Stress-free path to stress-free metallic films paves the way for next-gen circuitry

Nanowerk  July 4, 2021 To create thin films of tungsten with unprecedentedly low levels of film stress researchers in Japan have been working with scattering (HiPIMS), a sputtering technique. Using argon gas and a tungsten target, the team looked at how ions with different energies arrived at the substrate over time in unprecedented detail. Instead of using a bias pulse set off at the same time as the HiPIMS pulse, they used their knowledge of when different ions arrived and introduced a tiny delay, 60 microseconds, to precisely select for the arrival of high energy metal ions. They found that […]

Graphene “nano-origami” creates tiniest microchips yet

EurekAlert  February 15, 2021 An international team of researchers (UK, Greece, USA – Rice University, Italy) identified and investigated different geometries of line defects in graphene and molybdenum disulfide such as standing collapsed wrinkles, folded wrinkles, and grain boundaries that exhibit distinct strain and doping. They determined the influence of the defects on local stiffness. For wrinkles of similar height, the stiffness of graphene was found to be higher than that of molybdenum disulfide by 10–15% due to stronger in-plane covalent bonding. Defects in graphene predominantly show compressive strain and increased carrier density. Defects in molybdenum disulfide predominantly show tensile […]

Extremely energy efficient microprocessor developed using superconductors

EurekAlert  December 28, 2020 Using the adiabatic quantum-flux-parametron (AQFP), as a building block researchers in Japan have developed and demonstrated a prototype 4-bit AQFP microprocessor called MANA (Monolithic Adiabatic iNtegration Architecture). The AQFP is capable of data processing and data storage, it can operate up to a clock frequency of 2.5 GHz making this on par with today’s computing technologies. They expect this to increase to 5-10 GHz as they make improvements in design methodology and experimental setup. According to the researchers even when taking this cooling overhead into account, the AQFP is still about 80 times more energy-efficient when […]

An LED that can be integrated directly into computer chips

MIT News  December 14, 2020 LEDs can be used as proximity sensors in smartphones, distance measurement in autofocus cameras, and gesture recognizers. As they are difficult to make from silicon, the LED sensors must be manufactured separately from their device’s silicon-based processing chip making them prohibitively expensive. Researchers at MIT have designed a silicon-based LED with specially engineered junctions to enhance brightness. The LED operates at low voltage, but it still produces enough light to transmit a signal through 5 meters of fiber optic cable. They envision a day when LED technology can be built right onto a device’s silicon […]

Toward imperceptible electronics that you cannot see or feel

Phys.org  December 14, 2020 Transparent electronics—such as head-up displays that allow pilots to read flight data while keeping their eyes ahead of them. For healthcare applications the electronics should be sufficiently flexible to conform to skin. Although silver nanowire networks meet these criteria, the current methods of development create random nanowire alignment that is insufficient for advanced applications. Researchers in Japan used high-resolution printing to fabricate centimeter-scale cross-aligned silver nanowire arrays, with reproducible feature sizes from 20 to 250 micrometers. The microelectrodes-based organic field-effect transistors exhibited excellent multi-functionality. The sheets were well-suited for transparent electronics. As a proof-of-concept for functionality, […]

Electronic components join forces to take up 10 times less space on computer chips

Science Daily  August 10, 2020 An international team of researchers (USA – University of Illinois, China) used specialized etching and lithography process to pattern 2D circuitry onto very thin membranes joining the capacitors, inductors, with signal lines, all in a single plane. Then rolled into a thin tube and placed onto a chip. The circuitry can be tuned to achieve the needed electrical interactions for a particular device. They found the filters to be suitable for applications in the 1-10 gigahertz frequency range. According to the team the filters can be designed for other frequencies, including in the megahertz range…read […]

New method gives robust transistors

Science Daily  January 7, 2020 The combination of gallium nitride and silicon carbide ensures that the circuits are suitable for applications in which high powers are needed. However, the fit at the surface end up mismatched with each other, which leads to failure of the transistor. The problem was addressed by placing aluminium nitride between the two layers. An international team of researchers (Sweden, France) discovered a previously unknown epitaxial growth mechanism that they have named “transmorphic epitaxial growth.” It causes the strain between the different layers to be gradually absorbed across a couple of layers of atoms allowing grow […]

WPI researchers discover vulnerabilities affecting billions of computer chips

Eurekalert  November 12, 2019 Researchers at Worcester Polytechnic Institute discovered two vulnerabilities located in trusted platform modules, which are specialized, tamper-resistant chips that computer manufacturers have been deploying in nearly all laptops, smart phones, and tablets for the past 10 years. One of them was found in Intel’s TPM firmware, and another in  STMicroelectronics’ TPM. The vulnerabilities have been addressed. They would have allowed hackers to employ timing side-channel attacks to steal cryptographic keys that are supposed to remain safely inside the chips. The recovered keys could be used to compromise a computer’s operating system, forge digital signatures on documents, […]

‘Electroadhesive’ stamp picks up and puts down microscopic structures

Nanowerk  October 11, 2019 Mechanical pick-and-place technologies cannot manipulate smaller objects whose surface forces dominate over gravity, and emerging microtransfer printing methods require multidirectional motion, heating, and/or chemical bonding to switch adhesion. A team of researchers in the US (MIT, University of Pennsylvania) has developed soft nanocomposite electroadhesives (SNEs), comprising sparse forests of dielectric-coated carbon nanotubes (CNTs), which have electrostatically switchable dry adhesion. SNEs exhibit 40-fold lower nominal dry adhesion than typical solids, yet their adhesion is increased >100-fold by applying 30 V to the CNTs. They characterized the scaling of adhesion with surface morphology, dielectric thickness, and applied voltage […]

‘Tsunami’ on a silicon chip: A world first for light waves

Science Daily  July 3, 2019 An international team of researchers (Singapore, Australia) has shown CMOS‐compatible, on‐chip Bragg solitons, with a soliton‐effect pulse compression with a factor of × 5.7, along with time‐resolved measurements of soliton fission on a CMOS‐compatible photonic circuit platform. These observations are enabled by the combination of a unique cladding‐modulated Bragg grating design and the high nonlinearity and negligible nonlinear loss of compositionally engineered ultra‐silicon‐rich nitride (USRN: Si7N3). Manipulating solitons on-chip could potentially allow for the speed up of photonic communications devices and infrastructure…read more. TECHNICAL ARTICLE