Tag Archives: Katherine Bourzac

IBM and a 5 nanometre chip

If this continues, they’re going to have change the scale from nano to pico. IBM has announced work on a 5 nanometre (5nm) chip in a June 5, 2017 news item on Nanotechnology Now,

IBM (NYSE: IBM), its Research Alliance partners GLOBALFOUNDRIES and Samsung, and equipment suppliers have developed an industry-first process to build silicon nanosheet transistors that will enable 5 nanometer (nm) chips. The details of the process will be presented at the 2017 Symposia on VLSI Technology and Circuits conference in Kyoto, Japan. In less than two years since developing a 7nm test node chip with 20 billion transistors, scientists have paved the way for 30 billion switches on a fingernail-sized chip.

A June 5, 2017 IBM news release, which originated the news item, spells out some of the details about IBM’s latest breakthrough,

The resulting increase in performance will help accelerate cognitive computing [emphasis mine], the Internet of Things (IoT), and other data-intensive applications delivered in the cloud. The power savings could also mean that the batteries in smartphones and other mobile products could last two to three times longer than today’s devices, before needing to be charged.

Scientists working as part of the IBM-led Research Alliance at the SUNY Polytechnic Institute Colleges of Nanoscale Science and Engineering’s NanoTech Complex in Albany, NY achieved the breakthrough by using stacks of silicon nanosheets as the device structure of the transistor, instead of the standard FinFET architecture, which is the blueprint for the semiconductor industry up through 7nm node technology.

“For business and society to meet the demands of cognitive and cloud computing in the coming years, advancement in semiconductor technology is essential,” said Arvind Krishna, senior vice president, Hybrid Cloud, and director, IBM Research. “That’s why IBM aggressively pursues new and different architectures and materials that push the limits of this industry, and brings them to market in technologies like mainframes and our cognitive systems.”

The silicon nanosheet transistor demonstration, as detailed in the Research Alliance paper Stacked Nanosheet Gate-All-Around Transistor to Enable Scaling Beyond FinFET, and published by VLSI, proves that 5nm chips are possible, more powerful, and not too far off in the future.

Compared to the leading edge 10nm technology available in the market, a nanosheet-based 5nm technology can deliver 40 percent performance enhancement at fixed power, or 75 percent power savings at matched performance. This improvement enables a significant boost to meeting the future demands of artificial intelligence (AI) systems, virtual reality and mobile devices.

Building a New Switch

“This announcement is the latest example of the world-class research that continues to emerge from our groundbreaking public-private partnership in New York,” said Gary Patton, CTO and Head of Worldwide R&D at GLOBALFOUNDRIES. “As we make progress toward commercializing 7nm in 2018 at our Fab 8 manufacturing facility, we are actively pursuing next-generation technologies at 5nm and beyond to maintain technology leadership and enable our customers to produce a smaller, faster, and more cost efficient generation of semiconductors.”

IBM Research has explored nanosheet semiconductor technology for more than 10 years. This work is the first in the industry to demonstrate the feasibility to design and fabricate stacked nanosheet devices with electrical properties superior to FinFET architecture.

This same Extreme Ultraviolet (EUV) lithography approach used to produce the 7nm test node and its 20 billion transistors was applied to the nanosheet transistor architecture. Using EUV lithography, the width of the nanosheets can be adjusted continuously, all within a single manufacturing process or chip design. This adjustability permits the fine-tuning of performance and power for specific circuits – something not possible with today’s FinFET transistor architecture production, which is limited by its current-carrying fin height. Therefore, while FinFET chips can scale to 5nm, simply reducing the amount of space between fins does not provide increased current flow for additional performance.

“Today’s announcement continues the public-private model collaboration with IBM that is energizing SUNY-Polytechnic’s, Albany’s, and New York State’s leadership and innovation in developing next generation technologies,” said Dr. Bahgat Sammakia, Interim President, SUNY Polytechnic Institute. “We believe that enabling the first 5nm transistor is a significant milestone for the entire semiconductor industry as we continue to push beyond the limitations of our current capabilities. SUNY Poly’s partnership with IBM and Empire State Development is a perfect example of how Industry, Government and Academia can successfully collaborate and have a broad and positive impact on society.”

Part of IBM’s $3 billion, five-year investment in chip R&D (announced in 2014), the proof of nanosheet architecture scaling to a 5nm node continues IBM’s legacy of historic contributions to silicon and semiconductor innovation. They include the invention or first implementation of the single cell DRAM, the Dennard Scaling Laws, chemically amplified photoresists, copper interconnect wiring, Silicon on Insulator, strained engineering, multi core microprocessors, immersion lithography, high speed SiGe, High-k gate dielectrics, embedded DRAM, 3D chip stacking and Air gap insulators.

I last wrote about IBM and computer chips in a July 15, 2015 posting regarding their 7nm chip. You may want to scroll down approximately 55% of the way where I note research from MIT (Massachusetts Institute of Technology) about metal nanoparticles with unexpected properties possibly having an impact on nanoelectronics.

Getting back to IBM, they have produced a slick video about their 5nm chip breakthrough,

Meanwhile, Katherine Bourzac provides technical detail in a June 5, 2017 posting on the Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website), Note: A link has been removed,

Researchers at IBM believe the future of the transistor is in stacked nanosheets. …

Today’s state-of-the-art transistor is the finFET, named for the fin-like ridges of current-carrying silicon that project from the chip’s surface. The silicon fins are surrounded on their three exposed sides by a structure called the gate. The gate switches the flow of current on, and prevents electrons from leaking out when the transistor is off. This design is expected to last from this year’s bleeding-edge process technology, the “10-nanometer” node, through the next node, 7 nanometers. But any smaller, and these transistors will become difficult to switch off: electrons will leak out, even with the three-sided gates.

So the semiconductor industry has been working on alternatives for the upcoming 5 nanometer node. One popular idea is to use lateral silicon nanowires that are completely surrounded by the gate, preventing electron leaks and saving power. This design is called “gate all around.” IBM’s new design is a variation on this. In their test chips, each transistor is made up of three stacked horizontal sheets of silicon, each only a few nanometers thick and completely surrounded by a gate.

Why a sheet instead of a wire? Huiming Bu, director of silicon integration and devices at IBM, says nanosheets can bring back one of the benefits of pre-finFET, planar designs. Designers used to be able to vary the width of a transistor to prioritize fast operations or energy efficiency. Varying the amount of silicon in a finFET transistor is not practicable because it would mean making some fins taller and other shorter. Fins must all be the same height due to manufacturing constraints, says Bu.

IBM’s nanosheets can range from 8 to 50 nanometers in width. “Wider gives you better performance but takes more power, smaller width relaxes performance but reduces power use,” says Bu. This will allow circuit designers to pick and choose what they need, whether they are making a power efficient mobile chip processor or designing a bank of SRAM memory. “We are bringing flexibility back to the designers,” he says.

The test chips have 30 billion transistors. …

It was a struggle trying to edit Bourzac’s posting with its good detail and clear writing. I encourage you to read it (June 5, 2017 posting) in its entirety.

As for where this drive downwards to the ‘ever smaller’ is going, there’s Dexter’s Johnson’s June 29, 2017 posting about another IBM team’s research on his Nanoclast blog on the IEEE website (Note: Links have been removed),

There have been increasing signs coming from the research community that carbon nanotubes are beginning to step up to the challenge of offering a real alternative to silicon-based complementary metal-oxide semiconductor (CMOS) transistors.

Now, researchers at IBM Thomas J. Watson Research Center have advanced carbon nanotube-based transistors another step toward meeting the demands of the International Technology Roadmap for Semiconductors (ITRS) for the next decade. The IBM researchers have fabricated a p-channel transistor based on carbon nanotubes that takes up less than half the space of leading silicon technologies while operating at a lower voltage.

In research described in the journal Science, the IBM scientists used a carbon nanotube p-channel to reduce the transistor footprint; their transistor contains all components to 40 square nanometers [emphasis mine], an ITRS roadmap benchmark for ten years out.

One of the keys to being able to reduce the transistor to such a small size is the use of the carbon nanotube as the channel in place of silicon. The nanotube is only 1 nanometer thick. Such thinness offers a significant advantage in electrostatics, so that it’s possible to reduce the device gate length to 10 nanometers without seeing the device performance adversely affected by short-channel effects. An additional benefit of the nanotubes is that the electrons travel much faster, which contributes to a higher level of device performance.

Happy reading!

A rose by any other name: water pinning nanostructures and wettability

There are two items about rose petals as bioinspiration for research in this posting. The first being the most recent research where scientists in Singapore have made an ultrathin film modeled on rose petals. From an Aug. 13, 2014 news item on Nanowerk (Note: A link has been removed),

A*STAR [based in Singapore] researchers have used nanoimprinting methods to make patterned polymeric films with surface topography inspired by that of a rose petal, producing a range of transparent films with high water pinning forces (“Bioinspired Ultrahigh Water Pinning Nanostructures”).

An Aug. 13, 2014 A*STAR news highlight, which originated the news item, describes the nature of the research,

A surface to which a water droplet adheres, even when it is turned upside down, is described as having strong water pinning characteristics. A rose petal and a lotus leaf are both superhydrophobic, yet dissimilarities in their water pinning properties cause a water droplet to stick to a rose petal but roll off a lotus leaf. The two leaf types differ in their micro- and nanoscale surface topography and it is these topographical details that alter the water pinning force. The rose petal has almost uniformly distributed, conical-shaped microscale protrusions with nanoscale folds on these protrusions, while the lotus leaf has randomly distributed microscale protrusions.

The imprinted surfaces developed by Jaslyn Law and colleagues at the A*STAR Institute of Materials Research and Engineering and the Singapore University of Technology and Design have uniformly distributed patterns of nanoscale protrusions that are either conical or parabolic in shape. The researchers found that the water pinning forces on these continuously patterned surfaces were much greater than on non-patterned surfaces and surfaces composed of isolated nanopillared structures or nanoscale gratings. They could then achieve high water pinning forces by patterning the nanoprotrusions onto polymeric films with a range of different non-patterned hydrophobicities, including polycarbonate, poly(methyl methacrylate) and polydimethylsiloxane (see image).

“Other methods that recreate the water pinning effect have used actual rose petals as the mold, but unless special care is taken, there are likely to be defects and inconsistencies in the recreated pattern,” says co-author Andrew Ng. “While bottom-up approaches for making patterns — for example, laser ablation, liquid flame spray or chemical vapor deposition — are more consistent, these methods are limited in the types of patterns that can be used and the scale at which a substrate can be patterned.”

In contrast, nanoimprinting methods are capable of fabricating versatile and large-scale surfaces, and can be combined with roll-to-roll techniques, hence potentially enabling more commercial applications.

The patterned polycarbonate surfaces were also shown to reduce the ‘coffee-ring’ effect: the unevenly deposited film left behind upon the evaporation of a solute-laden droplet. This mitigation of the coffee-ring effect may assist microfluidic technologies and, more generally, the patterned surfaces could be used in arid regions for dew collection or in anti-drip applications such as in greenhouses.

The study which was published online in Dec. 2013, was featured in a Jan. 22, 2014 article by Katherine Bourzac for C&EN (Chemistry and Engineering News),

In the early morning, dew clings to rose petals; when the sun rises, the dewdrops act like tiny lenses, making diffraction patterns that attract pollinating insects, says Jaslyn Bee Khuan Law, a materials scientist at the Agency for Science, Technology, and Research (A*STAR), in Singapore. A drop of water will cling to a rose petal even when it’s tilted or held upside down. The petals can hold onto these droplets because their surfaces consist of closely packed conical structures a few micrometers across. These microscale surface patterns tweak the surface tension of the water droplets, causing them to cling to the petals.

But none of these fabrication methods are amenable to large-scale, low-cost manufacturing, preventing commercialization of the water-clinging surfaces. So Law turned to a specialty of her lab: nanoimprint lithography. This printing method utilizes metal or silicon drums molded with nanoscale features on their surfaces. When the molds are heated and pressed against sheets of plastic, the plastic is embossed with the nanoscale pattern. This roll-to-roll printing process resembles the way newspapers are printed. It’s capable of producing large-area films in a short amount of time.

Water droplets easily slid off plastic films patterned with simple nanoscale gratings; isolated nanoscale pillars hung onto water slightly better. But the films with the best properties consisted of tightly packed cones about 300 nm tall. Plastic patterned with these structures could hold onto water droplets as massive as 69 mg. The team could print a 110- by 65-mm sheet of this plastic film at a speed of 10 m per minute. Currently, the dimensions of the films are limited by the size of the premade molds, Law says.

While the Singapore group has made good progress on manufacturing these materials, very basic, vexing questions about how water clings to these surfaces remain, Hayes says. For example, very small changes in the surface’s roughness can switch it from water-pinning to super hydrophobic, and researchers don’t have a detailed understanding of why.

Here’s a link to and a citation for the paper,

Bioinspired Ultrahigh Water Pinning Nanostructures by Jaslyn Bee Khuan Law, Andrew Ming Hua Ng, Ai Yu He, and Hong Yee Low. Langmuir, 2014, 30 (1), pp 325–331 DOI: 10.1021/la4034996 Publication Date (Web): December 20, 2013
Copyright © 2013 American Chemical Society

This paper appears to be open access (I was able to access it by clicking on the HTML option).

Finally, here’s an image supplied by the A*Star researchers to illustrate their work,

[downloaded from http://pubs.acs.org/doi/full/10.1021/la4034996]

[downloaded from http://pubs.acs.org/doi/full/10.1021/la4034996]

This second rose petal item comes from Australia and dates from Fall 2013. From a Sept. 18, 2013 news item on ScienceDaily,

A new nanostructured material with applications that could include reducing condensation in airplane cabins and enabling certain medical tests without the need for high tech laboratories has been developed by researchers at the University of Sydney [Australia].

“The newly discovered material uses raspberry particles — so-called because of their appearance — which can trap tiny water droplets and prevent them from rolling off surfaces, even when that surface is turned upside down,” said Dr Andrew Telford from the University’s School of Chemistry and lead author of the research recently published in the journal, Chemistry of Materials.

The ability to immobilise [pin] very small droplets on a surface is, according to Dr Telford, a significant achievement with innumerable potential applications.

A Sept. 17, 2013 University of Sydney news release, which originated the news item, provides more insight into the research where the scientists have focused on ‘raspberry particles’ which could also be described as the ‘conical structures’ mentioned in the A*STAR work to achieve what appear to be similar ends,

Raspberry particles mimic the surface structure of some rose petals.

“Water droplets bead up in a spherical shape on top of rose petals,” Dr Telford said. “This is a sign the flower is highly water repellent.”

The reasons for this are complex and largely due to the special structure of the rose petal’s surface. The research team replicated the rose petal by assembling raspberry particles in the lab using spherical micro- and nanoparticles.

The result is that water droplets bead up when placed on films of the raspberry particles and they’re not able to drip down from it, even when turned upside down.

“Raspberry particle films can be described as sticky tape for water droplets,” Dr Telford said.

This could be useful in preventing condensation issues in airplane cabins. It could also help rapidly process simple medical tests on free-standing droplets, with the potential for very high turnover of tests with inexpensive equipment and in remote areas.

Other exciting applications are under study: if we use this nanotechnology to control how a surface is structured we can influence how it will interact with water.

“This means we will be able to design a surface that does whatever you need it to do.

“We could also design a surface that stays dry forever, never needs cleaning or able to repel bacteria or even prevent mould and fungi growth.

“We could then tweak the same structure by changing its composition so it forces water to spread very quickly.

“This could be used on quick-dry walls and roofs which would also help to cool down houses.

“This can only be achieved with a very clear understanding of the science behind the chemical properties and construction of the surface,” he said.

The discovery is also potentially viable commercially.

“Our team’s discovery is the first that allows for the preparation of raspberry particles on an industrial scale and we are now in a position where we can prepare large quantities of these particles without the need to build special plants or equipment,” Dr Telford said.

Here’s a link to and a citation for the Australian paper,

Mimicking the Wettability of the Rose Petal using Self-assembly of Waterborne Polymer Particles by A. M. Telford, B. S. Hawkett, C. Such, and C. Neto. Chem. Mater., 2013, 25 (17), pp 3472–3479 DOI: 10.1021/cm4016386 Publication Date (Web): July 23, 2013
Copyright © 2013 American Chemical Society

This paper is behind a paywall.

Seeing things from a bug’s perspective—a new type of digital camera

The new digital cameras exploit large arrays of tiny focusing lenses and miniaturized detectors in hemispherical layouts, just like eyes found in arthropods

The new digital cameras exploit large arrays of tiny focusing lenses and miniaturized detectors in hemispherical layouts, just like eyes found in arthropods

A May 1, 2013 news item on Nanowerk provides some details about a new ‘bug-eyed’ digital camera,

An interdisciplinary team of researchers has created the first digital cameras with designs that mimic those of ocular systems found in dragonflies, bees, praying mantises and other insects. This class of technology offers exceptionally wide-angle fields of view, with low aberrations, high acuity to motion, and nearly infinite depth of field.

Taking cues from Mother Nature, the cameras exploit large arrays of tiny focusing lenses and miniaturized detectors in hemispherical layouts, just like eyes found in arthropods. The devices combine soft, rubbery optics with high performance silicon electronics and detectors, using ideas first established in research on skin and brain monitoring systems by John A. Rogers, a Swanlund Chair Professor at the University of Illinois at Urbana-Champaign, and his collaborators.

The May 1, 2013 University of Illinois news release by John Kubetz, which originated the news item, describes the special properties of an insect eye and how the camera mimics those properties,

Eyes in arthropods use compound designs, in which arrays of smaller eyes act together to provide image perception. Each small eye, known as an ommatidium, consists of a corneal lens, a crystalline cone, and a light sensitive organ at the base. The entire system is configured to provide exceptional properties in imaging, many of which lie beyond the reach of existing man-made cameras.

The researchers developed new ideas in materials and fabrication strategies allowing construction of artificial ommatidia in large, interconnected arrays in hemispherical layouts. Building such systems represents a daunting task, as all established camera technologies rely on bulk glass lenses and detectors constructed on the planar surfaces of silicon wafers which cannot be bent or flexed, much less formed into a hemispherical shape.

“A critical feature of our fly’s eye cameras is that they incorporate integrated microlenses, photodetectors, and electronics on hemispherically curved surfaces,” said Jianliang Xiao, an assistant professor of mechanical engineering at University of Colorado Boulder and coauthor of the study. “To realize this outcome, we used soft, rubbery optics bonded to detectors/electronics in mesh layouts that can be stretched and deformed, reversibly and without damage.”

On a more technical note, from the news release,

The fabrication starts with electronics, detectors and lens arrays formed on flat surfaces using advanced techniques adapted from the semiconductor industry, said Xiao [Jianliang Xiao, an assistant professor of mechanical engineering at University of Colorado Boulder and coauthor of the study], who began working on the project as a postdoctoral researcher in Rogers’ lab at Illinois. The lens sheet—made from a polymer material similar to a contact lens—and the electronics/detectors are then aligned and bonded together. Pneumatic pressure deforms the resulting system into the desired hemispherical shape, in a process much like blowing up a balloon, but with precision engineering control.

The individual electronic detectors and microlenses are coupled together to avoid any relative motion during this deformation process. Here, the spaces between these artificial ommatidia can stretch to allow transformation in geometry from planar to hemispherical. The electrical interconnections are thin, and narrow, in filamentary serpentine shapes; they deform as tiny springs during the stretching process.

According to the researchers, each microlens produces a small image of an object with a form dictated by the parameters of the lens and the viewing angle. An individual detector responds only if a portion of the image formed by the associated microlens overlaps the active area. The detectors stimulated in this way produce a sampled image of the object that can then be reconstructed using models of the optics.

Katherine Bourzac in her May 1, 2013 article for Nature magazine provides some additional insight and a perspective (intentional wordplay) from a researcher who has an idea of how he might like to integrate this new type of camera into his own work,

Insect eyes are made up of hundreds or even thousands of light-sensing structures called ommatidia. Each contains a lens and a cone that funnels light to a photosensitive organ. The long, thin ommatidia are bunched together to form the hemispherical eye, with each ommatidium pointing in a slightly different direction. This structure gives bugs a wide field of view, with objects in the periphery just as clear as those in the centre of the visual field, and high motion sensitivity. It also allows a large depth of field — objects are in focus whether they’re nearby or at a distance.

“The whole thing [the new digital camera] is stretchy and thin, and we blow it up like a balloon” so that it curves like a compound eye, says Rogers. The current prototype produces black-and-white images only, but Rogers says a colour version could be made with the same design.

With the basic designs in place, Rogers says, his team can now increase the resolution of the camera by incorporating more ommatidia. “We’d like to do a dragonfly, with 20,000 ommatidia,” he says, which will require some miniaturization of the components.

Alexander Borst, who builds miniature flying robots at the Max Planck Institute of Neurobiology in Martinsried, Germany, says that he is eager to integrate the camera into his machines. Insects’ wide field of vision helps them to monitor and stabilize their position during flight; robots with artificial compound eyes might be better fliers, he says.

For interested parties, here’s a link to and a citation for the research paper,

Digital cameras with designs inspired by the arthropod eye by Young Min Song, Yizhu Xie, Viktor Malyarchuk, Jianliang Xiao, Inhwa Jung, Ki-Joong Choi, Zhuangjian Liu, Hyunsung Park, Chaofeng Lu, Rak-Hwan Kim, Rui Li, Kenneth B. Crozier, Yonggang Huang, & John A. Rogers.
Nature 497, 95–99 (02 May 2013) doi:10.1038/nature12083 Published online 01 May 2013

This article is behind a paywall.

I last mentioned John A. Rogers and the University of Illinois in a Feb. 28, 2013 posting about a bendable, stretchable lithium-ion battery.