Nanoelectronics December 2013/January 2014 Viewpoints
2013: The Year in Review
Several developments occurred during 2013 that could have a lasting effect on the field of nanoelectronics, with certain segments of the industry undergoing transitional phases that could have the power to determine the long-term future of a variety of technologies. For example, the replacement of indium tin oxide (ITO) as a transparent conducting film in touch-screen applications is an issue that will have massive implications for materials such as metallic nanowires, carbon nanotubes (CNTs), and graphene—all of which are competing for control of the market. Just as important in a commercial sense is the pursuit of a successor technology to flash and NAND memory. Several candidates are vying for dominance in this market, and 2013 saw developments in a variety of data-storage technologies. Numerous scientific, commercial, and business developments also occurred in the display, flexible electronics, and materials industries during 2013. For example, quantum-dot (QD) films, in both image display and capture, reached commercial maturity, while massive injections of funding into graphene research reaffirmed the potential future importance of this material. These developments will continue into 2014, which will see the introduction of new materials, processes, and technologies to the marketplace.
QDs—semiconducting nanoparticles—made a significant contribution to driving forward the field of nanoelectronics in 2013. In addition to having longer-term applications such as quantum computing and photovoltaics, QDs are having a more immediate effect on the display industry. Following 2012's announcement from Nanosys and 3M detailing their work on QD films that enhance the performance of LCDs, the technology recently reached commercial markets in the form of Amazon's new tablet device (the Kindle Fire HDX 7). Massachusetts firm QD Vision also revealed its collaboration with Sony, working on very similar materials, which they term "ColorIQ," for the Bravia range of televisions. This technology won Gold for QD Vision in the Component of the Year category at the Society for Information Display conference in Vancouver, Canada, in 2013. Technologies such as this one could pose a serious threat to the commercial success of OLED screens in the lucrative television market.
In addition to its use in image display, QD technology could also find use in capturing images. Developers at California firm InVisage are applying QDs to enhance CCD image sensors for mobile-phone cameras—enabling the use of thinner lenses and, in turn, thinner devices in general. In 2013, the firm announced the injection of $20 million of Series D funding in order to commercialize its proprietary technology. Working in partnership with Nokia Growth Partners, InVisage anticipates that its sensors will reach commercial markets in the second quarter of 2014—a move that, if successful, could completely disrupt the mobile-phone-camera market in the coming two to five years.
Other materials generating interest for most major players in the display industry are metal oxides and low-temperature polysilicon, which can find use as thin-film transistors (TFTs) and have the potential ultimately to replace the current standard backplane material: amorphous silicon. The extent to which amorphous silicon dominates the market means that wholesale replacement will not occur immediately. However, the limitations of amorphous silicon (in terms of resolution and refresh rates and carrier mobility) mean that in the next few years, manufacturers will be looking to alternatives. Metal-oxide TFTs offer high-quality image reproduction and low power consumption, and—crucially—implementation of the technology does not require high capital expenditure. Sony and Panasonic both exhibited 56-inch 4K OLED TVs that use metal-oxide backplanes in 2013, and other major players such as Samsung, Sharp, LG, and Toshiba are all developing similar technologies. California firm Applied Materials, one of the global leaders in metal-oxide TFT technology—in terms of both materials and large-scale fabrication—introduced new products in 2013 that enable its customers to fabricate higher-quality structures on larger substrates than previously achievable. Another California firm, CBRITE, received over $5.5 million of Series D funding in 2013 to support the commercialization of its metal-oxide TFT technology. CBRITE claims that its materials "have nano-structures which are many orders of magnitude smaller than the TFT channel width, resulting in inherent pixel-to-pixel uniformity over a large area."
Transparent Conductive Films
ITO is the current standard material in use as a transparent conductive film in electronics applications, and it finds use in the majority of touch-screen devices. However, indium is in short supply, and relatively volatile prices are driving electronics manufacturers to find cheaper, more abundant, and higher-performance alternatives. CNT technology, for example, is a potential contender in the race to dominate the transparent-conductive-film market. Finnish firm Canatu is pioneering the development and commercialization of thin films of CNTs and carbon nanobuds (CNBs), launching in October 2013 its Generation 5 product family of CNB-based transparent conductive films. These films possess properties that compare very favorably with both ITO and metallic nanowire-based systems and enable the development of flexible and three-dimensional touch-enabled electronics devices. Canatu's technology is ready for electronics manufacturers looking to integrate carbon-based transparent conductive films. And, indeed, 2013 saw the commercial debut of the material in certain high-performance smartphones and notebooks.
Metallic nanoparticle and nanowire inks are another alternative to ITO. These materials represent a significant advance on rigid and brittle transparent-conducting oxides, enabling flexible applications fabricated using roll-to-roll printing procedures. In 2013, California firm Cambrios developed silver-nanowire structures, selling the materials and technology to companies such as LG, eTurboTouch, and CNinnovations for use in touch-screen devices. These companies all exhibited mobile-phone prototypes using Cambrios technology at trade conferences in early 2013. Also in 2013, DuPont introduced a new series of metallic (most likely copper-based) nanoparticle inks with the specific intention of offsetting increasingly volatile silver prices. DuPont claims that its new ink can reduce manufacturing costs for printed electronics firms by up to 20%. Other firms working on the commercialization of copper nanoparticle inks include Showa Denko and NovaCentrix.
Data storage—largely enabled by nanomaterials—represents one of the most important sectors of the electronics industry. Most major industrial players, as well as a variety of academic groups and research institutes, are undertaking research into the preparation of higher-density and more efficient memory devices. Following Everspin's 2012 announcement that it was testing its first spin-transfer-torque (STT) MRAM device, Samsung also aimed to advance its interest in the technology in 2013—inviting submissions for novel ideas, the most promising of which will receive funding for a period of three years. This initiative forms part of the Samsung Global MRAM Innovation (SGMI) program and highlights the extent to which Samsung views the future importance of the technology. The overarching goal of the SGMI program is to build connections with leading groups in the research community that will aid Samsung in the commercialization of STT-MRAM. Despite heavy interest in STT-MRAM from major players such as Samsung and Toshiba, as well as other specialists (including Avalanche, Crocus, and Spin Transfer Technologies), Everspin remained the sole firm that was shipping significant volumes of MRAM chips in 2013—primarily for niche applications. For example, in 2013, Buffalo Memory used Everspin's STT-MRAM chips in its solid-state-drive cards—the first STT-MRAM product on the market. However, Everspin faces competition from other firms such as Crocus Technology. Crocus is developing an alternative data-storage device based on thermally assisted toggle MRAM technology and announced in November 2013 the launch of the first production line at its Moscow, Russia, plant.
Massachusetts firm Nantero uses CNTs to develop next-generation semiconductor components and, in particular, Nano-RAM (NRAM) memory chips—another potential contender vying to dominate the competitive data-storage market. NRAM devices possess several advantages—including low power consumption, fast write speeds, and high thermal stability. Nantero sources its CNTs from Brewer Science, which in 2013 announced the installation of a new reactor that will increase the production of its CNTRENE C100 family of electronics-grade CNTs by a factor of ten. This move was a direct response to projected market demand for Nantero's NRAM devices.
Another competing technology—phase-change memory, or PRAM—made slower advances in 2013. Early 2013 saw Idaho firm Micron commence the mass production of next-generation PRAM units for the mobile-phone market. The 45-nanometer device—half the size of the previous structure—represents a significant improvement on other products using the same technology. However, no other major advances in this field occurred in 2013, and Samsung remained the only other serious player with interest in this technology.
The other major contender to replace DRAM and NAND flash memory—HP's memristor devices—suffered a slight setback in 2013 when the firm's CTO announced that it may not become commercially available for another five years. In terms of data-storage density, the technology is impressive, but slower speeds than DRAM (although faster than flash) may prove to be a turnoff for consumers who increasingly demand faster and more efficient devices.
Thermal-Energy Management and Thermoelectrics
One of the most pressing issues currently facing the electronics community is efficient heat dissipation—with all major players investigating means by which to manage excess thermal energy in electronics systems. Many nanomaterials are at the heart of these techniques. For example, the NanoHex consortium—an €8.3 million European Commission (EC) project that finished in 2013—studied the use of ceramic nanofluids with enhanced thermal conductivity to transport heat away from electronics components efficiently. Siemens, a leading member of the consortium, plans to apply this technology in the cooling systems of power-electronics modules in use in high-speed trains.
IBM is another major player aiming to improve the heat-dissipation properties of electronics chips. A 2013 conversation with Dr. Bruno Michel, leader of IBM's Advanced Thermal Packaging division, revealed that IBM recently discontinued its efforts to produce high-thermal-conductivity nanofluids for electronics-cooling applications. Despite the achievable high thermal conductivities, the concomitant increase in viscosity reduces the efficiency of these fluids. IBM is, however, currently researching other nanomaterials and methods that could enable the efficient cooling of electronics components and devices. One such approach involves injecting nanoparticle-filled liquids into stacked chips—forming high-thermal-conductivity bridges when the solvent evaporates and enabling excess thermal energy to dissipate more rapidly. IBM hopes to start exploring high-volume manufacturing of this approach in 2014, with a view to testing commercial products in 2016.
In early 2013, Laird Technologies—a major thermoelectrics company—acquired US thin-film-thermoelectric company Nextreme (which also sells Peltier cooling devices for advanced chip-cooling applications) after having previously collaborated on design and distribution. In terms of technological developments, 2013 saw Fujifilm Corp develop and exhibit a polymeric thermoelectric-conversion material. Fujifilm claims that the material—which it developed in collaboration with Japan's National Institute of Advanced Industrial Science and Technology—is "the organic thermoelectric material showing the highest thermoelectric conversion efficiency" and that the printable device can generate several milliwatts of power with a temperature difference of only 1°C.
Materials science is continually driving advances in the field of nanoelectronics. Several developments during 2013 could have a strong influence on the potential impact of certain specific materials. For example, many analysts believe that graphene will one day play an important role in a variety of electronics applications. The year 2013 saw some significant steps on the road to the likely commercialization of graphene-enabled electronics devices. One such step was the announcement that the EC would be investing €500 million into graphene research in the next ten years—a figure that academic and industrial partners will match. This grant essentially makes graphene research the EC's flagship science program and is an explicit endorsement of a material that has resulted in no major commercial products—conducting inks from firms like Vorbeck aside. This situation could be set to change, with touch-screen applications likely to reach Asian markets in 2014. In addition to seeing this surge in funding, 2013 also saw an increase in graphene-based industrial activity. Several companies (notably XG Sciences, Angstron Materials, Applied Graphene Materials, and Vorbeck) are increasing production capabilities, and major players such as Phillips, Nokia, IBM, and—especially—Samsung are currently participating in a patent "gold rush"—with a view to utilizing the material in electronic and optical devices.
CNTs—essentially a cylindrical form of graphene—also enable several nanoelectronics applications. Despite the fact that some firms, such as Brewer Science, expanded their production capacity in 2013, CNTs suffered a major blow when Bayer MaterialScience announced that it would no longer be researching or manufacturing the material. The firm stated in a press release that "It has been found that the potential areas of application that once seemed promising from a technical standpoint are currently either very fragmented or have few overlaps with the company's core products and their application spectrum." A single company's ceasing to manufacture CNTs does not by any means indicate that the material does not have a future in the electronics industry. However, the fact that Bayer MaterialScience could not envisage turning a profit from its CNT research is a blow to proponents of the technology—especially given that only a few years ago the firm filed an application to expand its annual production capacity from 260 to 3000 tonnes. The move indicates that some firms overestimated the overall impact that CNTs would have in the short to medium term and highlights the fact that the commercialization of new and much-hyped materials is not always straightforward—a point that large companies looking to apply graphene in devices should take note of.
Look for These Developments in 2014
- Some of the first products that integrate graphene into electronic devices are likely to appear on the market in 2014. Initially the material will replace the ITO layer in touch-screen devices—an application for which several other competing technologies exist.
- The intense interest in graphene will drive research into other advanced two-dimensional materials such as boron nitride, molybdenum disulfide, and silicene in 2014. However, commercial applications are unlikely to appear for at least five to ten years.
- Flexible-electronics applications, on both plastic and paper substrates, are likely to appear, at least in prototype form, in 2014, first in Asian markets and then in markets in other developed nations. Metallic nanoparticle inks and advances in nanofabrication techniques will enable these applications.
- Although 2014 is possibly too early for textile-integrated electronics to reach a commercial market, the technology is sufficiently mature for military and health-related applications to become a distinct possibility.
- Sensors containing QDs—pioneered by InVisage—could find use in commercially available mobile-phone cameras in 2014, enabling thinner and lighter devices.
- Canatu will open a high-volume-manufacturing plant in 2014—enabling larger-scale production of its proprietary CNB technology for touch-screen applications.
- Given the extent of industry interest and taking 2012 and 2013 developments into account, 2014 is likely to see further commercial developments for STT-MRAM data-storage technology.
- Crocus Technology envisages that by the end of 2014 it will be capable of producing 2000 thermally assisted toggle MRAM wafers per month.
- Adoption of metal-oxide TFTs by major electronics players will continue in 2014, resulting in the technology's becoming an increasingly standard component for flat-panel displays.