smartphones, tablets and high-definition TVs today. The LCD has a TFT behind all the pixels. The TFT act like individual switches so the pixels can change rapidly.

The current TFTs are silicon based. This means they are opaque, rigid and expensive when compared to the oxide semiconductors that are coming from the U.K. and China teams. Oxide TFTs will provide users with an improved picture on LCD screens and the flexibility is what is really impressing […]

April 19th, 2018|General News Feed|

Rising component and material costs to put pressure on gross margin

From DigiTimes:
IC foundries, and PC and handset manufacturers continue to encounter rising costs of components and materials, and will see their gross margins come under downward pressure in 2018, according to industry sources.
Prices for silicon wafers, passive components, DRAM, and other chip components and materials have been rising on tight supply, the sources indicated. Contract IC and device manufacturers are under increasing cost pressure, the sources said.
In the silicon wafer market, for example, supply continues to lag demand. Chip demand for automotive electronics, IoT, AI and cryptocurrency mining applications has been robust, while major silicon wafer producers remain reluctant to expand substantially production capacity.
GlobalWafers said recently the company has already seen clear order visibility through 2020. GlobalWafers is among the world’s top-5 semiconductor silicon wafer providers, along with Japan’s Shin-Etsu and Sumco, Germany-based Siltronic and South Korea’s SK Siltron.
Semiconductor wafer prices will continue rising in 2018 and 2019, with prices for 6-, 8- and 12-inch wafers all looking bullish, GlobalWafers chairwoman Doris Hsu was quoted as saying in previous reports.
Taiwan Semiconductor Manufacturing Company (TSMC) disclosed previously a rally in silicon wafer prices already undermined its gross margin by 0.2pp in 2017. The foundry expects silicon wafer prices to continue […]

April 19th, 2018|General News Feed|

Plastic as a heat conductor

From The Chemical Engineer:

A PLASTIC has been developed that can dissipate heat instead of trapping it, which could be used to stop electronic devices overheating.

Plastics are excellent insulators but trapping heat can be a problem for devices such as laptops and mobiles. Creating plastics that can transport heat has so far been a challenge. Polymers trap heat because they are made of long chains of disordered monomers which also have weak molecular interactions. Previous work on creating heat-conducting polymers used either intramolecular forces, which enable heat transport along chains, or intermolecular forces, which enable transport between chains. These conventional approaches have scalability challenges or are limited to heat transport in one direction.

A team of engineers at MIT and Argonne National Laboratory has devised a method that uses both intramolecular and intermolecular forces to create a polymer that can transport heat in all directions.

“Traditional polymers are both electrically and thermally insulating,” said Yanfei Xu, from MIT’s department of mechanical engineering. “Our polymer can thermally conduct and remove heat much more efficiently. We believe polymers could be made into next-generation heat conductors for advanced thermal management applications, such as a self-cooling alternative to existing electronics casings.”

They used oxidative chemical vapour deposition […]

April 19th, 2018|General News Feed|

Semiconductor silver sulfide stretches like metal

From Chemical & Electrical Engineering News:

To build electronic devices that can bend, fold, or stretch, engineers need flexible electronic materials. Engineers can choose from a wide range of ductile metals and insulators that deform under a force without rupturing. But they have far fewer options when it comes to semiconductors. Brittle inorganic semiconductors tend to crack under strain, while ductile organic semiconductors offer relatively poor electronic performance.

Researchers in China and Germany have now found that a form of silver sulfide (α-Ag2S) not only boasts promising electronic properties, but also is the first known inorganic semiconductor that is ductile at room temperature (Nat. Mater. 2018, DOI: 10.1038/s41563-018-0047-z). The team used density functional theory calculations to understand the atomic origins of the material’s ductility, providing a possible general approach to discover other flexible semiconductors for applications such as biosensors or optoelectronics.

The discovery came by accident when a team member tried to prepare a sample of α-Ag2S for X-ray powder diffraction, as part of an ongoing project to develop thermoelectric materials that convert heat into electrical energy. Rather than forming a powder when pounded in a mortar, the material simply deformed like a metal. “This was quite unexpected,” says Yuri Grin at the Max Planck Institute […]

April 18th, 2018|General News Feed|

New Model Accurately Predicts the Effects of Mechanical Stress on Corrosion

From AZO Materials:

Annually, the impacts of corroding materials cost the global economy over $1 trillion. Some alloys are exposed to extreme temperatures and stress, causing the formation of an oxide film, which in turn accelerates the breakdown of the alloys.

The exact reasons that make these high-stress and high-temperature conditions so favorable for corrosion are unclear, particularly in microelectromechanical devices. Chinese researchers have begun to work toward understanding the causes for corrosion of materials under mechanical stress. They have reported their study in the Journal of Applied Physics, from AIP Publishing.

A research group led by Professor Xue Feng of Tsinghua University has explained the effect of mechanical stress on the oxidation process. Their model makes use of oxidation kinetics to describe how stress alters chemical reactions at interfaces and cause oxidation, and how stress affects the oxidation species that diffuse all over the oxide layer.

“Our work is in the direction of fundamental research, but it is indeed based on engineering problems,” Feng noted. “We expect that it provides guidelines for more accurate predictions in engineering applications, including better designs to compensate for material and system failure by taking into account the oxidation process.”

 

For several years, the focus of the study of the […]

April 18th, 2018|General News Feed|

More Lithography/Mask Challenges

SE: Besides today’s extreme ultraviolet (EUV) lithography, the industry is also developing next-generation EUV. This is known as high numerical aperture EUV or high NA EUV. Why do we need high NA EUV?

McIntyre: It’s pretty much for all the same reasons that we want to go to EUV, compared to immersion. With immersion today, you are talking about three, four or five exposures or more. That gets very expensive and complicated. There is a lot of processing required. Going to EUV, you go back to a single exposure solution. That simplifies the process quite dramatically, reduces the cycle times and overall costs. At some point, in the next node or two or three, we will start using multi-patterning. We need to use EUV with multi-patterning. At the same point, you have the same exact argument. Then, high NA starts to become attractive. Going to a tool that has a higher resolution ends up allowing you to reduce the mask count and reduce the process complexity.

SE: What are the challenges with high NA EUV?

McIntyre: You still have stochastics effects to worry about. Your feature sizes get smaller, so the impact actually goes up for a constant dose value. With the […]

April 17th, 2018|General News Feed|

Combining boron nitride and gallium oxide to boost power transistor

From Semiconductor Today:

Korea University and Korea Electrotechnology Research Institute (KERI) have used hexagonal boron nitride (h-BN) as part of a field-plate structure for β-structure gallium oxide (β-Ga2O3) metal-semiconductor field-effect transistors (MESFETs) [Jinho Bae et al, Appl. Phys. Lett., vol112, p122102, 2018]. The off-state breakdown reached 344V.

Devices based on β-Ga2O3 are being developed in the hope of power electronics applications, based on an ultra-wide 4.85eV direct bandgap and good thermal stability. Theory also suggests that the material has potential for high saturation velocity (~2x107cm/s) and breakdown field (8MV/cm). The Baliga and Johnson figures of merit for β-Ga2O3 are 3214.1 and 2844.4, respectively, which correspondingly compare with gallium nitride’s 846.0 and 1089.0 and with silicon carbide’s 317.1 and 277.8. These figures focus on the suitability of the material for high-frequency power electronics. Another development is larger-diameter commercial β-Ga2O3 substrates beyond the 2 inches of gallium nitride.

The researchers used single-crystal β-Ga2O3 substrate from Tamura Corp for the transistor (Figure 1). The material was mechanically exfoliated into quasi-two-dimensional flakes 200-400nm thick using adhesive tape. The flakes were transferred onto a 300nm silicon dioxide layer on a 500μm-thick silicon substrate. Ohmic source-drain electrodes consisted of annealed titanium/gold. The ~70nm-thick h-BN field-plate insulation material was mechanically exfoliated from bulk […]

April 17th, 2018|General News Feed|

From insulator to conductor in a flash

From phys.org:

In recent decades, computers have become faster and hard disks and storage chips have reached enormous capacities. But this trend cannot continue forever. Physical limits are preventing silicon-based computer technology from attaining additional speed gains. Researchers are optimistic that the next era of technological advancements will start with the development of novel information-processing materials and technologies that combine electrical circuits with optical ones. Using short laser pulses, a research team led by Misha Ivanov of the Max Born Institute in Berlin, together with scientists from the Russian Quantum Center in Moscow, has shed light on the extremely rapid processes taking place within these novel materials. Their results appear in Nature Photonics.

Of particular interest for modern material research in solid state physics are strongly correlated systems, which exhibit strong interactions between electrons. Magnets are a good example: The electrons in magnets align themselves in a preferred direction of spin inside the material, producing the magnetic field. But there are other, entirely different structural orders that deserve attention. For example, in so-called Mott insulators, the electrons ought to flow freely and the materials should therefore be able to conduct electricity as well as metals. But the mutual interaction between electrons in these […]

April 17th, 2018|General News Feed|

Sharpening the X-ray view of the nanocosm

From phys.org:

A novel lens offers scientists the sharpest X-ray images yet from the nano world. The device is made from alternating layers of tungsten carbide and silicon carbide and can focus hard X-rays into a spot of less than ten nanometers in diameter. The study, led by Saša Bajt from the German research center Deutsches Elektronen-Synchrotron DESY, is reported in Light: Science and Applications.

The short wavelength and the penetrating nature of X-rays are ideal for the microscopic investigation of complex materials. For example, nanometer resolution X-ray images provide better understanding of structure and function of materials, which is critical for the development of new materials with improved properties. This requires bright X-ray sources but also highly efficient and almost perfect x-ray optics. To acquire images, the X-rays must be focused : as in a light microscope. This is not easy as high energy X-rays penetrate most materials unimpeded and cannot be significantly manipulated with conventional lenses. The multilayer Laue lens overcomes this problem. This device is basically a synthetic nanostructure that diffracts X-rays much like a crystal. If shaped the right way, the incident X-rays can all be concentrated in a very small focus.

The synthetic nanostructures are prepared by magnetron […]

April 16th, 2018|General News Feed|

Some superconductors can also carry currents of ‘spin’

From phys.org:

Researchers have shown that certain superconductors—materials that carry electrical current with zero resistance at very low temperatures—can also carry currents of ‘spin’. The successful combination of superconductivity and spin could lead to a revolution in high-performance computing, by dramatically reducing energy consumption.

Spin is a particle’s intrinsic angular momentum, and is normally carried in non-superconducting, non-magnetic materials by individual electrons. Spin can be ‘up’ or ‘down’, and for any given material, there is a maximum length that spin can be carried. In a conventional superconductor electrons with opposite spins are paired together so that a flow of electrons carries zero spin.

A few years ago, researchers from the University of Cambridge showed that it was possible to create electron pairs in which the spins are aligned: up-up or down-down. The spin current can be carried by up-up and down-down pairs moving in opposite directions with a net charge current of zero. The ability to create such a pure spin supercurrent is an important step towards the team’s vision of creating a superconducting computing technology which could use massively less energy than the present silicon-based electronics.

Now, the same researchers have found a set of materials which encourage the pairing of spin-aligned electrons, so that a spin current […]

April 16th, 2018|General News Feed|

Toyoda Gosei achieves high-current operation with vertical GaN power semiconductors

From Semiconductor Today: 

Toyoda Gosei Co Ltd of Kiyosu, Aichi Prefecture, Japan has achieved high-current operation in vertical gallium nitride (GaN) power semiconductor devices.

Power semiconductors are widely used in power converters such as power sources and adaptors for electronic devices. However, simultaneous achievement of both high breakdown voltage and low loss (low conduction loss and switching loss) at high levels has been difficult using conventional silicon due to its material properties.

In contrast, GaN has material properties of high breakdown voltage and low loss, and Toyoda Gosei’s power semiconductors employ a vertical device structure in which electrical current flows vertically from or to the substrate. These changes have enabled a GaN power transistor chip with operating current of more than 50A (claimed to be the highest ever reported for vertical GaN transistors) and high-frequency operation (several megahertz).

Toyoda Gosei says that it will continue development of the power semiconductors for improved reliability, aiming to achieve practical applications in cooperation with semiconductor and electronics manufacturers. Prospective applications include more compact, lighter-weight and higher-efficiency power converters (e.g. DC-DC converters and power control units for automobiles etc) and higher-output high-frequency power sources (e.g. in wireless power supplies).

The new vertical GaN power transistors (MOSFETs) and Schottky […]

April 13th, 2018|General News Feed|

Could holey silicon be the holy grail of electronics?

From phys.org:

Electronics miniaturization has put high-powered computing capability into the hands of ordinary people, but the ongoing downsizing of integrated circuits is challenging engineers to come up with new ways to thwart component overheating.

Scientists at the University of California, Irvine made a breakthrough recently in verifying a new material configuration to facilitate cooling. In a study in the journal Nanotechnology, members of UCI’s Nano Thermal Energy Research Group highlight the attributes of holey silicon, a computer chip wafer with tiny, vertically etched orifices that work to shuttle heat to desired locations.

“We found that heat prefers to travel vertically through but not laterally across holey silicon, which means the material can effectively move the heat from local hot spots to on-chip cooling systems in the vertical direction while sustaining the necessary temperature gradient for thermoelectric junctions in the lateral direction,” said corresponding author Jaeho Lee, UCI assistant professor of mechanical & aerospace engineering.

“This innovation could potentially be ideal for keeping electronic devices such as smartphones cool during operation,” said lead author Zongqing Ren, a graduate student researcher in the NTERG.

He said that lab simulations demonstrated that the cooling effectiveness of holey silicon is at least 400 percent better than chalcogenides, compounds […]

April 13th, 2018|General News Feed|

NIST chip hints at quantum sensors of the future

From New Electronics:

 

A chip upon which laser light interacts with a tiny cloud of atoms has been devised by a team at the National Institute of Standards and Technology (NIST). The idea is that it will serve as a miniature toolkit for measuring important quantities, such as length with quantum precision, with the hope the design could be mass-produced with existing technology.
According to NIST, its prototype chip was used to generate infrared light at a wavelength of 780nm, precisely enough to be used as a length reference for calibrating other instruments. NIST continues that its chip packs the atom cloud and structures for guiding light waves into less than 1cm2, about one ten-thousandth of the volume of other compact devices offering similar measurement precision.

“Compared to other devices that use chips for guiding light waves to probe atoms, our chip increases the measurement precision a hundredfold,” NIST physicist Matt Hummon says. “Our chip currently relies on a small external laser and optics table, but in future designs, we hope to put everything on the chip.”

Many devices use light to probe the quantum states of atoms in a vapour confined in a small cell. Atoms can be highly sensitive to external […]

April 12th, 2018|General News Feed|

Diamond-based circuits can take the heat for advanced applications

From phys.org:

When power generators like windmills and solar panels transfer electricity to homes, businesses and the power grid, they lose almost 10 percent of the generated power. To address this problem, scientists are researching new diamond semiconductor circuits to make power conversion systems more efficient.

A team of researchers from Japan successfully fabricated a key circuit in power conversion systems using hydrogenated diamond (H-diamond.) Furthermore, they demonstrated that it functions at temperatures as high as 300 degrees Celsius. These circuits can be used in diamond-based electronic devices that are smaller, lighter and more efficient than silicon-based devices. The researchers report their findings this week in Applied Physics Letters.

Silicon’s material properties make it a poor choice for circuits in high-power, high-temperature and high-frequency electronic devices. “For the high-power generators, diamond is more suitable for fabricating power conversion systems with a small size and low power loss,” said Jiangwei Liu, a researcher at Japan’s National Institute for Materials Science and a co-author on the paper.

In the current study, researchers tested an H-diamond NOR logic circuit’s stability at high temperatures. This type of circuit, used in computers, gives an output only when both inputs are zero. The circuit consisted of two metal-oxide-semiconductor field-effect transistors (MOSFETs), which are used in […]

April 12th, 2018|General News Feed|

Get Ready For Integrated Silicon Photonics

From Semiconductor Engineering:

Long-haul communications and data centers are huge buyers of photonics components, and that is leading to rapid advances in the technology and opening new markets and opportunities. The industry has to adapt to meet the demands being placed on it and solve the bottlenecks in the design, development and fabrication of integrated silicon photonics.

“Look at the networking bandwidth used across cloud computing, search and social networks,” says Brian Welch, director of product marketing for Luxtera. “These guys run mega data centers and they just consume outrageous amounts of bandwidth — far in excess of all of the other markets put together. The next place that could rival that scale is the 5G rollout for radio.”

But it is not just about bandwidth anymore. Integrated silicon photonics has the ability to fundamentally change some notions of computing. The industry is just beginning to see what may be possible.

The importance of silicon
In the past, photonics was fabricated using specialty fabs, often based on Indium Phosphide (InP). “Silicon has allowed companies to access the larger scale of manufacturing,” asserts Radha Nagarajan, CTO for Inphi. “Silicon uses 8-inch or 12-inch wafers (200mm or 300mm), versus a 3-inch or at most 4-inch wafer (100mm) […]

April 12th, 2018|General News Feed|

Fast, efficient optoelectronic chips to hit market next year

From New Atlas:

MIT spin off company Ayar Labs is combining light and electronics to create faster, more efficient computers. The new optoelectronic chips are designed to speed up data transmission to and from conventional processor chips in a way that will also reduce energy consumption in chip-to-chip communications by 95 percent and could cut overall energy usages by large data firms by up to 50 percent.

Since the invention of the silicon chip 60 years ago, the power of computers has doubled every two years, but the speed at which computer systems work hasn’t shown quite such dramatic progress. The problem is one of data transmission and the bottlenecks that any technology runs into, slowing down the whole to the speed of its most sluggish part.

Think of a computer as like an air passenger system. If you concentrate on the aircraft, airport runway architecture, supply logistics, and air traffic control, it’s easy to speed up travel between, for example, New York and Washington DC to under one hour. That sounds fantastic, but if it takes you two hours to get through security at one hand and another two hours to collect your baggage at the other, then it’s faster to drive.

It’s the […]

April 11th, 2018|General News Feed|