Category Archives: MEMS

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.

The year-end update to the SEMI World Fab Forecast report reveals 2017 spending on fab equipment investments will reach an all-time high of $57 billion. High chip demand, strong pricing for memory, and fierce competition are driving the high-level of fab investments, with many companies investing at previously unseen levels for new fab construction and fab equipment. See figure 1.

Figure 1

Figure 1

The SEMI World Fab Forecast data shows fab equipment spending in 2017 totaling US$57 billion, an increase of 41 percent year-over-year (YoY). In 2018, spending is expected to increase 11 percent to US$63 billion.

While many companies, including Intel, Micron, Toshiba (and Western Digital), and GLOBALFOUNDRIES increased fab investments for 2017 and 2018, the strong increase reflects spending by just two companies and primarily one region.

SEMI data shows a surge of investments in Korea, due primarily to Samsung, which is expected to increase its fab equipment spending by 128 percent in 2017, from US$8 billion to US$18 billion. SK Hynix also increased fab equipment spending, by about 70 percent, to US$5.5 billion, the largest spending level in its history. While the majority of Samsung and SK Hynix spending remains in Korea, some will take place in China and the United States. Both Samsung and SK Hynix are expected to maintain high levels of investments in 2018. See figure 2.

Figure 2

Figure 2

In 2018, China is expected to begin equipping many fabs constructed in 2017. In the past, non-Chinese companies accounted for most fab investments in China. For the first time, in 2018 Chinese-owned device manufacturers will approach parity, spending nearly as much on fab equipment as their non-Chinese counterparts. In 2018, Chinese-owned companies are expected to invest about US$5.8 billion, while non-Chinese will invest US$6.7 billion. Many new companies such as Yangtze Memory Technology, Fujian Jin Hua, Hua Li, and Hefei Chang Xin Memory are investing heavily in the region.

Historic highs in equipment spending in 2017 and 2018 reflect growing demand for advanced devices. This spending follows unprecedented growth in construction spending for new fabs also detailed in the SEMI World Fab Forecast report. Construction spending will reach all-time highs with China construction spending taking the lead at US$6 billion in 2017 and US$6.6 billion in 2018, establishing another record: no region has ever spent more than US$6 billion in a single year for construction.

Scientists at Tokyo Institute of Technology (Tokyo Tech) and their research team involving researchers of JASRI, Osaka University, Nagoya Institute of Technology, and Nara Institute of Science and Technology have just developed a novel approach to determine and visualize the three-dimensional (3D) structure of individual dopant atoms using SPring-8. The technique will help improve the current understanding of the atomic structures of dopants in semiconductors correlated with their electrical activity and thus help support the development of new manufacturing processes for high-performance devices.

Using a combination of spectro-photoelectron holography, electrical property measurements, and first-principles dynamics simulations, the 3D atomic structures of dopant impurities in a semiconductor crystal were successfully revealed. The need for a better understanding of the atomic structures of dopants in semiconductors had been long felt, mainly because the current limitations on active dopant concentrations result from the deactivation of excess dopant atoms by the formation of various types of clusters and other defect structures.

Soft X-rays excite the core level electrons, leading to the emission of photoelectrons from various atoms, whose waves are then scattered by the surrounding atoms. The interference pattern between the scattered and direct photoelectron waves creates the photoelectron hologram, which may then be captured with an electron analyzer. Credit: Nano Letters

Soft X-rays excite the core level electrons, leading to the emission of photoelectrons from various atoms, whose waves are then scattered by the surrounding atoms. The interference pattern between the scattered and direct photoelectron waves creates the photoelectron hologram, which may then be captured with an electron analyzer. Credit: Nano Letters

The search for techniques to electrically activate the dopant impurities in semiconductors with high efficiency and/or at high concentrations have always been an essential aspect of semiconductor device technology. However, despite various successful developments, the achievable maximum concentration of active dopants remains limited. Given the impact of the dopant atomic structures in this process, these structures had been previously investigated using both theoretical and experimental approaches. However, direct observation of the 3D structures of the dopant atomic arrangements had hitherto been difficult to achieve.

In this study, Kazuo Tsutsui at Tokyo Tech and colleagues involving researchers at JASRI, Osaka University, Nagoya Institute of Technology, and Nara Institute of Science and Technology developed spectro-photoelectron holography using SPring-8, and leveraged the capabilities of photoelectron holography in determining the concentrations of dopants at different sites, based on the peak intensities of the photoelectron spectrum, and classified electrically active / inactive atomic sites. These structures directly related with the density of carriers. In this approach, soft X-ray excitation of the core level electrons leads to the emission of photoelectrons from various atoms, whose waves are then scattered by the surrounding atoms. The resulting interference pattern creates the photoelectron hologram, which may then be captured with an electron analyzer. The photoelectron spectra acquired in this manner contain information from more than one atomic site. Therefore, peak fitting is performed to obtain the photoelectron hologram of individual atomic sites. The combination of this technique with first-principles simulations allows the successful estimation of the 3D structure of the dopant atoms, and the assessment of their different chemical bonding states. The method was used to estimate the 3D structures of arsenic atoms doped onto a silicon surface. The obtained results fully demonstrated the power of the proposed method and allowed confirmation of several previous results.

This work demonstrates the potential of spectro-photoelectron holography for the analysis of impurities in semiconductors. This technique allows analyses that are difficult to perform with conventional approaches and should therefore be useful in the development of improved doping techniques and, ultimately, in supporting the manufacture of high-performance devices.

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.

Tessera Technologies, Inc. (“Tessera”), a subsidiary of Xperi Corporation (the “Company”) (NASDAQ: XPER), today announced that it and certain of its affiliates entered into agreements with Broadcom Ltd. and certain of its affiliates (“Broadcom”), customers, and suppliers to settle and dismiss all pending litigation between them. In conjunction with the settlement, Broadcom entered into a new multi-year patent license agreement with Tessera.

“We are very pleased to have reached this settlement and license agreement with Broadcom,” said Jon Kirchner, CEO of Xperi Corporation. “This agreement validates the strength and breadth of our semiconductor portfolio, and provides us with a clear path to unlock the value of our innovations with other companies in the semiconductor industry.”

“The resolution of our dispute with Broadcom on mutually agreeable terms is a major milestone for Tessera’s IP licensing business. We look forward to a constructive relationship with Broadcom and thank the Broadcom team for their professional approach to reaching this resolution,” said Murali Dharan, president of Tessera.

The license agreement provides for an upfront payment in the fourth quarter of 2017 and recurring quarterly payments beginning in the first quarter of 2018. The other terms of the agreements are confidential.

Tessera and Invensas are subsidiaries of Xperi Corporation (NASDAQ: XPER). Over the past 27 years, research and development at both Tessera and Invensas has led to significant innovations in semiconductor packaging technology, which has been widely licensed and is found in billions of electronic devices globally.

Invensas, a wholly owned subsidiary of Xperi Corporation (“Xperi”) (NASDAQ:XPER), today announced the successful technology transfer of its Direct Bond Interconnect to Teledyne DALSA, a Teledyne Technologies company. This capability enables Teledyne DALSA to deliver next-generation MEMS and image sensor solutions that are more compact and higher performance to customers in the automotive, IoT and consumer electronics markets. Teledyne DALSA is a developer of high performance digital imaging and semiconductors and one of the world’s foremost pure-play MEMS foundries. Invensas and Teledyne DALSA announced the signing of a development license in February 2017.

“In partnership with Invensas, we have successfully completed the transfer of its revolutionary DBI technology to our manufacturing facilities in Bromont,” said Edwin Roks, president of Teledyne DALSA. “We are now ready to offer this enabling platform as part of our foundry services to customers, including our own business lines, seeking smaller, higher performance and more reliable MEMS and imaging solutions.”

“The manufacturing team at Teledyne DALSA has done a fantastic job bringing up our DBI process and is well-positioned to enable a new generation of high performance MEMS and image sensor solutions,” said Craig Mitchell, president of Invensas. “We are excited about the prospects for DBI to be integrated into a wide range of Teledyne DALSA’s branded products as well as those of their foundry customers.”

DBI technology is a low-temperature hybrid wafer bonding solution that allows wafers to be bonded with scalable fine pitch 3D electrical interconnect without requiring bond pressure. The technology is applicable to a wide range of semiconductor devices including MEMS, image sensors, RF front ends and stacked memory. DBI 3D interconnect can eliminate the need for through-silicon vias (TSVs) and reduce die size and cost while enabling pixel level interconnect for future generations of image sensors.

Leti, a research institute of CEA Tech, will demonstrate at CES 2018 its new wristband that measures physical indicators of a range of conditions, including sleep apnea, dehydration and dialysis-treatment response. 

APNEAband provides accurate, real-time detection of sleep-apnea events caused by pauses in breathing or shallow breaths during sleep. The wristband measures heart rate, variation in the time interval between heartbeats, oxygen saturation levels in the blood and stress level. The combination of these four indicators helps physicians make a complete and reliable medical diagnosis of sleep apnea.

“This small wristband eliminates the need to spend the night in a medical lab hooked up to sensors and equipment that measure these key indicators,” said Alexandre Thermet, Leti healthcare industrial partnership manager in the U.S. “APNEAband brings a safe, easy-to-use, affordable and non-invasive solution to detect sleep apnea at home.”

Working with Prof. Jean-Louis Pepin and his team at Grenoble Alpes University and INSERM from the Physiology Laboratory in Grenoble CHU’s hospital, Leti designed, developed and validated an advanced software technology that efficiently extracts and screens health parameters relevant to sleep apnea.  Pr. Pepin, a principal clinical-trial investigator at Grenoble CHU Hospital, and its team provided medical guidelines to support this sleep-apnea project.

APNEAband’s embedded technology can be applied to detect and track various other health conditions, such as acute mountain sickness, dehydration, dialysis treatment response, chronic pain, epileptic seizures, phobia and panic disorder. The wristband’s cardiac-coherence biofeedback also helps people who want to achieve total relaxation with simple breathing exercises. Possible applications also include detecting work-related stress or hot flashes and stress, while playing video games.

A new technique developed by researchers at Technische Universität München, Forschungszentrum Jülich, and RWTH Aachen University, published in Elsevier’s Materials Today, provides a unique insight into how the charging rate of lithium ion batteries can be a factor limiting their lifetime and safety.

State-of-the-art lithium ion batteries are powering a revolution in clean transport and high-end consumer electronics, but there is still plenty of scope for improving charging time. Currently, reducing charging time by increasing the charging current compromises battery lifetime and safety.

“The rate at which lithium ions can be reversibly intercalated into the graphite anode, just before lithium plating sets in, limits the charging current,” explains Johannes Wandt, PhD, of Technische Universität München (TUM).

Lithium ion batteries consist of a positively charged transition metal oxide cathode and a negatively charged graphite anode in a liquid electrolyte. During charging, lithium ions move from the cathode (deintercalate) to the anode (intercalate). However if the charging rate is too high, lithium ions deposit as a metallic layer on the surface of the anode rather than inserting themselves into the graphite. “This undesired lithium plating side reaction causes rapid cell degradation and poses a safety hazard,” Dr. Wandt added.

Dr. Wandt and Dr. Hubert A. Gasteiger, Chair of Technical Electrochemistry at TUM, along with colleagues from Forschungzentrum Jülich and RWTH Aachen University, set out to develop a new tool to detect the actual amount of lithium plating on a graphite anode in real-time. The result is a technique the researchers call operando electron paramagnetic resonance (EPR).

“The easiest way to observe lithium metal plating is by opening a cell at the end of its lifetime and checking visually by eye or microscope,” said Dr. Wandt. “There are also nondestructive electrochemical techniques that give information on whether lithium plating has occurred during battery charging.”

Neither approach, however, provides much if any information about the onset of lithium metal plating or the amount of lithium metal present during charging. EPR, by contrast, detects the magnetic moment associated with unpaired conduction electrons in metallic lithium with very high sensitivity and time resolution on the order of a few minutes or even seconds.

“In its present form, this technique is mainly limited to laboratory-scale cells, but there are a number of possible applications,” explains Dr. Josef Granwehr of Forschungzentrum Jülich and RWTH Aachen University. “So far, the development of advanced fast charging procedures has been based mainly on simulations but an analytical technique to experimentally validate these results has been missing. The technique will also be very interesting for testing battery materials and their influence on lithium metal plating. In particular, electrolyte additives that could suppress or reduce lithium metal plating.”

Dr. Wandt highlights that fast charging for electric vehicles could be a key application to benefit from further analysis of the work.

Until now, there has been no analytical technique available that can directly determine the maximum charging rate, which is a function of the state of charge, temperature, electrode geometry, and other factors, before lithium metal plating starts. The new technique could provide a much-needed experimental validation of frequently used computational models, as well as a means of investigating the effect of new battery materials and additives on lithium metal plating.

The researchers are now working with other collaborators to benchmark their experimental results against numerical simulations of the plating process in simple model systems.

“Our goal is to develop a toolset that facilitates a practical understanding of lithium metal plating for different battery designs and cycling protocols,” explains Dr. Rüdiger-A. Eichel of Forschungzentrum Jülich and RWTH Aachen University.

Accelerometers and gyroscopes are fueling the robotic revolution, especially the drones’ market segment. However, these MEMS devices are not the only ones on the market place anymore, with environmental sensors penetrating this industry too.

InvenSense, today TDK, combined it: the US-based company, IMU leader and formerly Apple’s supplier during many years, released last month the world’s 1st 7-axis motion tracking device combining accelerometer, gyroscope and pressure sensor. InvenSense announces the ICM-20789 7-axis combo sensor dedicated to mainly drones and flying toys as well as smart watches, wearables, activity monitoring, floor and stair counting etc.

The reverse costing company, System Plus Company has investigated the 7-axis component and technologies selected by InvenSense. Aim of this analysis was to identify the technologies selected by the leading company as well as to understand the impacts on the manufacturing costs.

What are the technical choices made by InvenSense? What are the benefits for the device in term of performances? What is the impact on the manufacturing process flow?

System Plus Consulting’s team proposes today a comprehensive technology and cost analysis, including as well a detailed comparison with the previous generation of combo sensors from InvenSense.

ILLUS_INVENSENSE_TDK_ReverseEngineering_SYSTEMPLUSCONSULTING_Dec2017

The drone’s market segment dedicated to consumer applications confirms its attractiveness with 23% CAGR between 2016 and 2021. According to Yole Développement, sister company of System Plus Consulting, the market should reach almost US$ 3.4 billion in 2023 (Source : Sensors for drones and robots: market opportunities and technology revolution report, Yole Développement, 2016). Under this dynamic context, System Plus Consulting’s experts are following the technical advances and the evolution of the manufacturing costs of the combo devices. InvenSense’s device is a good example of this technology breakthrough: indeed, for the 1st time, a company presents a 7-axis component combining accelerometer, gyroscope and barometric pressure sensor, integrated on the same package. Innovation clearly is not in the selection of the components, comments the reverse engineering & costing company, but more in the smart combination of the three devices in the same package.

Stéphane Elisabeth, RF and Advanced Packaging Cost Engineer from System Plus Consulting explains: “Using single package integration, the US company merged a 6-axis inertial sensor already identified in iPhone 6 with a barometric pressure sensor based on a design coming from the barometric division of Sensirion. Therefore, InvenSense took benefits of Sensirion’s partial acquisition, taking place in 2016, by developing a specific approach eliminating a package and minimizing board area requirements.”

ILLUS_INVENSENSE_TDK_Combo_CostBreakdown_SYSTEMPLUSCONSULTING_Dec2017

InvenSense was able to integrate its own barometric pressure sensor thanks to the knowledge reached with the acquisition of Sensirion’s barometric division. This device is shipped in a 4 mm x 4 mm x 1.37 mm land grid array (LGA) package.

InvenSense acquired the pressure sensor business from Sensirion Holding AG and its affiliates used in the development of capacitive-type monolithic digital pressure-sensor technology platform.

InvenSense’s financial report highlights the details of this acquisition: the purchase price associated with the acquisition was approximately US$9.8 million, of which US$5.7 million was allocated to developed technology with an estimated useful life of six years and US$4.1 million was allocated to goodwill.

Faced with this simple but impressive technical innovation, what will be the answer of other MEMS & Sensors manufacturers? Will this combination of IMU with barometric pressure sensor be followed by competitors? The selling prices of IMUs have fell in recent years and adding new functions is a way to keep a profitable ASP.