State-of-the-Art Technology Flashes
Updates in silicon and electronics technology.
Ed.: This is a special feature courtesy of Binghamton University.
Bending an organic semiconductor boosts electrical flow. Organic transistors based on single crystals of rubrene can double the speed of electricity flowing through them when a crystal is slightly bent (strained). This behavior cannot be easily achieved with traditional semiconductors made of silicon. Rutgers University researchers found molecules of rubrene are arranged in a herringbone pattern (upper left in figure), forming highly ordered semiconducting molecular crystals that can be used to create rigid or flexible high-performance organic transistors, based on thick or ultra-thin single crystals, respectively. An example of a freestanding rubrene transistor is shown on a fingertip. This method could benefit next-generation electronics. (IEEC file #11946, NASA Tech Briefs, 10/1/20)
Organic transistors based on single crystals of rubrene
Fluoride materials for extra-thin computer chips. To make electronic components smaller, semiconductor two-dimensional (2-D) materials can be combined with new types of insulator materials. Smaller is the direction in which computer chips are moving. 2-D materials are considered to have great potential since they are as thin as a material can possibly be and, in extreme cases, only one single layer of atoms. This makes it possible to produce novel electronic components with tiny dimensions, high speed, and optimal efficiency. 2-D materials can only be used effectively if they can be combined with suitable material systems such as special insulating crystals. Researchers at the University of Vienna analyzed this problem and developed a transistor prototype with a calcium fluoride insulator. (IEEC file #11947, NASA Tech Briefs, 10/1/20)

Optical polymer waveguide backplane for high-performance computers has zero bit-error count. Optical communication technology can boost the speed of data transmission in many ways such as inter- and intra-datacenter and inter and intra-chip connections. An important part of this architecture is the computer backplane, which connects PCBs together to form a computer bus. Optical communication can greatly raise data transmission rates, helping to enable high-performance computers (HPCs). Researchers from Huazhong University have developed a high-speed, large-capacity, compact optical backplane based on optical polymer waveguides that use vertical-cavity surface-emitting lasers (VCSELs) emitting at 850nm for data transmission. The backplane network reaches 15Gb/s error-free data transmission via eight parallel channels; in the optical backplane, the 10 Gb/s in a channel is processed error-free by field-programmable gate-array chips. (IEEC file #11945, Laser Focus World, 10/13/20)

Memristor breakthrough: First single device to act like a neuron. Analog computing with neuron-like devices could efficiently solve problems traditional computers struggle with. One thing that’s kept copying the brain’s power efficiency is the lack of an electronic device that can act like a neuron. Hewlett Packard researchers have invented a device that meets those requirements. The most crucial part is the nanometers-thin niobium oxide (NbO2) layer that combines resistance, capacitance, and what’s called a Mott memristor. It’s predicted that if the possible device parameters were mapped, there would be regions of chaotic behavior between regions where behavior is stable. At the edge of some of these chaotic regions, devices can exist that do what the new artificial neuron does. (IEEC file #11950, IEEE Spectrum, 10/1/20)

Diagram of mott memristor
Carbon metal wires create path to carbon-based computers. Transistors based on carbon rather than silicon could potentially boost computing speed and cut power consumption more than thousandfold. University of California researchers have created the last tool in the toolbox, a metallic wire made entirely of carbon, setting the stage for a ramp-up in research to build carbon-based transistors and computers. This has been one of the key things missing in an all-carbon-based integrated circuit architecture. The team has worked for several years to make semiconductors and insulators from graphene nanoribbons, a structure composed entirely of carbon atoms arranged in an interconnected hexagonal pattern resembling chicken wire. (IEEC file #11949, Design Fax, 10/20/20)

Colorful perovskites: Thermochromic window technologies. Department of Energy NREL researchers report a breakthrough in developing a next-generation thermochromic window that not only reduces the need for air conditioning but simultaneously generates electricity. The technology, termed “thermochromic photovoltaic,” permits the window to change color to block glare and reduce unwanted solar heating when the glass gets warm on a hot, sunny day. This color change also leads to the formation of a functioning solar cell that generates on-board power. Thermochromic photovoltaic windows can help buildings turn into energy generators, increasing their contribution to the broader energy grid’s needs. The newest breakthrough now enables myriad colors and a broader range of temperatures that drive the color switch. This increases design flexibility for improving energy efficiency, as well as control over building aesthetics that is highly desirable for both architects and end users. (IEEC file #1196, Science Daily, 10/20/20)

New composite energizes the electric vehicle market. A new composite from Oak Ridge National Laboratory increases the electrical current capacity of copper wires, providing a new material that can be scaled to improve energy-efficiency in electric vehicles. With an improved performance, manufacturers have the ability to reduce volume and increase the power density in advanced motor systems. The material can be deployed in any component that uses copper, including bus bars and smaller connectors for electric vehicle traction inverters, as well as for applications such as wireless and wired charging systems. To produce lighter weight and great conductive properties, the team created lengths of composite copper-carbon nanotube materials, then deposited and aligned carbon nanotubes on flat copper substrates. (IEEC file #11924, NASA Tech Briefs, 9/29/20)

view of the material makeup of ultraconductive copper-carbon nanotube composite
Solar-powered smart dust. Industrial ubiquity of MEMS, increasing computing power of chips, the miniaturization of lab-on-a-chip devices, and increased connectivity, combined with the emergence of nanotechnologies, gave rise to the concept of smart dust, sub-millimeter-scale autonomous computing not larger than a grain of sand. An individual smart dust particle is a tiny sensor and computer, self-powered and wirelessly connected to a large network. Each particle can be left unattended and collects environmental data such as light, temperature, pressure, vibrations, the existence of toxins, etc. and transmits this data wirelessly. Smart dust can lead to autonomous artificial intelligent computation near the end-user, such as authentication, medical procedures, and healthcare monitoring, sensing, and tracking, industrial and supply chain monitoring, and defense applications. (IEEC file #11967, Nanowerk, 10/27/20)

High-pressure glass processing could reduce fiber-optic signal loss by 50%. Data transmission over optical fibers can be significantly improved by producing the silica (SiO2) glass fibers under high pressures, according to Penn State University researchers. They found that large voids form between silica atoms when the glass is heated and then cooled (quenched) under low pressure, but when this process occurs under 4 GPa, most of the large voids disappear, and the glass becomes a uniform lattice structure. Results show signal loss from silica glass fibers can be reduced by more than 50%, which could dramatically extend the distance data can be transmitted without the need for amplification. This would be a huge advance for the fiber-optic industry. (IEEC file #11968, Laser Focus World, 10/19/20)

Diagram illustrating nanoscale node
Light-driven quantum network promises faster, enhanced communication. Using magnetic and semiconducting materials, researchers at the University of Rochester and Cornell University designed a nanoscale node capable of using laser light to emit and accept photons to interact with other nodes. The development capitalizes on light’s physical properties to deliver a faster, increasingly efficient method to perform computations and detections. They arranged semiconductor and magnetic materials to form a platform that consisted of an array of pillars, each 120nm in height. The pillars mark the location of a distinct quantum state that can interact with photons and allow the photons to contact other locations across the device and with similarly constructed arrays at various locations. (IEEC file #11992, Photonics Media, 11/9/20)

Flexible self-charging battery under development. Strategic Elements is developing a self-charging battery technology through its collaboration with the University of New South Wales. The battery cells create electricity from humidity in the air or skin surface to self-charge themselves within minutes. No manual charging or wired power is required. Created with a printable ink, they are ideally suited for use in internet of things (IoT) devices. The battery ink is developed by integrating significant existing ink formulation and printed electronics intellectual property from the company’s Nanocube Memory Ink technology with an advanced graphene oxide material. Strong potential competitive advantages exist over lithium-based batteries that suffer from weight, safety and the need for constant power supply to recharge. (IEEC file #11969, Printed Electronics World, 10/19/20)

Bonding method attaches gallium nitride to thermally conductive materials. Georgia Institute of Technology researchers have developed an easier way to attach wide bandgap materials such as gallium nitride (GaN) to thermally conducting materials such as diamond. This would boost the cooling effect on GaN devices and lead to better performance through higher power levels, improved reliability, and lower manufacturing costs. The technique could have applications for wireless transmitters, radars, and other high-power and high-frequency electronic devices. The technique, called surface-activated bonding, uses an ion source in a high-vacuum to clean the surfaces of the GaN and diamond; it also activates the surfaces by creating dangling bonds. Introducing small amounts of silicon into the ion beams lets the process create strong atomic bonds at room temperature, direct bonding the GaN and single-crystal diamond to make a high-electron-mobility transistor (HEMT). (IEEC file #12008, Machine Design, 3/25/20)

Market Trends
VCSEL market to grow to $2.7 billion by 2025. The VCSEL market is expected to be worth $1 billion in 2020 and to show an 18.3% CAGR between 2020 and 2025 to reach $2.7 billion. While 3-D applications for mobile and consumer are still booming, automotive, medical and AR/VR applications are emerging. Mobile 3-D sensing will represent around 75% of overall VCSEL revenues in 2020. In the VCSEL market, telecom and infrastructure applications, mainly datacom, are expected to reach $516 million in 2025, a CAGR of 13.2%. Other applications are not significant yet but could emerge in the mid- to long-term, such as automotive applications like LiDAR or driver monitoring systems. (IEEC file #11941, Electronics Weekly, 10/12/20)

Researchers develop graphene-based Covid-19 sensor. Caltech researchers have designed a new sensor that can enable at-home diagnosis of Covid-19 infection. With the coronavirus disease a highly contagious disease transmissible even by people who do not display symptoms, subsequently responding to people infected with it is both challenging and time critical. Rapid testing kits cut down on the time needed to assess whether someone carries the coronavirus, with or without symptoms. The team designed a multiplex testing method and incorporates a low-cost sensor that can diagnose Covid-19 in 10 minutes or less. (IEEC file #11937, Science Times, 10/2/20)

Flexible electronics are the future in wearable health monitoring. In a new research report, analysts find significant opportunities for flexible electronics to be applied to healthcare. They forecast the market for healthcare products containing flexible electronics to be worth over $8.3 billion by the year 2030. A significant market trend is toward decentralized healthcare and utilizing technologies to monitor and care for people remotely. During the Covid-19 pandemic, healthcare systems around the world rapidly deployed remote care services in the form of telehealth. Such efforts often need to be supported by devices in the home capable of providing medical-grade data. But ultimately, monitoring efforts rely on the correct use of the devices. (IEEC file #1196, Medical Design Briefs, 10/2/20)

LG’s rollable OLED-R TV. If you happen to live in South Korea and have $87,000, LG has a rollable OLED TV for you. LG has been demonstrating its rollable display technology since 2014. At CES 2019, this technology was sufficiently mature for commercial launch. The LG Signature OLED R is the world’s first rollable TV and will be made available at “several premium consumer electronics stores” located across South Korea. The 65″ screen can be rolled up into its brushed aluminum casing. (IEEC file #11957, PC Mag, 10/20/20)

LG's rollable OLED-R TV on display
Advanced packaging market to have steady growth of 8% to $40 billion by 2026. The advanced packaging market is set to grow from its current market value of $25+ billion to over $40 billion by 2026. Advanced packaging was developed to improve the performance of a device and simultaneously shrink the packages. It is termed as a general grouping of a variety of different techniques such as system-in-package, 3D-IC, 2.5D, and fan-out wafer-level packaging. Semiconductor packaging materials are known to be a class of electronic solutions utilized to form the connection of IC chip to the packaging substrate. The advanced packaging market is bifurcated in terms of packaging type, application, and regional landscape. With respect to packaging type, the advanced packaging market is classified into 2.5D/3-D, fan-out, embedded-die, fan-in WLP and flip-chip. The fan-in WLP segment will witness considerable growth. (IEEC file #11954, Semiconductor Digest,10/9/20)

Implantable sensor could measure bodily functions and then safely biodegrade. Penn State University researchers have designed a highly sensitive flexible gas sensor that can be implanted in the body and safely biodegrade into materials that are absorbed by the body. The flexible and implantable sensor monitors various forms of nitric oxide (NO) and nitrogen dioxide (NO2) gas in the body. The team added a twist to their sensor design by making it from materials that are not just implantable, flexible and stretchable, but also biodegradable. The researchers say future work could look at designing integrated systems that could monitor other bodily functions for healthy aging and various disease applications. (IEEC file #12000, Science Daily, 11/10/20)

Recent Patents
Liquid cooling through conductive interconnect (assignee: Intel Corp.) pub. no. 16/379619. Embodiments include semiconductor packages and cooling semiconductor packaging systems. A semiconductor package includes a second die on a package substrate, first dies on the second die, conductive bumps between the first dies and the second die, a cold plate and a manifold over the first dies, second die, and package substrate, and first openings in the manifold. The first openings are fluidly coupled through the conductive bumps. The semiconductor package may include a first fluid path through the first openings of the manifold, where a first fluid flows through the first fluid path.

Flexible printed circuit to mitigate cracking at through-holes (assignee: CommScope) patent no. 10,798,819. Flexible fingers for flexible printed circuits improve the crack resistance of prior art designs. The crack resistance can be improved by encapsulating the trace inside additional layers such that the outer two layers include only the lands of the through-hole, and all other copper is etched away. The crack resistance can also be improved by strategically adding copper on layers other than the trace layer, including attaching it to the land of the through-hole as a stub. These two designs can be combined to include a stub trace into a four-layered design.

Method for 3-D integrated wiring structure and semiconductor structure (assignee: Yangtze Memory Tech.) pub. no. US10796993. Embodiments of methods and structures for forming a 3-D integrated wiring structure are disclosed. The method can include forming an insulating layer on a front side of a first substrate; forming a semiconductor layer on a front side of the insulating layer; patterning the semiconductor layer to expose at least a portion of a surface of the insulating layer; forming a plurality of semiconductor structures over the front side of the first substrate, wherein the semiconductor structures include a plurality of conductive contacts and a first conductive layer; joining a second substrate with the semiconductor structures; performing a thinning process on a backside of the first substrate to expose the insulating layer and one end of the plurality of conductive contacts.

Active package substrate having anisotropic conductive layer (assignee: Intel Corp.) patent no. 10,790,257. Semiconductor packages, including active package substrates, are described. In an example, the active package substrate includes an active die between a top substrate layer and a bottom substrate layer. The top substrate layer may include a via, and the active die may include a die pad. An anisotropic conductive layer may be disposed between the via and the die pad to conduct electrical current unidirectionally between the via and the die pad. In an embodiment, the active die is a flash memory controller, and a memory die is mounted on the top substrate layer and placed in electrical communication with the flash memory controller through the anisotropic conductive layer.

Gary Miller
is technology analyst at IEEC, Binghamton University. He has over 40 years’ experience in electronic packaging. He previously was the chief mechanical engineer at Lockheed Martin;
Integrated Electronics Engineering Center (IEEC)
is a New York Center of Advanced Technology (CAT) responsible for the advancement of electronics packaging. Its mission is to provide research into electronics packaging to enhance partners’ products, improve reliability and understand why parts fail. More information is available at