Category Archives: MEMS

Electronic systems that improve vehicle performance; that add comfort and convenience; and that warn, detect, and take corrective measures to keep drivers safe and alert are being added to new cars each year. Consumer demand and government mandates for many of these new systems, along with rising prices for many IC components within them, are expected to raise the automotive IC market 22% this year to a new record high of $28.0 billion (Figure 1).

Over the past several years, the global automotive IC market has experienced some extraordinary swings in growth.  After increasing 11.5% in 2014, the automotive IC market declined 2.5% in 2015, but then rebounded with solid 10.8% growth in 2016.  It is worth noting that the sales decline experienced in 2015 was primarily the result of falling ASPs across all the key automotive IC product categories—microcontrollers, analog ICs, DRAM, flash, and general- and special-purpose logic ICs, which offset steady unit growth for automotive ICs that year.

Figure 1

Figure 1

However, in the second half of 2016, steadily rising ASPs (along with demand for the new automotive systems) helped return the automotive IC market to double-digit growth. In 2017, exceptionally strongincreases in DRAM and flash memory prices are expected to help drive the total automotive IC market to an extraordinary increase of 22.4%.

IC Insights recently revised its IC market outlook for 2017 and now shows DRAM average selling prices rising 50% in 2017, NAND flash ASPs increasing 28%, and the average selling price for automotive special-purpose logic devices increasing 34%. these strong ASPs gains, coupled with ongoing system demand, are driving the strong automotive IC market growth this year (Figure 2).

Figure 2

Figure 2

Collectively, microcontrollers, analog, standard logic, and memory ICs used in automotive applications accounted for only about 8% of total IC marketshare by system type in 2016, but that share is forecast to increase to more than 10% in 2020, when automotive is expected to become the third-largest end-use category for ICs, trailing only the communications and computer segments.   Through 2020, IC Insights anticipates that advanced driver-assistance systems (ADAS) will be the biggest user of automotive ICs.  Various ADAS systems are currently helping cars and drivers remain safe on the road and they are proving to be essential building blocks to semi autonomous and autonomous vehicles that are being proposed for the next decade.

By Paula Doe, SEMI

Autonomous automobiles, smart manufacturing, smart buildings, mobile human health monitoring, and 4G+ communications hardware for connecting all these devices will drive strong 24 percent growth in units and 14 percent in value for the MEMS sector, according to Yole Développement. “These emerging markets will give a noticeable boost to MEMS growth going forward,” says Yole Founder and President Jean Christophe Eloy, who will discuss the changes coming to the sector at SEMICON West 2017, on July 11.

These emerging applications are changing what’s required from MEMS suppliers. We are seeing bigger building blocks with higher value, integration of more functions and more processing power in the package, and increased demand for software intelligence to turn the sensor data into useful information, Eloy notes. This probably also means a shake up in the players, as it’s not clear who will capture the value of this growth opportunity, as the key skills move even more towards integration and software to enable functions.

Emerging smart autos, manufacturing, healthcare and increasingly complex high speed communications will boost MEMS market to more than $25 billion in the next six years. Source: Yole Développement.

Emerging smart autos, manufacturing, healthcare and increasingly complex high speed communications will boost MEMS market to more than $25 billion in the next six years. Source: Yole Développement.

Demand for smart audio, smart visual and more RF

The demand for RF filters required by the increasing complexity of communicating all this data with high-speed 4G/4G+ mobile technology will make RF MEMS BAW filters the fastest-growing segment of the MEMS business, likely seeing some 35 percent compound annual growth, jumping from $2.2 billion in 2017 to a $10.2 billion market in 2022, according to Yole analysts.

Demand for audio processing will also be particularly strong, with 11 percent growth in units for MEMS microphones, increasingly for more sophisticated applications that use the devices in an always-listening capacity, continually sensing what is happening around in the home, in the car or in the factory. That means more processing power and software are needed to detect key sounds form the background noise, and even recognize what they mean. .

Another coming change: MEMS micro speakers will soon finally hit the market. STMicroelectronics is currently making wafers for USound for qualification. “Micro speakers will happen next year,” says Eloy, noting that this will enable a proliferation of small and diffuse audio applications, and will increase demand for more and more sophisticated audio ICs for processing, as audio increasingly becomes a more main used human-machine interface.

Growing opportunity for adding audio value based on MEMS means interest by a host of competing players. Source: Yole Développement.

Growing opportunity for adding audio value based on MEMS means interest by a host of competing players. Source: Yole Développement.

Smarter image sensing will also make its way into more applications, while various types of 3D imaging like ultrasonics, radar, and LIDAR are starting to get traction not only in automotive applications, but also in smartphones for autofocus and for facial recognition for security.

Adding intelligence at the edge

The next generation of sensor technology will also clearly integrate more intelligence. IoT applications are generating immense amounts of data, which needs to be intelligently processed into useful information for local action. However, sending all that data to the cloud and back for processing is often not practical. “Now that we have so much sensor data available ─ not just motion, but also sound, imaging, IR, UV, and other spectra ─ the next opportunity is to add artificial intelligence (AI) or machine learning at the edge, so the sensors report only the selective information required to signal problems that need action,” says Pete Beckman, co-director, Northwestern/Argonne Institute for Science and Engineering, Argonne National Laboratory. Beckman will talk at SEMICON West (July 11-13) about his lab’s open platform that allows researchers to experiment with adding machine learning to sensor nodes.

The Argonne Waggle platform includes a Linux-based single board computer to handle encrypted networking and data caching.  It also pulls sensor data from customized boards or off-the-shelf sensor devices.  The Waggle management (wagman) board controls power and diagnostics.  The third key component is a single board computer focused completely on edge computing, supporting AI and machine learning.  With eight CPU cores and a GPU, the edge processor can be trained to recognize sounds and images or other patterns, using open source software like UC Berkeley’s Caffe deep learning software and the OpenCV computer vision package. “We isolated this part on a separate board to run the newest software available, and out on the leading edge of development, all of this AI software can still be a little buggy,” Beckman notes.

The group is working with the city of Chicago on a network of these smart nodes to monitor things like traffic incidents, air pollution, ice on roads, or potential flooding.  Other researchers are the using the platform to measure pollen and particulates in air to predict asthma outbreaks, or monitor water flow patterns across a prairie site.

Adding intelligence to development

“If the MEMS industry is going to innovate more smartly, we can’t keep doing things the same old way we always have, and the foundries have to do their part to do things differently as well,” notes Tomas Bauer, Silex Microsystems‘ SVP Sales & Business Development, who will discuss Silex’s efforts to use tailored IT systems to speed the development of MEMS devices. Since most innovative MEMS devices depend on developing a whole new wafer process, ramping to stable volume production has often taken years. So Silex has worked on developing information systems to track the wafers through development, with a cockpit view for easy access to all the statistics on the runs and the risk items, immediate notification of potential issues, and more sophisticated queuing and optimization of pathways of development batches to speed throughput in the high-mix fab, Silex’s also uses optical inspection tools during processing so its engineers can roll back the images to see what went wrong. “Instead of trying to standardize the process, we need to find ways to speed the development of the custom process,” Bauer suggests.

At SEMICON West 2017 (July 11-13), the MEMS and Sensors session also features David Horsley from University of California (Davis) on piezoelectric MEMS opportunities, and Thin Film’s Arvind Kamoth  and Princeton’s James Sturm on new technologies for systems integrating sensors and CMOS on flexible substrates.

See the SEMICON West Agenda-at-a-Glance; for best pricing, register now for SEMICON West 2017.

The 63rd annual IEEE International Electron Devices Meeting (IEDM), to be held at the Hilton San Francisco Union Square hotel December 2-6, 2017, has issued a Call for Papers seeking the world’s best original work in all areas of microelectronics research and development.

The paper submission deadline this year is Wednesday, August 2, 2017. For the second year in a row the IEDM submission deadline is about 1½ months later than what had been the norm, reducing the time between paper submissions and publication of the cutting-edge research results for which the conference is known. Authors are asked to submit four-page camera-ready abstracts (instead of the traditional three pages), which will be published as-is in the proceedings.

Only a very limited number of late-news papers will be accepted. Authors are asked to submit late-news abstracts announcing only the most recent and noteworthy developments. The late-news submission deadline is September 11, 2017.

“Based on the success of the later paper-submission deadline last year, we have decided to make it an IEDM tradition,” said Dr. Barbara DeSalvo, Chief Scientist at Leti. “This helps ensure a rich and unique technical program.”

At IEDM each year, the world’s best scientists and engineers in the field of microelectronics gather to participate in a technical program consisting of more than 220 presentations, along with special luncheon presentations and a variety of panels, special sessions, Short Courses, IEEE/EDS award presentations and other events highlighting leading work in more areas of the field than any other conference.

This year special emphasis is placed on the following topics:
Advanced memory technologies
More-than-Moore device concepts
Neuromorphic computing/machine learning
Optoelectronics, photonics, displays and imaging systems
Package-device level interactions
Sensors and MEMS devices for biological/medical applications
Spin for memory and logic
Steep subthreshold devices
Technologies for 5nm and beyond

Overall, papers in the following areas of technology are encouraged:

  • Circuit and Device Interaction
  • Characterization, Reliability and Yield
  • Compound Semiconductor and High-Speed Devices
  • Memory Technology
  • Modeling and Simulation
  • Nano Device Technology
  • Optoelectronics, Displays and Imagers
  • Power Devices
  • Process and Manufacturing Technology
  • Sensors, MEMS and BioMEMS

North America-based manufacturers of semiconductor equipment posted $2.17 billion in billings worldwide in April 2017 (three-month average basis), according to the April Equipment Market Data Subscription (EMDS) Billings Report published today by SEMI.

SEMI reports that the three-month average of worldwide billings of North American equipment manufacturers in April 2017 was $2.17 billion. The billings figure is 4.6 percent higher than the final March 2017 level of $2.08 billion, and is 48.9 percent higher than the April 2016 billings level of $1.46 billion.

“Semiconductor equipment billings levels exceed two billion dollars for the second month in a row,” said Ajit Manocha, president and CEO of SEMI.  “Solid market fundamentals, coupled with strong demand for memory for data storage and processors for smartphones, are fueling significant investments.”

The SEMI Billings report uses three-month moving averages of worldwide billings for North American-based semiconductor equipment manufacturers. Billings figures are in millions of U.S. dollars.
Billings
(3-mo. avg)
Year-Over-Year
November 2016
$1,613.3
25.2%
December 2016
$1,869.8
38.5%
January 2017
$1,859.4
52.3%
February 2017
$1,974.0
63.9%
March 2017 (final)
$2,079.7
73.7%
April 2017 (prelim)
$2,174.5
48.9%

Source: SEMI (www.semi.org), May 2017
SEMI ceased publishing the monthly North America Book-to-Bill report in January 2017. SEMI will continue publish a monthly North American Billings report and issue the Worldwide Semiconductor Equipment Market Statistics (WWSEMS) report in collaboration with the Semiconductor Equipment Association of Japan (SEAJ).

After several years of low and inconsistent growth rates primarily because of intense pricing pressure, the market for semiconductor sensors and actuators finally caught fire in 2016 with several of its largest product categories—acceleration/yaw and magnetic-field sensors and actuator devices—recording strong double-digit sales increases in the year, according to IC Insights’ new 2017 O-S-D Report—A Market Analysis and Forecast for Optoelectronics, Sensors/Actuators, and Discretes.  In addition to the easing of price erosion, substantial unit-shipment growth in sensors and actuators continues to be fed by the spread of intelligent embedded control, new wearable systems, and the expansion of applications connected to the Internet of Things, says the 2017 O-S-D Report.

The new 360-page report shows worldwide sensor sales grew 14% in 2016 to a record-high $7.3 billion, surpassing the previous annual peak of $6.4 billion set in 2015, when revenues increased 3.7%. Actuator sales climbed 19% in 2016 to an all-time high of $4.5 billion from the previous record of $3.8 billion in 2015.  The 2017 O-S-D Report forecasts total sensor sales rising by a compound annual growth rate (CAGR) of 7.5% in the next five years, reaching $10.5 billion in 2021, while actuator dollar volumes are expected to increase by a CAGR of 8.4% to nearly $6.8 billion in the same timeframe.  Figure 1 shows the relative market sizes of the five main product categories in the sensors/actuator segment, along with the projected five-year growth rates for the 2016-2021 forecast period.

The sensor/actuator market ended four straight years of severe price erosion in 2016 and finally benefitted from strong unit growth.  The average selling price (ASP) of sensors and actuators declined by -0.9% in 2016 versus an annual average of -9.3% during the four previous years (2012-2015), says IC Insights’ new O-S-D Report.  All sensor product categories and the large actuator segment registered double-digit sales growth in 2016.  It was the first time in five years that sales growth was recorded in all sensor/actuator product categories, partly due to the easing of price erosion but also because of continued strong unit demand worldwide.  Sensor/actuator shipments grew 17% in 2016 to a record-high of 20.3 billion units from 17.4 billion in 2015, when the volume also increased 17%.

Figure 1

Figure 1

Strong 2016 sales recoveries occurred in acceleration/yaw-rate motion sensors (+15%), magnetic-field sensors and electronic compass chips (+18%), and the miscellaneous other sensor category (+20%) after market declines were registered in 2015. Sales growth also strengthened in pressure sensors, including MEMS microphone chips, (+10%) and actuators (+19%) in 2016.  The new O-S-D Report forecasts sales of acceleration/yaw sensors growing 9% in 2017 to about $3.0 billion, magnetic-field sensors (and compass chips) rising 8% to nearly $2.0 billion, and pressure sensors increasing 8% to $2.7 billion this year.  Actuator sales are projected to grow 8% in 2017 to about $4.9 billion.

About 82% of the sensors/actuators market’s revenues in 2016 came from semiconductors built with microelectromechanical systems (MEMS) technology—meaning pressure sensors, microphone chips, acceleration/yaw motion sensors, and actuators that use MEMS-built transducer structures to initiate physical action in a wide range of devices, including inkjet printer nozzles, microfluidic chips, micro-mirrors, and surface-wave filters for RF signals.  MEMS-built products represented 48% of total sensor/actuator shipments in 2016, or about 9.8 billion units last year.

MEMS-based product sales climbed 15.4% in 2016 to a record-high $9.7 billion after rising 5.1% in 2015 and 5.8% in 2014.   Some inventory corrections and steep ASP erosion in MEMS-built devices have suppressed revenue growth in recent years, but this group of products—like the entire sensors/actuator market—is benefitting from increased demand in new wearable systems, IoT, and the rapid spread of intelligent embedded control, such as autonomous automotive features rolling into cars.  MEMS-based sensors and actuator sales are forecast to rise 7.9% in 2017 to $10.5 billion and grow by a CAGR of 8.0% in the 2016-2021 period to $14.3 billion, says the new O-S-D Report.

EV Group (EVG), a supplier of wafer bonding and lithography equipment for the MEMS, nanotechnology and semiconductor markets, today announced that it has achieved an industry milestone with more than 1100 EVG wafer bonding chambers installed at customer facilities worldwide to date. This milestone cements EVG’s technology and market leadership in wafer bonding, which is an enabling process for volume manufacturing of semiconductor advanced packaging, MEMS, CMOS image sensors, and radio frequency (RF) devices. The EVG 500, EVG 850, GEMINI and ComBond series of wafer bonding solutions, in particular, are seeing strong demand due to their performance and cross-platform compatibility, which allows customers to more easily ramp up their R&D processes to high-volume manufacturing.

Every four seconds, a wafer is bonded with an EVG system. Shown here is a 300-mm bond chamber in an EVG®560 Automated Wafer Bonding System. The EVG560 accepts up to four bond chambers with various configuration options for all bonding processes, including anodic, thermo compression, fusion bonding and LowTemp™ plasma bonding.

Every four seconds, a wafer is bonded with an EVG system. Shown here is a 300-mm bond chamber in an EVG®560 Automated Wafer Bonding System. The EVG560 accepts up to four bond chambers with various configuration options for all bonding processes, including anodic, thermo compression, fusion bonding and LowTemp™ plasma bonding.

“For our high-volume customers, it is essential that they have ready access to industry-proven, cost-effective and high-yielding process solutions. EV Group has closely collaborated with customers and partners for nearly three decades to innovate wafer bonding technology, which has led to the establishment of our technology as the de-facto industry standard for high-volume manufacturing,” stated Hermann Waltl, executive sales and customer support director at EV Group. “Our product offerings span the entire manufacturing chain from R&D and small-scale production environments to full-scale, high-volume production. This enables us to support our customers throughout as they transform new ideas into real-world products.”

EVG’s wafer bonding solutions for adhesive and fusion/hybrid bonding, metal bonding (such as solder and eutectic), and high-vacuum encapsulation undergo continuous innovation in a variety of critical areas, including temperature and process uniformity, vacuum control, wafer alignment and ease of use to ensure a high-yielding and high-throughput bonding process. Manual and semi-automated wafer bonders are fully compatible with EVG production bonding systems, which shortens the development time for customers to bring new innovative devices to market.

For adhesive, solder and eutectic bonding, the EVG500 series of semi-automated wafer bonders and GEMINI series of fully-automated wafer bonders support non-hermetic, cost-efficient encapsulation of CMOS image sensors, surface acoustic wave (SAW) filters for wireless RF chips, and other devices for mobile phones and other high-volume consumer applications. Additionally, tool configurations can be tailored to more demanding bond processes such as hermetic encapsulation for MEMS devices.

For high-vacuum encapsulation bonding, the new EVG ComBond automated high-vacuum wafer bonder provides ultra-high vacuum encapsulation (10-8 mbar) needed for next-generation MEMS devices, such as gyroscopes, microbolometers, and advanced sensors used in autonomous cars, virtual reality headsets and other applications.

For fusion bonding, the EVG850LT and the GEMINI FB automated fusion bonders enable manufacturing of high-accuracy optical devices, image sensors, and engineered substrates such as silicon-on-insulator (SOI), silicon carbide (SiC) and gallium nitride (GaN) for RF, power and other high-speed/high-efficiency devices.

Added Waltl, “EVG is continuously improving our process solutions in order to address wider market applications and more stringent industry requirements. This has paid off for our customers, which in turn has enabled us to maintain our leadership position in the wafer bonding market. Every four seconds, a wafer is bonded with an EVG system. We are proud to bring our expertise gained from this far-reaching installed base to our customers around the world.”

FlexTech’s annual Flexible Electronics Conference and Exhibit – 2017FLEX – is set for the Hyatt Regency Hotel & Spa in Monterey, Calif.  from June 19-22, 2017. Consistently attracting 500+registrants, the event is the premier technology conference for the emerging flexible electronics industry. Twenty-six sessions will cover the landscape of flexible hybrid electronics and printed electronics, including R&D, manufacturing and applications. Short courses and networking events round out 2017FLEX.

According to Zion Research, “global demand for the flexible electronics market was valued at $5.13 billion in 2015 and is expected to generate revenue of $16.5 billion by 2021, growing at a CAGR of slightly above 21 percent between 2016 and 2021.”  Key elements of the market include flex displays, sensors, batteries, and memory. Applications also abound in the automotive, consumer electronics, healthcare, and industrial sectors.

While technology advancement and accelerating to manufacturing are the primary themes of the FLEX Conference, applications and business trends are highlighted on the opening day:

  • Applied Materials Keynote by Brian Shieh, corporate VP and GM, Display Business Group, on the flexible display market
  • Flex, the global EMS provider, and NextFlex, America’s Flexible Hybrid Electronics Manufacturing Institute, on the challenges and solutions for manufacturing flexible and stretchable electronics
  • Libelium on how new IOT platforms that integrate sensors to monitor and control body parameters will lead to better healthcare for billions
  • Experience Co-Creation Partnership on the ten starting points for the development of flexible/hybrid sensors for agriculture and food
  • NovaCentrix on the OE-A Roadmap 2017, giving an outlook on organic and printed electronics developments and prospects
  • Gartner Group on when flexible electronics will reach critical mass

Sessions are planned for FHE manufacturing, standards and reliability, substrates, conductors, inspection, encapsulation and coating, nanoparticle inks, direct write, and 3D printing, among others. Well-known companies will present, such as Molex, Panasonic, Eastman Chemical, and Northrup Grumman, as well as leading universities, and the U.S. Army and U.S. Air Force Research Laboratories.

Among the R&D organizations presenting at 2017FLEX are CEA-LITEN (France), ETRI (South Korea), Flexible Electronics & Display Center (USA), Fraunhofer Institute (Germany), Holst Center (Netherlands), National Research Council (Canada), PARC (USA), and VTT (Finland). Topics of the presentations range from new forms of flexible substrates to TFT and OLED pilot lines to printed health monitoring sensors.

The exhibit floor, short courses and networking opportunities round out the event, as well as many member-only meetings.  FlexTech, the Nano-Bio Manufacturing Consortium (NBMC) and NextFlex hold member and planning meetings for the governing councils, technical councils and technology working groups.  Initiatives in manufacturing, mobile power, e-health, as well as project proposals will be discussed, all buoyed by the information shared during the technical conference.

For more information on 2017FLEX, please visit:  www.semi.org/en/2017-flex

Racyics GmbH announced today it has launched makeChip, a design service platform, developed using GLOBALFOUNDRIES’ 22FDX process technology and supported by Cadence. Available to start-ups, design experts, research institutes, and universities, makeChip is a central gateway to design integrated circuits based on advanced semiconductor technologies.

The platform provides an IT infrastructure with a full set of EDA tool installations and technology data setup such as PDKs, foundation IP, and complex IP. All tools and design data are linked by Racyics’ silicon-proven design flow and project management system. The turnkey environment enables any makeChip customer to realize complex systems on chips (SoCs) in the most advanced technology nodes.

GF’s 22nm FD-SOI technology, 22FDX, provides advantages in power efficiency and production cost. One key factor to a successful design, leveraging the full potential while achieving shortest time-to-market, is the support of a highly experienced design enablement team.

As a part of GF’s FDXcelerator Partner Program, Racyics  makeChip will provide comprehensive support for the most advanced technologies and thus helps smaller players to realize their enormous innovative potential.

“We want to move start-ups, small and medium sized businesses, and academia to the leading-edge of the game. With makeChip, we enable them to quickly execute analog, mixed-signal and digital designs in GF’s 22FDX technology, so they can develop the hardware basis for high-volume applications in the fields of IoT and Industry 4.0,” stated Holger Eisenreich, CEO of Racyics.

“Our 22FDX technology is quickly becoming a platform of choice for market-focused applications that require low power and operational efficiency with an affordability advantage,” said Alain Mutricy, senior vice president of Product Management at GF. “This collaboration with Racyics and Cadence will help lower the barrier of entry for SMEs, start-ups, and academia.”

Access to makeChip includes a complete digital design flow with advanced silicon-proven solutions from Cadence without additional costs for non-commercial academic projects. For commercial projects, different contract agreements will be applied.

“The Cadence full-flow digital solution, is a perfect match for the makeChip design platform. Users are enabled to meet their power, performance and area targets, “ said Jens Werner, Vice President, Technical Field Operation, at Cadence. “The makeChip platform will help to grow design starts in Europe and beyond.”

Racyics provides its in-house 0.4V IP for 22FDX to makeChip customers. It is free of charge in the frame of non-commercial projects and enables platform users to be the first in the world to explore an ultra-low voltage design space and uses its unparalleled potential for energy-efficient operation.

Scientists have greatly expanded the range of functional temperatures for ferroelectrics, a key material used in a variety of everyday applications, by creating the first-ever polarization gradient in a thin film.

The achievement, reported May 10 in Nature Communications by researchers at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), paves the way for developing devices capable of supporting wireless communications in extreme environments, from inside nuclear reactors to Earth’s polar regions.

Ferroelectric materials are prized for having a spontaneous polarization that is reversible by an applied electric field and for the ability to produce electric charges in response to physical pressure. They can function as capacitors, transducers, and oscillators, and they can be found in applications such as transit cards, ultrasound imaging, and push-button ignition systems.

Berkeley Lab scientists created a strain and chemical gradient in a 150-nanometer-thin film of barium strontium titanate, a widely used ferroelectric material. The researchers were able to directly measure the tiny atomic displacements in the material using cutting-edge advanced microscopy at Berkeley Lab, finding gradients in the polarization. The polarization varied from 0 to 35 microcoulombs per centimeter squared across the thickness of the thin-film material.

On the left is a low-resolution scanning transmission electron microscopy (STEM) image of a ferroelectric material that is continuously graded from barium strontium titanate (BSTO, top) to barium titanate (BTO, bottom). The material is grown on a gadolinium scandate (GSO) substrate buffered by a strontium ruthenate (SRO) bottom electrode. To the right are local nanobeam diffraction-based 2D maps of a-axis and c-axis lattice parameters that confirm large strain gradients in the ferroelectric material. The material is promising as electrically-tunable capacitors with extreme temperature stability. Credit: Anoop Damodaran/Berkeley Lab

On the left is a low-resolution scanning transmission electron microscopy (STEM) image of a ferroelectric material that is continuously graded from barium strontium titanate (BSTO, top) to barium titanate (BTO, bottom). The material is grown on a gadolinium scandate (GSO) substrate buffered by a strontium ruthenate (SRO) bottom electrode. To the right are local nanobeam diffraction-based 2D maps of a-axis and c-axis lattice parameters that confirm large strain gradients in the ferroelectric material. The material is promising as electrically-tunable capacitors with extreme temperature stability. Credit: Anoop Damodaran/Berkeley Lab

Tossing out textbook predictions

“Traditional physics and engineering textbooks wouldn’t have predicted this observation,” said study principal investigator Lane Martin, faculty scientist at Berkeley Lab’s Materials Sciences Division and UC Berkeley associate professor of materials and engineering. “Creating gradients in materials costs a lot of energy–Mother Nature doesn’t like them–and the material works to level out such imbalances in whatever way possible. In order for a large gradient like the one we have here to occur, we needed something else in the material to compensate for this unfavorable structure. In this case, the key is the material’s naturally occurring defects, such as charges and vacancies of atoms, that accommodate the imbalance and stabilize the gradient in polarization.”

Creating a polarization gradient had the beneficial effect of expanding the temperature range for optimal performance by the ferroelectric material. Barium titanate’s function is strongly temperature-dependent with relatively small effects near room temperature and a large, sharp peak in response at around 120 degrees Celsius. This makes it hard to achieve well-controlled, reliable function as the temperature varies beyond a rather narrow window. To adapt the material to work for applications at and around room temperature, engineers tune the chemistry of the material, but the range of temperatures where the materials are useful remains relatively narrow.

“The new polarization profile we have created gives rise to a nearly temperature-insensitive dielectric response, which is not common in ferroelectric materials,” said Martin. “By making a gradient in the polarization, the ferroelectric simultaneously operates like a range or continuum of materials, giving us high-performance results across a 500-degree Celsius window. In comparison, standard, off-the-shelf materials today would give the same responses across a much smaller 50-degree Celsius window.”

Beyond the obvious expansions to hotter and colder environments, the researchers noted that this wider temperature range could shrink the number of components needed in electronic devices and potentially reduce the power draw of wireless phones.

“The smartphone I’m holding in my hand right now has dielectric resonators, phase shifters, oscillators–more than 200 elements altogether–based on similar materials to what we studied in this paper,” said Martin. “About 45 of those elements are needed to filter the signals coming to and from your cell phone to make sure you have a clear signal. That’s a huge amount of real estate to dedicate to one function.”

Because changes in temperature alter the resonance of the ferroelectric materials, there are constant adjustments being made to match the materials to the wavelength of the signals sent from cell towers. Power is needed to tune the signal, and the more out of tune it is, the more power the phone needs to use to get a clear signal for the caller. A material with a polarization gradient capable operating over large temperatures regimes could reduce the power needed to tune the signal.

Faster detectors enable new imaging techniques

Understanding the polarization gradient entailed the use of epitaxial strain, a strategy in which a crystalline overlayer is grown on a substrate, but with a mismatch in the lattice structure. This strain engineering technique, commonly employed in semiconductor manufacturing, helps control the structure and enhance performance in materials.

Recent advances in electron microscopy have allowed researchers to obtain atomic-scale structural data of the strained barium strontium titanate, and to directly measure the strain and polarization gradient.

“We have established a way to use nanobeam scanning diffraction to record diffraction patterns from each point, and afterwards analyze the datasets for strain and polarization data,” said study co-author Andrew Minor, director of the National Center for Electron Microscopy at Berkeley Lab’s Molecular Foundry, a DOE Office of Science User Facility. “This type of mapping, pioneered at Berkeley Lab, is both new and very powerful.”

Another key factor was the speed of the detector, Minor added. For this paper, data was obtained at a rate of 400 frames per second, an order of magnitude faster than the 30-frame-per-second rate from just a few years ago. This technique is now available for users at the Foundry.

“We’re seeing a revolution in microscopy related to the use of direct electron detectors that is changing many fields of research,” said Minor, who also holds an appointment as a UC Berkeley professor of materials science and engineering. “We’re able to both see and measure things at a scale that was hard to imagine until recently.”

Altair Semiconductor (altair-semi.com), a provider of LTE chipsets, today announced that it has become an Associate Member of the GSMA, with a focus on accelerating the delivery of new connected devices and services in the Internet of Things (IoT) space. The GSMA represents the interests of mobile operators worldwide, uniting nearly 800 mobile operators and 300 companies in the broader mobile ecosystem.

Altair plays a pivotal role in actualizing the Internet of Things with a portfolio of low-cost and power-efficient LTE chipsets. The company provides secure and robust cellular connectivity for a range of IoT applications. It recently announced the ALT1250 dual-mode CAT-M1 and NB1 IoT chipset that features ultra-low power consumption, integrated GNSS location services and embedded hardware-based security features.

“We’re pleased to welcome Altair to the GSMA,” said Gregory Geodjenian, Director of Membership for the GSMA. “Altair is among the leading players in cellular IoT, and we look forward to the company taking an active role in our industry work.”

With a portfolio supporting a wide range of LTE categories and use cases – from cutting edge, high-speed broadband equipment to ultra-low power, IoT-optimized devices – Altair’s LTE and IoT connectivity solutions are used by the world’s leading operators, OEMs and ODMs.

“Joining the GSMA provides Altair with the platform to enhance and strengthen our global profile, becoming part of a community of industry leaders for potential collaboration and strategic partnerships,” said Eran Eshed, Co-founder and VP of Worldwide Sales and Marketing for Altair. “Altair is in a strong market position to drive the development and adoption of cellular-based IoT solutions.”