Research: 2016 year in review
DNA could bring new innovations to microelectronics
Recent advances in research being conducted by Leti and INAC scientists under CEA project A3DN could help overcome one of the major technological hurdles facing microelectronics R&D.
So, what does DNA have to do with microelectronics? DNA strings measure around a nanometer—as do the pattern geometries the researchers are working on. And DNA’s base-pairing capacities can ensure more accurate pattern alignment than the most powerful microelectronics technologies currently available.
Pattern alignment—between active circuit components or levels—has to be perfect for the electronic signals to be transmitted. The smaller the geometries, the more difficult it is to align the patterns.
Cost-competitive custom designs.
In other good news, DNA strings can be used to create custom designs at very competitive costs. The Leti and INAC researchers working on the A3DN project made suspended conductive nanowires from metal-coated DNA fragments. The nanowires could be used in NEMS. The researchers also deposited high-density nanometric origami-like DNA structures (period values less than 15 nm) onto a substrate, and then transferred the patterns using traditional lithography. These very encouraging research results could open up a wide range of opportunities in nanoelectronics, micro and nanosystems, biochemistry, nanocharacterization, and more.
Could sugar make treating liver disease easier?
Wilson’s disease, a genetic disorder that causes copper to build up in the liver, is treated using chelating agents to remove the metal. Research conducted by INAC, BIG*, and DCM** looked at two chelating agents that could ultimately offer improved penetration into liver cells.
The chelating agents were functionalized with N-Acetylgalactosamine, a sugar that interacts specifically with liver cell membranes’ biological receptors. Penetration is improved as the number of units of the sugar is increased. For example, with three to four units per molecule, the optimal value, efficiency was 1,000 to 10,000 times better than with a single unit.
The researchers are now working on further improving liver-cell targeting. At the level currently attained, the chelating agent’s affinity for the biological receptor is close to that of proteins used in vivo.
Wireless pacemaker could be just over the horizon
Grenoble’s TIMA lab and a consortium of partners are working on a project backed by the ANR, France’s national research agency, to develop a wireless pacemaker. TIMA’s energy-harvesting system, which is built on a multilayer piezoelectric blade, has already brought in some excellent results, operating in a simulated environment for 109 cycles (which corresponds to around three years of use), delivering the 10 microwatts required to run a miniature wireless pacemaker.
The energy-harvesting system would be activated by the heart muscle’s mechanical activity and would be integrated directly into the pacemaker unit (20 mm long and 6 mm in diameter) implanted inside the right ventricle. Currently, traditional wired pacemakers are powered by a battery implanted near the collarbone, requiring surgery to change the battery approximately every eight years.
Power conversion: GaN components show promise
The aeronautics and automotive industries are looking for more compact, efficient power converters. Leti’s latest research on a converter built on gallium-nitride-on-silicon components is producing some results sure to please these demanding industries. When tested on a demonstrator system, the converters displayed low losses and high switching speeds enabling frequencies up to 30 MHz. The best converters currently available are limited to 100 kHz.
GaN components are also bidirectional, which means that they can switch on alternating current without the need for a conversion stage, eliminating a number of passive elements. The components are also compatible with CMOS technology, which offers low fabrication costs. Leti will test a new batch of the converters that just came out of the institute’s clean rooms on a demonstrator system in the first half of 2017.
Testing antibiotic efficacy in just one hour
MIT used Leti’s suspended micro-resonators to develop a new microchip for fast drug testing. The chip measures cell culture growth by weighing the culture with accuracy to within a femtogram. The measurement provides an indication of the culture’s response to a drug such as an antibiotic. The results of the research were published in Nature Biotechnology.
The test takes just one hour; traditional techniques take an entire day. And, over longer timespans, the microchip can also be used to assess the efficacy of anti-cancer drugs.
Leti took advantage of this new project with MIT to make further improvements to process yields; the institute recently delivered another 800 of the micro-resonators to MIT. The technology is now robust enough for industrial scale-up.
MRIs could become more accurate and affordable
Researchers from Leti and G2Elab are working to develop a new kind of medical imaging technology, “fast field-cycling MRI” (FFC-MRI). The research is being conducted under the four-year EU IDentIFY project, which kicked off in 2016. The new MRI is expected to be both more accurate and affordable than current technologies.
The concept was developed at the University of Aberdeen, where a prototype was used to demonstrate the technology’s capacity to detect cancer, characterize pre-cancerous areas, and monitor diseased tissues’ response to treatment. FFC-MRI could also be used for the early diagnoses of neurodegenerative diseases like Alzheimer’s and Parkinson’s.
Controlling magnetic fields remains a major challenge
For the technology to one day be brought to patients, researchers will have to come up with a way to control the magnetic fields used—which range from a substantial 0.2 Tesla to levels well under the Earth’s magnetic field. With these very low magnetic fields, the slightest external disruption can modify the field, rendering the measurements taken inaccurate. What is more, the magnetic fields must be stable within a volume equivalent to a 30-cm-diameter sphere.
G2Elab and Leti will develop measurement and active compensation systems to counter disruptions to the magnetic field: G2ELab will focus on magnetic field modelling and measurement, while Leti will develop the correction spools and associated electronic components. A first project milestone is expected to be reached by the end of 2016.
LMGP takes atomic layer deposition to the next level
At the end of September LMGP presented its new SALD (Spatial Atomic Layer Deposition) reactor to MINATEC. It is the first reactor of its kind in France. It operates at atmospheric pressure, bringing down costs, and can perform atomic layer deposition up to 100 times faster than traditional ALD equipment.
And the resulting layers are both very thin—from a few to a few hundred nanometers—and homogeneous, characteristics that take the lab equipment one step closer to where it needs to be for industrial-scale use.
The new reactor is well-suited for encapsulating systems and for interface engineering (anti-corrosion protection, barrier materials, etc.). INES (France’s solar-energy research organization) is using the reactor to deposit electrode materials onto solar cells under the Institut Carnot Energies du futur project.
Driverless vehicles: it’s all about the algorithms
The main obstacle to developing tomorrow’s 100% driverless vehicles is the huge processing power required. Today, you would have to virtually fill the vehicles with powerful computers to run them! For the past three years, researchers at Leti have been working on a breakthrough technology to replace today’s algorithms, originally developed for robotics applications, with new algorithms developed specifically for driverless vehicles.
The new algorithms can fuse and interpret data from three different sensor technologies in under 50 milliseconds, using a new, more parsimonious mathematics that slashes processing requirements a hundred fold. The algorithms are protected by two patents and garnered lots of interest when they were presented at DAC 2016 in Texas in June. They will also be presented at the European Forum in Brussels on October 15, and at the Vision trade show in Stuttgart in November.
Nanocomputers: skyrmions now within reach
Researchers at Spintec have achieved skyrmions that are stable at ambient temperature and without a magnetic field. The researchers deposited a magnetic layer of cobalt several atoms thick between a layer of platinum and a layer of magnesium oxide. The resulting structure significantly increases the magnetic interaction that underpins the skyrmion’s helicoidal structure.
The skyrmion—a quasiparticle measuring just a few nanometers—is the holy grail of researchers in search of very-low-energy memory solutions. However, to date, very low temperatures or strong magnetic fields have been required to observe skyrmions. Spintec is now a step closer to overcoming this hurdle using a cobalt deposition technique already commonly used in the microelectronics industry.
Nanoresonators: the plot thickens amid new insights
A team of researchers from Leti along with three of Leti’s international partners* have fi nally shed new light on the discrepancy of up to two orders of magnitude between the theoretical detection limits of nanoresonators and the resonators’ actual performance. Until now, it was believed that the tiniest mass or force that could be detected by a nanoresonator depended on temperature fl uctuations in the resonator’s environment. Given that state-of-the-art resonators off er sensitivities of 10-21 gram, the theory was plausible. In research published in Nature Nanotechnology, a Grenoble-based team of researchers demonstrated that the nanoresonator’s own frequency plays a much greater role than environmental factors. In other words, the “background noise” once thought to be the main culprit of performance problems is actually not as signifi cant as the noise from the system itself. One resonator, two frequencies The researchers developed and patented a technique that simultaneously exposes the nanoresonator to two frequencies close to the system’s resonant frequency. They then used the return signal to determine the infl uence of measurement noise and that of fl uctuations in the resonant frequency. While the research did provide new insights into the discrepancies between theoretical and actual detection limits, there is still much to uncover. The researchers tested the various theories in the literature—temperature gaps, trapped charge, diff usion of gas molecules on the resonator’s vibrating cantilever—to no avail. They still don’t know why the resonant frequency fl uctuates. Leti is pursuing its investigations, hoping to solve the mystery and unlock the secrets to better nanoresonator performance.
Leti and Liten join forces on additive technologies
Researchers at Leti are convinced that additive technologies are a plus for silicon! And research carried out with Liten proves that they are right. Additive technologies can be used for very thick (100 microns and more) layers and for large-surface systems at lower cost than silicon processes. The researchers have already produced a radio-frequency inductor using screen printing. The inductor, which operates at 2 GHz with a quality factor of 30, has already garnered interest from a manufacturer for integration.
The researchers have also built an energy-harvesting system demonstrator. Rather than the usual hybrid piezoelectric layer, the system boasts a piezoelectric layer printed using a process developed by Liten. The system provides enough energy to power a radio-frequency link.
Lithography: non-chemically-amplified resin validated
In the coming years, non-chemically-amplified resins could be used in 300 mm lithography processes to create circuit patterns with more accurate control of dimensions and lower edge roughness. The members of the industrial R&D project Imagine, which include Leti, recently validated the process on industrial-grade equipment for the first time ever.
A preliminary evaluation of the resin was completed with a single beam. The resin was then successfully tested on a 1,300-beam Mapper machine (Mapper is also a partner on the project). The process was developed specifically to facilitate transfer to a manufacturer, which is expected to take place in 2018.
In other research conducted under an Inter-Carnot project currently undergoing final approvals, Leti plans to assess other non-chemically-amplified resins in conjunction with the University of Mulhouse.
Nanosystems design: Samson growing in popularity
The Inria-Nano-D team developing the Samson generic nanosystems design software package, which has been working out of MINATEC for more than a year now, has a number of new wins to report. In March the team secured a European Research Council Proof of Concept grant to assess the software’s market potential, and recently released version 0.5 of the tool. In June, the team is running its first Samson School in Aix-les-Bains.
Samson is used to analyze and design nanosystems of all types, and offers interactive simulation features. The software boasts an open architecture, which enables users to create and share modules—a key advantage over costly and non-customizable commercial software. The beta version, released in March 2015, has more than 600 academic and private-sector users worldwide.
2016–2020: FMNT expands
The FMNT (Federation for Micro and Nanotechnologies) saw its mandate renewed for an additional five years on January 1, 2016. The organization took advantage of the occasion to bring in three new labs, bringing its total headcount to nearly 500—a 30% increase. The FMNT is now one of France’s largest research organizations in the fields of microelectronics and nanotechnology. Until end-2015, the FMNT encompassed four labs: LTM, LMGP, IMEP-LaHC, and part of G2ELab’s activities. The new, expanded FMNT is now home to Spintec, two research teams from TIMA, and an additional team from LCIS in Valence.
Five strategic research areas and seven labs
The expanded FMNT is headed by Mireille Mouis (IMEP-LaHC) and will focus on five strategic research areas—microelectronics, telecommunications components and systems, integrated measurement systems, materials and components for energy, and components and systems for healthcare—that show just how much the FMNT’s scope has broadened over the past several years. The organization’s seven labs will work to better leverage synergies, ramp up transversal research topics, and submit joint proposals for EU projects. FMNT had already begun pursuing these goals in certain research areas during its last five-year mandate and will now use this approach on a much larger scale. A new platform, Opera, will be set up as a single point of contact for outside researchers seeking to use the functional characterization equipment. Finally, FMNT will overhaul its website in order to raise its online profile.
A biobattery with built-in energy recovery
A biobattery capable of producing energy from ocean and lake sediments would be a wonderful invention! But for it to become a reality, scientists first have to figure out how to extract in real time a source of energy whose characteristics vary on a scale of one to ten depending on the environment. Leti has risen to this challenge with a new interface circuit that enables biobatteries to harvest tens of microwatts, potentially providing a continuous source of power for distributed sensors—temperature, salinity, oxygen, CO2—used to monitor aquatic ecosystems. The researchers are now working on the biobatteries’ long-term reliability, and plan to conduct tests in a lake near Grenoble.
Telecommunications: III–V/silicon tunable laser
Solid indium phosphide (INP) tunable lasers for telecommunications networks are costly to manufacture and ill-suited to integration with other photonic and electronic components. Researchers from Leti and the III–V Lab have now produced a tunable laser on a silicon substrate coupled with a III–V material.
This hybrid monomode laser boasts a novel waveguide system coupled with two thermo-optically-controlled rings for a tuning range of 35 nm. The system, which enables the allocation of 80 wavelengths in the International Telecommunications Union (ITU) standard wavelength plan, is intended for metropolitan and long-distance telecommunications networks.
The researchers are now working on integrating the hybrid lasers with other optical functions with the goal of producing complete transmitters suitable for telecommunications and data centers.