Category Archives: Applications

By Emir Demircan, Senior Manager Advocacy and Public Policy, SEMI Europe

Electronic manufacturing is becoming cool to today’s youth. STEM skills are hot in the global job market – though the number of females pursuing a STEM education continues to lag. Work-based learning is key to mastering new technologies. And the electronics industry needs a global talent pipeline more than ever.

These were key highlights from a SEMI Member Forum in December that brought together industry representatives and students in Dresden to weigh in on job-skills challenges facing the electronics manufacturers and solutions for the industry to consider. Here are the takeaways:

1) Electronics is much more than manufacturing

For many years, working in the manufacturing industry was not an appealing prospect for millennials. This picture is certainly changing. The pivotal role of electronics manufacturing in helping solve grand societal challenges in areas such as the environment, healthcare and urban mobility is reaffirmed by countries around the world. Electronics is the lifeblood of game-changing technologies such as autonomous driving, AI, IoT, and VR/AR, enticing more young employees into careers in research, design, technology development, production, cyber security and international business, and in disciplines ranging from engineering and data analytics to software development and cyber security.

What’s more, the drudgery of many factory jobs is disappearing thanks to automation, digitization and robotization. According to CEDEFOP, the European Centre for the Development of Vocational Training, low-skilled jobs in electro-engineering and machine operations/assembly in the European Union (EU) is projected to decrease 6.98 percent and 2.03 percent, respectively, between 2015 and 2025.

In parallel, the industry will need more high-skilled workers. For instance, within the same period, CEDEFOP forecasts a 12.51 percent increase in jobs for EU researchers and engineers. Soft skills will see high demand too. As the electronics industry continues to globalize and drive the integration of vertical technologies, workers proficient in communicating in an international environment, leading multicultural teams, developing tailor-made solutions and making data-driven decisions will see higher demand.

2) STEM skills will remain under the spotlight

Continuous innovation is the oxygen of the electronics manufacturing industry, powering the development of highly customized solutions by workers with technical expertise in chemistry, materials, design, mechanics, production and many other fields. In addition, capabilities such as smart manufacturing require workers with growing technical sophistication in areas such as software, information and communications technology (ICT) and data analytics, stiffening the challenge the electronics industry faces in finding skilled workers. Little wonder that employers in Europe struggle to build a workforce with the right technical expertise. The findings of the study “Encouraging STEM Studies for the Labour Market” conducted by the European Parliament underscores the difficulty of hiring enough workers with adequate STEM skills:

  • The proportion of STEM students is not rising at the European level and the underrepresentation of women persists.
  • Businesses are expected to produce about 7 million new STEM jobs, an uptick of 8 percent, between 2013 and 2025 in Europe.

3) The women-in-tech gap is becoming more persistent 

The global manufacturing industry suffers from strikingly low female participation in STEM education and careers. According to UNSECO, in Europe and North America, the number of female graduates in STEM is generally low. For instance, women make up just 19 percent of engineers in Germany and the U.S. The European Parliament study confirms that STEM employment remains stubbornly male-dominated, with women filling just 24 percent of science and engineering jobs and 15 percent of science and engineering associate positions in Europe. According to an article by Guardian, a mere 16 percent of computer science undergraduates in the United Kingdom and the U.S. are female. This yawning gender gap is a deep concern for electronics manufacturing companies in Europe, hampering innovation in a sector that relies heavily on diversity and inclusion and shrinks the talent pipeline critical to remaining competitive.

4) Coping with new technologies: work-based learning is the key

The evolution of the electronics industry since the 1980s has been swift. PCs emerged largely as islands of communication, then became networked. Networking bred the proliferation of social platforms and mobile devices and, today, is giving rise to IoT. Education curricula in Europe, however, have not matured at the same pace, opening a gap between the worlds of industry and education and imposing a formidable school-to-work transition for many young graduates. Work-based learning, which helps students develop the knowledge and practical job skills needed by business, is one solution. The industry reports that work-based learning is vital to remaining competitive in the long run. Innovative dual-learning programmes, apprenticeships and industrial master’s and doctorates are shining examples that are already paying off in some parts of Europe. Such work-based learning models can be extended as a common pillar of education in Europe.

5) A global industry needs a global talent pipeline

The electronics value chain workforce needs an international and multicultural talent pipeline, chiefly spanning the U.S., Europe and Asia. However, many European manufacturers, in particular small and medium enterprises (SMEs), report that building an international workforce remains a challenge due to employment and immigration law barriers as well as cultural and linguistic differences. The EU’s Blue Card initiative, designed to facilitate hiring beyond Europe, is a step in the right direction. Nevertheless, with the exception of Germany, EU member states have made little or no use of the EU Blue Card scheme.

SEMI drives sector-wide initiatives on workforce development

Understanding the urgency, SEMI is accelerating its workforce development activities at global level. Contributing to this initiative, the SEMI talent pipeline Forum in Dresden served as an effective platform for the industry to share its challenges and opportunities with students at various education levels. Led by industry representatives, the sessions enabled the exchange of workforce-development best practices and paved the way for further collaboration among industry, academia and government in Europe. For example, in the Career Café session, students networked with hiring managers. Other workforce development initiatives include:

To help position the skills challenges faced by SEMI members high on the public policy agenda, SEMI in 2017 joined several policy groups including Digital Skills and Jobs Coalition and Expert Group on High-Tech Skills. Last year SEMI also launched Women in Tech, an initiative that convenes industry leaders to help increase female representation in the sector. SEMI also educates its members about key EU resources such as the Blue Card and Digital Opportunity Internship programmes aimed at hiring international talent. In 2018, SEMI will reach out to even more young people through its High Tech U programme to raise awareness of careers in electronics. SEMICON Europa 2018 will host dedicated talent pipeline sessions to help the industry tackle its skills challenges. ISS Europe 2018 sessions on Gaining, Training and Retaining World Class Talent will disseminate best practices to the wider industry. Also this year, SEMI Europe plans to start a new advisory group, “Workforce 4.0,” dedicated to bringing together human resources leaders in the sector to give the electronics manufacturing industry a stronger voice on workforce development.

 

The internet of things is coming, that much we know. But still it won’t; not until we have components and chips that can handle the explosion of data that comes with IoT. In 2020, there will already be 50 billion industrial internet sensors in place all around us. A single autonomous device – a smart watch, a cleaning robot, or a driverless car – can produce gigabytes of data each day, whereas an airbus may have over 10 000 sensors in one wing alone.

Two hurdles need to be overcome. First, current transistors in computer chips must be miniaturized to the size of only few nanometres; the problem is they won’t work anymore then. Second, analysing and storing unprecedented amounts of data will require equally huge amounts of energy. Sayani Majumdar, Academy Fellow at Aalto University, along with her colleagues, is designing technology to tackle both issues.

Majumdar has with her colleagues designed and fabricated the basic building blocks of future components in what are called “neuromorphic” computers inspired by the human brain. It’s a field of research on which the largest ICT companies in the world and also the EU are investing heavily. Still, no one has yet come up with a nano-scale hardware architecture that could be scaled to industrial manufacture and use.

“The technology and design of neuromorphic computing is advancing more rapidly than its rival revolution, quantum computing. There is already wide speculation both in academia and company R&D about ways to inscribe heavy computing capabilities in the hardware of smart phones, tablets and laptops. The key is to achieve the extreme energy-efficiency of a biological brain and mimic the way neural networks process information through electric impulses,” explains Majumdar.

The probe-station device (the full instrument, left, and a closer view of the device connection, right) which measures the electrical responses of the basic components for computers mimicking the human brain. The tunnel junctions are on a thin film on the substrate plate. Credit: Tapio Reinekoski

The probe-station device (the full instrument, left, and a closer view of the device connection, right) which measures the electrical responses of the basic components for computers mimicking the human brain. The tunnel junctions are on a thin film on the substrate plate. Credit: Tapio Reinekoski

Basic components for computers that work like the brain

In their recent article in Advanced Functional Materials, Majumdar and her team show how they have fabricated a new breed of “ferroelectric tunnel junctions”, that is, few-nanometre-thick ferroelectric thin films sandwiched between two electrodes. They have abilities beyond existing technologies and bode well for energy-efficient and stable neuromorphic computing.

The junctions work in low voltages of less than five volts and with a variety of electrode materials – including silicon used in chips in most of our electronics. They also can retain data for more than 10 years without power and be manufactured in normal conditions.

Tunnel junctions have up to this point mostly been made of metal oxides and require 700 degree Celsius temperatures and high vacuums to manufacture. Ferroelectric materials also contain lead which makes them – and all our computers – a serious environmental hazard.

“Our junctions are made out of organic hydro-carbon materials and they would reduce the amount of toxic heavy metal waste in electronics. We can also make thousands of junctions a day in room temperature without them suffering from the water or oxygen in the air”, explains Majumdar.

What makes ferroelectric thin film components great for neuromorphic computers is their ability to switch between not only binary states – 0 and 1 – but a large number of intermediate states as well. This allows them to ‘memorise’ information not unlike the brain: to store it for a long time with minute amounts of energy and to retain the information they have once received – even after being switched off and on again.

We are no longer talking of transistors, but ‘memristors’. They are ideal for computation similar to that in biological brains. Take for example the Mars 2020 Rover about to go chart the composition of another planet. For the Rover to work and process data on its own using only a single solar panel as an energy source, the unsupervised algorithms in it will need to use an artificial brain in the hardware.

“What we are striving for now, is to integrate millions of our tunnel junction memristors into a network on a one square centimetre area. We can expect to pack so many in such a small space because we have now achieved a record-high difference in the current between on and off-states in the junctions and that provides functional stability. The memristors could then perform complex tasks like image and pattern recognition and make decisions autonomously,” says Majumdar.

Semtech Corporation (Nasdaq:SMTC), a supplier of high performance analog and mixed-signal semiconductors and advanced algorithms, announced its next generation LoRa devices and wireless radio frequency (RF) technology (LoRa Technology) chipsets enabling innovative LPWAN use cases for consumers with its advanced technology. Addressing the need for cost-effective and reliable sensor-to-cloud connectivity in any type of RF environment, the new features and capabilities will significantly improve the performance and capability of Internet of Things (IoT) sensor applications that demand ultra-low power, small form factor and long range wireless connectivity with a shortened product development cycle.

The next generation LoRa radios extends Semtech’s link budget by 20% with a 50% reduction in receiver current (4.5 mA) and a high power +22 dBm option. This extends battery life of LoRa-based sensors up to 30%, which reduces the frequency of battery replacement. The extended connectivity range, with the ability to reach deep indoor and outdoor sensor locations, will create new markets as different types of verticals integrate LoRa Technology in their IoT applications including healthcare and pharmaceuticals, media and advertising, logistics/shipping, and asset tracking.

In addition, the new platform has a command interface that simplifies radio configuration and shortens the development cycle, needing only 10 lines of code to transmit or receive a packet, which will allow users to focus on applications. The small footprint, 45% less than the current generation, is highly configurable to meet different application requirements utilizing the global LoRaWAN open standard. The chipsets also supports FSK modulation to allow compatibility with legacy protocols that are migrating to the LoRaWAN™ open protocol for all the performance benefits LoRa Technology provides.

“LPWAN IoT applications are going through a massive transformation, shifting from trials to large deployments in smart cities, buildings, healthcare, logistics, and agriculture,” said Marc Pegulu, Vice President and General Manager for Semtech’s Wireless and Sensing Products Group. “LoRa Technology enables an infinite amount of IoT use cases as Semtech pushes for the last mile of connectivity and reinforces its position as the defacto platform for LPWAN.”

ON Semiconductor (Nasdaq: ON) has joined the global Charging Interface Initiative e.V. (CharIN) ecosystem with the goals of promoting standards for charging systems in electric vehicles (EV), creating requirements for the evolution of EV charging systems and developing a certification system for manufacturers to implement charging systems into their products.

ON Semiconductor has all the core technologies for vehicle electrification, particularly the company’s extensive automotive qualified power management portfolio including: IGBTs, high voltage gate drivers, super junction rectifiers, high voltage MOSFETs, high voltage DC-DC converters, as well as Wide Band Gap (WBG) devices in Silicon Carbide (SiC) and Gallium Nitride (GaN) for next generation solutions. Beyond silicon development, investments in advanced packaging include: high power modules, single/dual sided cooled and dual sided direct cooled packages. With sensing, communication and analog solutions, ON Semiconductor has nearly all the components for current and future EV charging infrastructure needs.

“At ON Semiconductor, our core business is Power Management, and we support virtually every requirement with products that range from low drop-out regulators, to switched mode power supplies to sophisticated power management ICs (PMICs), positioning the company as an unrivaled supplier of power solutions for the rapidly emerging EV and hybrid electric vehicle market,” said Ali Husain, senior manager, power conversion and motor control solutions at ON Semiconductor. “We are seeing a ramp-up of our IGBT modules and FETs for electric vehicle charger designs. We expect next generation semiconductor materials such as silicon carbide and gallium nitride to drive improving power density and efficiency. We look forward to bringing this expertise to the CharIN ecosystem and collaborating with other industry leaders to create a Combined Charging System and supporting the continued evolution of EV charging infrastructure.”

As automotive manufacturers turn to next generation semiconductor materials to improve power density and efficiency in hybrid and electric vehicles, ON Semiconductor’s 1200V silicon carbide power devices and 650V gallium nitride power devices provide market leading solutions. These solutions provide higher power efficiency and power density while keeping weight to a minimum.

“We are excited to have ON Semiconductor collaboration in our efforts,” said Claas Bracklo, chairman of CharIN e.V. “Their broad portfolio of power, analog and communication silicon products, system design expertise, and relationships with leading companies in both the automotive and industrial markets complement and supplement the already-strong CharIN roster of members and partners.”

A team of physicists, headed by the U.S. Naval Research Laboratory (NRL), have demonstrated the means to improve the optical loss characteristics and transmission efficiency of hexagonal boron nitride devices, enabling very small lasers and nanoscale optics.

Image shows directly measured polaritons propagating through a flake of Hexagonal boron nitride (hBN). This material has been identified as an ideal substrate for two-dimensional materials research while also recently being demonstrated as an exciting optical material for infrared nanophotonics. Credit: (US Naval Research Laboratory)

Image shows directly measured polaritons propagating through a flake of Hexagonal boron nitride (hBN). This material has been identified as an ideal substrate for two-dimensional materials research while also recently being demonstrated as an exciting optical material for infrared nanophotonics. Credit: (US Naval Research Laboratory)

“The applications for this research are considerably broad,” said Dr. Alexander J. Giles, research physicist, NRL Electronics Science and Technology Division. “By confining light to very small dimensions, nanophotonic devices have direct applications for use in ultra-high resolution microscopes, solar energy harvesting, optical computing and targeted medical therapies.”

Hexagonal boron nitride (hBN) forms an atomically thin lattice consisting of boron and nitrogen atoms. This material has recently been demonstrated as an exciting optical material for infrared nanophotonics and is considered an ‘ideal substrate’ for two-dimensional materials.

While previous work demonstrated that natural hBN supports deeply sub-diffractional hyperbolic phonon polaritons desired for applications, such as, sub-diffractional optical imaging (so-called ‘hyperlensing’), energy conversion, chemical sensing, and quantum nanophotonics, limited transmission efficiencies continue to persist.

“We have demonstrated that the inherent efficiency limitations of nanophotonics can be overcome through the careful engineering of isotopes in polar semiconductors and dielectric materials,” Giles said.

Naturally occurring boron is comprised of two isotopes, boron-10 and boron-11, lending a 10 percent difference in atomic masses. This difference results in substantial losses due to phonon scattering, limiting the potential applications of this material. The research team at NRL has engineered greater than 99 percent isotopically pure samples of hBN, meaning they consist almost entirely of either boron-10 or boron-11 isotopes.

This approach results in a dramatic reduction in optical losses, resulting in optical modes that travel up to three times farther and persist for up to three times longer than natural hBN. These long-lived vibrational modes not only enable immediate advances specific to hBN – near field optics and chemical sensing – but also provide a strategic approach for other materials systems to exploit and build upon.

“Controlling and manipulating light at nanoscale, sub-diffractional dimensions is notoriously difficult and inefficient,” said Giles. “Our work represents a new path forward for the next generation of materials and devices.”

The Semiconductor Industry Association (SIA), representing U.S. leadership in semiconductor manufacturing, design, and research, today announced worldwide sales of semiconductors reached $37.7 billion for the month of November 2017, an increase of 21.5 percent compared to the November 2016 total of $31.0 billion and 1.6 percent more than the October 2017 total of $37.1 billion. All major regional markets posted both year-to-year and month-to-month sales increases in November, with the Americas market leading the way. All monthly sales numbers are compiled by the World Semiconductor Trade Statistics (WSTS) organization and represent a three-month moving average.

“The global semiconductor industry reached another key milestone in November, notching its highest-ever monthly sales, and appears poised to reach $400 billion in annual sales for the first time,” said SIA President & CEO John Neuffer. “Global market growth continues to be led by sales of memory products, but sales of all other major semiconductor categories also increased both month-to-month and year-to-year in November. All regional markets also experienced growth in November, with the Americas continuing to post the strongest gains.”

Regionally, year-to-year sales increased in the Americas (40.2 percent), Europe (18.8 percent), China (18.5 percent), Asia Pacific/All Other (16.2 percent), and Japan (10.6 percent). Month-to-month sales increased in the Americas (2.6 percent), China (2.1 percent), Europe (1.8 percent), Asia Pacific/All Other (0.5 percent), and Japan (0.3 percent).

To find out how to purchase the WSTS Subscription Package, which includes comprehensive monthly semiconductor sales data and detailed WSTS Forecasts, please visit http://www.semiconductors.org/industry_statistics/wsts_subscription_package/. For detailed data on the global and U.S. semiconductor industry and market, consider purchasing the 2017 SIA Databook: https://www.semiconductors.org/forms/sia_databook/.

Nov 2017

Billions

Month-to-Month Sales                              

Market

Last Month

Current Month

% Change

Americas

8.54

8.77

2.6%

Europe

3.37

3.43

1.8%

Japan

3.20

3.21

0.3%

China

11.65

11.90

2.1%

Asia Pacific/All Other

10.33

10.39

0.5%

Total

37.09

37.69

1.6%

Year-to-Year Sales                         

Market

Last Year

Current Month

% Change

Americas

6.25

8.77

40.2%

Europe

2.88

3.43

18.8%

Japan

2.90

3.21

10.6%

China

10.04

11.90

18.5%

Asia Pacific/All Other

8.94

10.39

16.2%

Total

31.02

37.69

21.5%

Three-Month-Moving Average Sales

Market

Jun/Jul/Aug

Sep/Oct/Nov

% Change

Americas

7.55

8.77

16.1%

Europe

3.22

3.43

6.4%

Japan

3.13

3.21

2.6%

China

11.08

11.90

7.4%

Asia Pacific/All Other

9.98

10.39

4.0%

Total

34.96

37.69

7.8%

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.”

STMicroelectronics (NYSE:STM) and USound, a fast-growing audio company, have delivered the first silicon micro-speakers resulting from their technology collaboration announced last year. Engineering samples are now with lead customers, and trade demonstrations will take place during CES 2018, in Las Vegas.

These extremely small speakers, expected to be the thinnest in the world and less than half the weight of conventional speakers, enable wearable tech such as earphones, over-the-ear headphones, or Augmented-Reality/Virtual-Reality (AR/VR) headgear to become even more compact and comfortable. Their extremely low power consumption saves extra weight and size by allowing smaller batteries, and unlike conventional speakers they generate negligible heat.

As MEMS (Micro Electro-Mechanical Systems) devices, the speakers are leveraging technology that has already revolutionized the capabilities of smartphones and wearables. High-performing MEMS motion sensors, pressure sensors, and microphones built on silicon chips are the critical enablers for context sensing, navigation, tracking, and other features that mobile users now rely on every day. With MEMS advancements now coming to speakers, designers can further miniaturize the audio subsystem, reduce power consumption, and create innovative features like 3D sound. MEMS-industry analyst Yole Développement values the overall micro-speakers market at $8.7 billion[1] currently, and expects MEMS manufacturers to capture share with silicon-based devices.

“This successful project combines USound’s design flair and ST’s extensive investment in MEMS expertise and processes, including our advanced thin-film piezo technology PeTra (Piezo-electric Transducer),” said Anton Hofmeister, Vice President and GM of MEMS Microactuators Division, STMicroelectronics. “Together, we are winning the race to commercialize MEMS micro-speakers by delivering a more highly miniaturized, efficient, and better-performing solution leveraging the advantages of piezo-actuation.”

“ST has provided the production expertise and manufacturing muscle to realize our original concept as a pace-setting, advanced product ready for consumer-market opportunities,” said Ferruccio Bottoni, CEO of USound. “These tiny speakers are now poised to change the design of audio and hearable products, and open up new opportunities to develop creative audio functionalities.”

In addition to applications in mobiles, audio accessories, and wearables, the new piezo-actuated silicon speakers support innovation in a wide variety of hearable electronics, including home digital assistants, media players, and IoT (Internet-of-Things) devices.

USound will demonstrate prototype AR/VR glasses containing multiple MEMS speakers per side, to invited guests at ST’s private suite during CES 2018. The demo will leverage the speakers’ ultra-thin form factor, low weight, and high sound quality to show how miniaturized audio systems can deliver outstanding experiences, and advanced features such as beam forming for private audio, within the extremely tight size, weight, and power constraints imposed by glasses and other wearables.

In today’s “internet of things,” devices connect primarily over short ranges at high speeds, an environment in which surface acoustic wave (SAW) devices have shown promise for years, resulting in the shrinking size of your smartphone. To obtain ever faster speeds, however, SAW devices need to operate at higher frequencies, which limits output power and can deteriorate overall performance. A new SAW device looks to provide a path forward for these devices to reach even higher frequencies.

A team of researchers in China has demonstrated a SAW device that can achieve frequencies six times higher than most current devices. With embedded interdigital transducers (IDTs) on a layer of combined aluminum nitride and diamond, the team’s device was also able to boost output significantly. Their results are published this week in Applied Physics Letters, from AIP Publishing.

“We have found the acoustic field distribution is quite different for the embedded and conventional electrode structures,” said Jinying Zhang, one of the paper’s authors. “Based on the numerical simulation analysis and experimental testing results, we found that the embedded structures bring two benefits: higher frequency and higher output power.”

Surface acoustic wave devices transmit a high-frequency signal by converting electric energy to acoustic energy. This is often done with piezoelectric materials, which are able to change shape in the presence of an electric voltage. IDT electrodes are typically placed on top of piezoelectric materials to perform this conversion.

Ramping up the operational frequency of IDTs — and the overall signal speed — has proven difficult. Most current SAW devices top out at a frequency of about 3 gigahertz, Zhang said, but in principle it is possible to make devices that are 10 times faster. Higher frequencies, however, demand more power to overcome the signal loss, and in turn, some features of the IDTs need to be increasingly small. While a 30 GHz device could transmit a signal more quickly, its operational range becomes limited.

“The major challenge is still the fabrication of the IDTs with such small feature sizes,” Zhang said. “Although we made a lot of efforts, there are still small gaps between the side walls of the electrodes and the piezoelectric materials.”

To ensure that the transducers had the proper feature size, Zhang’s team needed a material with a high acoustic velocity, such as diamond. They then coupled diamond, a material that changes its shape very little with electric voltage, with aluminum nitride, a piezoelectric material, and embedded the IDT inside their new SAW device.

The resulting device operated at a frequency of 17.7 GHz and improved power output by 10 percent compared to conventional devices using SAWs.

“The part which surprised us most is that the acoustic field distribution is quite different for the embedded and conventional electrode structures,” Zhang said. “We had no idea at all about it before.”

Zhang said she hopes this research will lead to SAW devices used in monolithic microwave integrated circuits (MMICs), low-cost, high-bandwidth integrated circuits that are seeing use in a variety of forms of high speed communications, such as cell phones.

The coldest chip in the world


December 20, 2017

Physicists at the University of Basel have succeeded in cooling a nanoelectronic chip to a temperature lower than 3 millikelvin. The scientists from the Department of Physics and the Swiss Nanoscience Institute set this record in collaboration with colleagues from Germany and Finland. They used magnetic cooling to cool the electrical connections as well as the chip itself. The results were published in the journal Applied Physics Letters.

Even scientists like to compete for records, which is why numerous working groups worldwide are using high-tech refrigerators to reach temperatures as close to absolute zero as possible. Absolute zero is 0 kelvin or -273.15°C. Physicists aim to cool their equipment to as close to absolute zero as possible, because these extremely low temperatures offer the ideal conditions for quantum experiments and allow entirely new physical phenomena to be examined.

A chip with a Coulomb blockade thermometer on it is prepared for experiments at extremely low temperatures. Credit: University of Basel, Department of Physics

A chip with a Coulomb blockade thermometer on it is prepared for experiments at extremely low temperatures. Credit: University of Basel, Department of Physics

Cooling by turning off a magnetic field

The group led by Basel physicist Professor Dominik Zumbühl had previously suggested utilizing the principle of magnetic cooling in nanoelectronics in order to cool nanoelectronic devices to unprecedented temperatures close to absolute zero. Magnetic cooling is based on the fact that a system can cool down when an applied magnetic field is ramped down while any external heat flow is avoided. Before ramping down, the heat of magnetization needs to be removed with another method to obtain efficient magnetic cooling.

A successful combination

This is how Zumbühl’s team succeeded in cooling a nanoelectronic chip to a temperature below 2.8 millikelvin, thereby achieving a new low temperature record. Dr Mario Palma, lead author of the study, and his colleague Christian Scheller successfully used a combination of two cooling systems, both of which were based on magnetic cooling. They cooled all of the chip’s electrical connections to temperatures of 150 microkelvin – a temperature that is less than a thousandth of a degree away from absolute zero.

They then integrated a second cooling system directly into the chip itself, and also placed a Coulomb blockade thermometer on it. The construction and the material composition enabled them to magnetically cool this thermometer to a temperature almost as low as absolute zero as well.

“The combination of cooling systems allowed us to cool our chip down to below 3 millikelvin, and we are optimistic than we can use the same method to reach the magic 1 millikelvin limit,” says Zumbühl. It is also remarkable that the scientists are in a position to maintain these extremely low temperatures for a period of seven hours. This provides enough time to conduct various experiments that will help to understand the properties of physics close to absolute zero.