Category Archives: MEMS

A team at the University of California, Riverside Bourns College of Engineering has developed a novel way to build what many see as the next generation memory storage devices for portable electronic devices including smart phones, tablets, laptops and digital cameras.

The device is based on the principles of resistive memory, which can be used to create memory cells that are smaller, operate at a higher speed and offer more storage capacity than flash memory cells, the current industry standard. Terabytes, not gigbytes, will be the norm with resistive memory.

Read more: Crossbar unveils resistive RAM with simple, three-layer structure

The key advancement in the UC Riverside research is the creation of a zinc oxide nano-island on silicon. It eliminates the need for a second element called a selector device, which is often a diode.

"This is a significant step as the electronics industry is considering wide-scale adoption of resistive memory as an alternative for flash memory," said Jianlin Liu, a professor of electrical engineering at UC Riverside who is one of the authors of the paper. "It really simplifies the process and lowers the fabrication cost."

resistive RAM; nano island on silicon
This is a series of images that shows the zinc oxide nano-island on silicon and the three modes of the operation.

The findings were published online this week in the journal Scientific Reports, which is part of Nature Publishing Group. The paper is called "Multimode Resistive Switching in Single ZnO Nanoisland System."

Liu’s co-authors were: Jing Qi, a former visiting scholar in Liu’s lab and now an associate professor at Lanzhou University in China; Mario Olmedo, who earned his Ph.D. from UC Riverside and now works at Intel; and Jian-Guo Zheng, a director of the Laboratory of Electron and X-ray Instrumentation at UC Irvine.

Flash memory has been the standard in the electronics industry for decades. But, as flash continues to get smaller and users want higher storage capacity, it appears to reaching the end of its lifespan, Liu said.

With that in mind, resistive memory is receiving significant attention from academia and the electronics industry because it has a simple structure, high-density integration, fast operation and long endurance.

Researchers have also found that resistive memory can be scaled down in the sub 10-nanometer scale. Current flash memory devices are roughly using a feature size twice as large.

Resistive memory usually has a metal-oxide-metal structure in connection with a selector device. The UC Riverside team has demonstrated a novel alternative way by forming self-assembled zinc oxide nano-islands on silicon. Using a conductive atomic force microscope, the researchers observed three operation modes from the same device structure, essentially eliminating the need for a separate selector device.

Memory devices like disk drives, flash drives and RAM play an important role in our lives. They are an essential component of our computers, phones, electronic appliances and cars. Yet current memory devices have significant drawbacks: dynamic RAM memory has to be refreshed periodically, static RAM data is lost when the power is off, flash memory lacks speed, and all existing memory technologies are challenged when it comes to miniaturization.

Increasingly, memory devices are a bottleneck limiting performance. In order to achieve a substantial improvement in computation speed, scientists are racing to develop smaller and denser memory devices that operate with high speed and low power consumption.

Prof. Yossi Paltiel and research student Oren Ben-Dor at the Hebrew University of Jerusalem’s Harvey M. Krueger Family Center for Nanoscience and Nanotechnology, together with researchers from the Weizmann Institute of Science, have developed a simple magnetization progress that, by eliminating the need for permanent magnets in memory devices, opens the door to many technological applications.

Published in Nature Communications, the research paper, A chiral-based magnetic memory device without a permanent magnet, was written by Prof. Yossi Paltiel, Oren Ben Dor and Shira Yochelis at the Department of Applied Physics, Harvey M. Krueger Family Center for Nanoscience and Nanotechnology, Hebrew University of Jerusalem; and Shinto P. Mathew and Ron Naaman at the Department of Chemical Physics, Weizmann Institute of Science.

The research deals with the flow properties of electron charge carriers in memory devices. According to quantum mechanics, in addition to their electrical charge, electrons also have a degree of internal freedom called spin, which gives them their magnetic properties. The new technique, called magnetless spin memory (MSM), drives a current through chiral material (a kind of abundantly available organic molecule) and selectively transfers electrons to magnetize nano magnetic layers or nano particles. With this technique, the researchers showed it is possible to create a magnetic-based memory device that does not require a permanent magnet, and which could allow for the miniaturization of memory bits down to a single nanoparticle.

The potential benefits of magnetless spin memory are many. The technology has the potential to overcome the limitations of other magnetic-based memory technologies, and could make it possible to create inexpensive, high-density universal memory-on-chip devices that require much less power than existing technologies. Compatible with integrated circuit manufacturing techniques, it could allow for inexpensive, high-density universal memory-on-chip production.

According to the Hebrew University’s Prof. Paltiel, “Now that proof-of-concept devices have been designed and tested, magnetless spin memory has the potential to become the basis of a whole new generation of faster, smaller and less expensive memory technologies.”

The technology transfer companies of the Hebrew University (Yissum) and the Weizmann Institute of Science (Yeda) are working to promote the realization of this technology, by licensing its use and raising funds for further development and commercialization. With many possible applications, it has already attracted the attention of start-up funds.

The Hebrew University’s Center of Nanoscience and Nanotechnology helped with device fabrication and advice. Prof. Paltiel acknowledges the Yessumit internal grant from the Hebrew University, and Ron Naaman and Shinto P. Mathew acknowledge the support of the Minerva Foundation.

Established in 2001, the Center for Nanoscience and Nanotechnology deals with diverse fields of nanoscience such as new materials, molecular and nano-electronics, nano-electrooptics, nanomedicine and nano-biology. The research will enable technological development of new transistors, memory elements, sensors and biosensors, renewable energy sources, directed drug delivery schemes, and more. Operating within the Faculty of Science, the Center aims to create an enabling environment for interdisciplinary research, education, technological development and commercialization of scientific achievements in the field of Nanoscience and Nanotechnology, in order to participate as a leading force in the world nanotechnology revolution and contribute to Israeli academia, industry and society. The Center has almost 70 member groups and is expected to expand further through recruitment of promising young faculty members.

 

The Silicon Integration Initiative (Si2), a global semiconductor standards consortium, announced today that it has appointed John Ellis as vice president of Engineering and officer of Si2. He will be responsible for managing the technical strategy and direction for all semiconductor / EDA standardization projects created and managed at Si2. He will also directly manage Si2’s engineering staff to provide program management, training and documentation, software development, and infrastructure support.

John replaces Dr. Sumit DasGupta, who held the position since 2002 and retired on June 30th.

John has more than 25 years of experience leading diverse research and development programs spanning multiple industries. For over a decade, he served the semiconductor industry at SEMI, a global trade association for the semiconductor industry, where as VP of Technology he was responsible for semiconductor, photovoltaic, and flat-panel display manufacturing standards as well as coordination of industry initiatives such as e-Diagnostics and 450mm wafer size economic analyses. Prior to joining SEMI, John worked at Sandia National Labs on R&D projects for the Department of Energy, Department of Defense, National Institute of Standards and Technology, and other federal agencies. His broad experience includes nuclear weapons testing, missile guidance, air-borne and space-borne imaging systems, Internet and IC security, MEMS, and semiconductor manufacturing.

“John’s domain knowledge in semiconductor technology and software development, coupled with his extensive experience managing a large international staff to lead the development of important industry standards at SEMI, make him an excellent fit to lead engineering for Si2,” said Steve Schulz, President and CEO. “John received strong support from industry leaders on Si2’s Board of Directors, following many hours of rigorous interviewing and assessment. I look forward to John’s unique contributions in the months and years ahead that will further Si2’s mission and future success.”

Sono-Tek Corporation, a global ultrasonic spray technology company, announces a just completed expansion of their laboratory testing facility, located at their corporate headquarters in Milton, NY. The recent acquisition of new equipment, including an SEM microscope for on-site analysis of coatings performed in the lab, led to some reorganization and physical expansion of the facility itself, in order to provide a better workflow for customers and visitors, in addition to some increased elbow room.

sono-tek expands testing facility

The new equipment now installed, in particular the SEM microscope, enables Sono-Tek to gauge process variables by providing immediate on-site analysis of coatings requiring very precise deposition characteristics, such as photoresist onto MEMs, fuel cell coatings, medical implantable device coatings and other nanomaterial coatings. In addition, a new corona surface treatment has been installed, to better prepare substrates for improved surface tension characteristics prior to coating. Acquisition of at least one more surface treatment tool is planned as well.

Located in the heart of the Hudson Valley, Sono-Tek is pleased to help bring these high tech applications for precision semiconductor and advanced energy close to home.

"Access to equipment such as this new SEM is beneficial not only to Sono-Tek customers, but to the surrounding community of colleges and other research institutions in New York for advancing research and manufacturing of future innovations in our area," said Steve Harshbarger, Sono-Tek’s President. "We envision our lab continuing to grow in the coming years, as new applications for ultrasonic spray coating continue to develop."

 

Researchers at the Georgia Institute of Technology want to put your signature up in lights – tiny lights, that is. Using thousands of nanometer-scale wires, the researchers have developed a sensor device that converts mechanical pressure – from a signature or a fingerprint – directly into light signals that can be captured and processed optically.

The sensor device could provide an artificial sense of touch, offering sensitivity comparable to that of the human skin. Beyond collecting signatures and fingerprints, the technique could also be used in biological imaging and micro-electromechanical (MEMS) systems. Ultimately, it could provide a new approach for human-machine interfaces.

Read more: Driven by Apple and Samsung, light sensors achieve double-digit growth

"You can write with your pen and the sensor will optically detect what you write at high resolution and with a very fast response rate," said Zhong Lin Wang, Regents’ professor and Hightower Chair in the School of Materials Science and Engineering at Georgia Tech. "This is a new principle for imaging force that uses parallel detection and avoids many of the complications of existing pressure sensors."

piezo LED

Individual zinc oxide (ZnO) nanowires that are part of the device operate as tiny light emitting diodes (LEDS) when placed under strain from the mechanical pressure, allowing the device to provide detailed information about the amount of pressure being applied. Known as piezo-phototronics, the technology – first described by Wang in 2009 – provides a new way to capture information about pressure applied at very high resolution: up to 6,300 dots per inch. The research was scheduled to be reported August 11 in the journal Nature Photonics. It was sponsored by the U.S. Department of Energy’s Office of Basic Energy Sciences, the National Science Foundation, and the Knowledge Innovation Program of the Chinese Academy of Sciences.

 Piezoelectric materials generate a charge polarization when they are placed under strain. The piezo-phototronic devices rely on that physical principle to tune and control the charge transport and recombination by the polarization charges present at the ends of individual nanowires. Grown atop a gallium nitride (GaN) film, the nanowires create pixeled light emitters whose output varies with the pressure, creating an electroluminescent signal that can be integrated with on-chip photonics for data transmission, processing and recording.

"When you have a zinc oxide nanowire under strain, you create a piezoelectric charge at both ends which forms a piezoelectric potential," Wang explained. "The presence of the potential distorts the band structure in the wire, causing electrons to remain in the p-n junction longer and enhancing the efficiency of the LED."

The efficiency increase in the LED is proportional to the strain created. Differences in the amount of strain applied translate to differences in light emitted from the root where the nanowires contact the gallium nitride film.

Read more: Student develops brighter, smarter and more efficient LEDs

To fabricate the devices, a low-temperature chemical growth technique is used to create a patterned array of zinc oxide nanowires on a gallium nitride thin film substrate with the c-axis pointing upward. The interfaces between the nanowires and the gallium nitride film form the bottom surfaces of the nanowires. After infiltrating the space between nanowires with a PMMA thermoplastic, oxygen plasma is used to etch away the PMMA enough to expose the tops of the zinc oxide nanowires.

piezo LED 2

A nickel-gold electrode is then used to form ohmic contact with the bottom gallium-nitride film, and a transparent indium-tin oxide (ITO) film is deposited on the top of the array to serve as a common electrode. When pressure is applied to the device through handwriting, nanowires are compressed along their axial directions, creating a negative piezo-potential, while uncompressed nanowires have no potential. The researchers have pressed letters into the top of the device, which produces a corresponding light output from the bottom of the device. This output – which can all be read at the same time – can be processed and transmitted. The ability to see all of the emitters simultaneously allows the device to provide a quick response. "The response time is fast, and you can read a million pixels in a microsecond," said Wang. "When the light emission is created, it can be detected immediately with the optical fiber."

The nanowires stop emitting light when the pressure is relieved. Switching from one mode to the other takes 90 milliseconds or less, Wang said.

The researchers studied the stability and reproducibility of the sensor array by examining the light emitting intensity of the individual pixels under strain for 25 repetitive on-off cycles. They found that the output fluctuation was approximately five percent, much smaller than the overall level of the signal. The robustness of more than 20,000 pixels was studied.

A spatial resolution of 2.7 microns was recorded from the device samples tested so far. Wang believes the resolution could be improved by reducing the diameter of the nanowires – allowing more nanowires to be grown – and by using a high-temperature fabrication process.

Computer simulations have revealed how the electrical conductivity of many materials increases with a strong electrical field in a universal way. This development could have significant implications for practical systems in electrochemistry, biochemistry, electrical engineering and beyond.

The study, published in Nature Materials, investigated the electrical conductivity of a solid electrolyte, a system of positive and negative atoms on a crystal lattice. The behavior of this system is an indicator of the universal behavior occurring within a broad range of materials from pure water to conducting glasses and biological molecules.

Electrical conductivity, a measure of how strongly a given material conducts the flow of electric current, is generally understood in terms of Ohm’s law, which states that the conductivity is independent of the magnitude of an applied electric field, i.e. the voltage per metre.

This law is widely obeyed in weak applied fields, which means that most material samples can be ascribed a definite electrical resistance, measured in Ohms.

However, at strong electric fields, many materials show a departure from Ohm’s law, whereby the conductivity increases rapidly with increasing field. The reason for this is that new current-carrying charges within the material are liberated by the electric field, thus increasing the conductivity.

Remarkably, for a large class of materials, the form of the conductivity increase is universal – it doesn’t depend on the material involved, but instead is the same for a wide range of dissimilar materials.

The universality was first comprehended in 1934 by the future Nobel Laureate Lars Onsager, who derived a theory for the conductivity increase in electrolytes like acetic acid, where it is called the "second Wien effect." Onsager’s theory has recently been applied to a wide variety of systems, including biochemical conductors, glasses, ion-exchange membranes, semiconductors, solar cell materials and to "magnetic monopoles" in spin ice.

Researchers at the London Centre for Nanotechnology (LCN), the Max Plank Institute for Complex Systems in Dresden, Germany and the University of Lyon, France, succeeded for the first time in using computer simulations to look at the second Wien effect. The study, by Vojtech Kaiser, Steve Bramwell, Peter Holdsworth and Roderich Moessner, reveals new details of the universal effect that will help interpret a wide varierty of experiments.

Professor Steve Bramwell of the LCN said: "Onsager’s Wien effect is of practical importance and contains beautiful physics: with computer simulations we can finally explore and expose its secrets at the atomic scale.

"As modern science and technology increasingly explores high electric fields, the new details of high field conduction revealed by these simulations, will have increasing importance."

We hope you had a productive and enjoyable time at SEMICON West.  Despite the lackluster marketplace, this year’s SEMICON West achieved a 15 percent increase in unique visitors and over an 18 percent increase in R&D titles.  We were also happy to see such strong attendance at the keynotes, executive panels and TechXPOT stages, confirming our claim that SEMICON West delivers the most well-informed and influential speakers (and audience) in the industry.

Read more news from SEMICON West 2013

One of the strongest programs at SEMICON West 2013 was the materials program produced by the Chemical & Gases Manufacturer Group (CGMG), a SEMI special interest group.  This session, entitled, “Materials Growth Opportunities at Both Ends of the Spectrum” attracted over 450 people, more than any dedicated materials session we’ve ever had at SEMICON West.  And it’s no surprise. Innovations in materials are driving leading-edge semiconductor development.  Material markets are growing as the result of opportunities for both large geometry devices such as wide bandgap and printed electronics, and nano-scale devices at sub 22nm and beyond.

As much as materials took center stage at SEMICON West, the subject is simply too big and dynamic to cover in-depth at SEMICON West.  For the real “deep dive” into the critical trends and opportunities in advanced electronic materials, you must attend the SEMI Strategic Materials Conference (SMC), held October 16-17 at the Santa Clara Marriott in Silicon Valley, California.  SMC is the only executive conference in the world dedicated to advanced electronic materials.

SMC provides valuable forecasting information and serves as a forum for collaboration among all sectors of the advanced materials supply chain. This year’s program will feature powerhouse keynote speakers including:

 Luc Van den hove, president and CEO, imec

Gregg Bartlett, chief technology officer, GLOBALFOUNDRIES

Laurie E. Locascio, Ph.D., director, Material Measurement Laboratory, National Institute of Standards and Technology, and co-chair of the US government’s ambitious and essential Materials Genome Initiative

Other top-tier speakers will address market forecasts, materials developments in memory and logic, packaging materials trends, and materials-enabled “Beyond CMOS” devices.  Speakers will also address emerging materials opportunities and challenges in printed electronics, wide bandgap power devices, and MEMS.   The conference will also explore regulatory threats to the microelectronics industry and directly confront the increasingly difficult collaboration challenges between manufacturers, process equipment companies and diverse materials suppliers.

Last year’s conference sold out and attendees are encouraged to register early to ensure participation.

For additional information, please visit, http://www.semi.org/smc.

Thank you for making SEMICON West such a great success and hope to see you at the Strategic Materials Conference, if not before.

PI (Physik Instrumente) L.P., a manufacturer of nanopositioning equipment — offers the LPS-45 series of piezo positioning stages manufactured by PI subsidiary PI miCos.

This low profile linear translation stage is driven by a PIshift inertia-type piezo motor. The closed-loop stage is equipped with a high precision optical linear encoder providing for nanometer-level repeatability. An open-loop version and vacuum compatible and non-magnetic versions are also offered.

The PIShift piezo inertia drive is very quiet, due to its high operating frequency of 20 kHz. It provides high holding forces of 10 N. The drive principle works similar to the classic tablecloth trick, a cyclical alternation of static and sliding friction between a moving runner and the drive element.

When at rest, the maximum clamping force is available, with no holding current and consequently no heat generation.

PI provides a large variety of nanopositioning stages, based on several piezo-motor techniques, as well as classical electromagnetic drives.

Despite the very low profile of only 0.8” (20 mm) and compact dimensions, the stage offers a standard travel range of 30 mm (1.2”) and can be scaled up for longer travels, if needed.

PI’s precision linear translation stages are of great value for precision alignment in photonics, semiconductor, bio/nanotech applications as well as in scientific research.

Researchers at North Carolina State University have created a new flexible nano-scaffold for rechargeable lithium ion batteries that could help make cell phone and electric car batteries last longer.

The research, published in Advanced Materials ("Aligned Carbon Nanotube-Silicon Sheets: A Novel Nano-architecture for Flexible Lithium Ion Battery Electrodes"), shows the potential of manufactured sheets of aligned carbon nanotubes coated with silicon, a material with a much higher energy storage capacity than the graphite composites typically used in lithium ion batteries.

Read more: UC Riverside scientists discover new uses for carbon nanotubes

 “Putting silicon into batteries can produce a huge increase in capacity—10 times greater,” said Dr. Philip Bradford, assistant professor of textile engineering, chemistry and science at NC State. “But adding silicon can also create 10 times the problems.”

One significant challenge in using silicon is that it swells as lithium ion batteries discharge. As the batteries cycle, silicon can break off from the electrode and float around (known as pulverization) instead of staying in place, making batteries less stable.

When the silicon-coated carbon nanotubes were aligned in one direction like a layer of drinking straws laid end to end, the structure allowed for controlled expansion so that the silicon is less prone to pulverization, said Xiangwu Zhang, associate professor of textile engineering, chemistry and science at NC State.

 “There’s a huge demand for batteries for cell phones and electric vehicles, which need higher energy capacity for longer driving distances between charges,” Zhang said. “We believe this carbon nanotube scaffolding potentially has the ability to change the industry, although technical aspects will have to be worked out. The manufacturing process we’re using is scalable and could work well in commercial production.”

In 2012, the IC industry saw a two percent decline, but Yole Développement’s research reveals the MEMS sector managed another 10 percent growth to become an $11B business. Analysts expect a 12-13 percent CAGR through 2018 to create a $22.5B MEMS market, growing to 23.5 billion units. We have identified a number of changes as old MEMS products mature and new ones emerge. Cell phone demand drove strong growth for MEMS devices. Inertial sensor maker InvenSense continued to prove the worth of its fabless model with a ~30 percent increase in sales. Triquint saw 27 percent growth as its BAW filters won more slots in smartphones.

Yole Développement’s report shows markets for inkjet heads and DLPs have matured, but we see huge growth on the horizon for combination inertial sensors and for MEMS timing devices. Combination inertial sensors are starting to see high volume adoption in both consumer and automotive markets, and will quickly account for a signifi cant part of inertial sensor sales. Yole Développement’s report identifies new innovative MEMS devices that continue to emerge. Yole expect to see a number of them start production, though not reach significant volumes for a few years. MEMS autofocus could come to market shortly. Big smartphone players are now looking at adding environmental sensors for heat and humidity, and MEMS devices could win those slots.

Consumer is still the leading MEMS application with increasing needs for sensory interface. Yole Développement’s report ranks the top MEMS suppliers. In 2012, for the fi rst time, the top two MEMS suppliers on our annual Top 30 MEMS companies ranking are suppliers of inertial sensors, rather than of inkjet heads or micro-mirror actuators that have long dominated the sector. STMicroelectronics is the first company to grow a $1 billion MEMS business, surpassing Texas Instruments. The second sensor supplier, Robert Bosch, has also pushed ahead of Texas Instruments and Hewlett Packard for the first time. The expanding demand for MEMS in both smartphones and automotive applications is creating a rising group of players, that can expect to see solid sales in their future.

Yole Développement’s report shows how the results of MEMS players top 30 and companies with the largest growth clarify just how much the smartphone market is driving MEMS demand. AAC Technologies had strong sales of MEMS microphones that propelled them to 90 percent growth and $65 million in MEMS revenues, putting them in the Top 30 for the first time. More microphones in more phones also helped propel sales to grow more than 20 percent at both Infineon and Knowles. Yole Développement’s analysis shows that very few MEMS players have more than one device in production. Only big manufacturers such as STMicroelectronics or Robert Bosch have different devices in production.

Although there are many MEMS devices that have been in development for many years now (auto focus, micro fuel cells), Yole Développement’s analysis shows that crossing the gap from development to industrialization is still challenging. Consumer and mobile applications are the fastest growing areas for MEMS, having a strong impact on many developments happening at the moment. The report shows that pressure sensors started to be produced in large volumes for cell phone applications in 2012 and MEMS microphones are still growing, boosted by the integration of multiple microphones in smartphones. It is interesting to note the market for standalone accelerometers is decreasing as mobile devices increasingly use combo sensors. There is high demand for compact devices, partially offset by the growth of 6-axis e-compass for low-end smartphones. Adoption of 6-axis IMUs is now strong and 9-axis combos should follow within a few years. This push from the consumer side drives MEMS players to adopt new strategies.