Interconnect Applications Research Articles

Communication-Efficient Federated Learning for Digital Twin Systems of Industrial Internet of Things

With the rapid development and deployment of Industrial Internet of Things technology, it promotes interconnection and edge applications in smart manufacturing. However, challenges remain, such as yet-to-improve communication efficiency and trade-offs between computing power and energy consumption, which limits the application and further development of IIoT technology. This paper proposes the digital twin systems into the IIoT to build model between physical objects and digital virtual systems to optimize the structure of IIoT. And we further introduce federal learning to train the digital twins model and to improve the communication efficiency of IIoT. In this paper, we first establish the digital twins model of IIoT based on industrial scenario. Moreover, to optimize the communication overhead allocation problem, this paper proposes an improved communication-efficient distribution algorithm, which speeds up the training performance of federated model and ensures the performance of industrial system model by changing the update training mode of client and server and allowing some industrial equipment to participate in federated training. This paper simulates the real-word intelligent camera detection to validate the proposed method. Comparing our proposed method with the existing traditional methods, the results show the advantages of the proposed method can improve the communication performance of the training model.

Properties of Ultrathin Molybdenum Films for Interconnect Applications

Properties of Ultrathin Molybdenum Films for Interconnect Applications

Preliminary investigation on the correlation between mechanical properties and conductivity of low-density polyethylene/carbon black (LDPE/CB) conductive polymer composite (CPC)

The insulating nature of a polymer can be changed to electrically conductive by incorporating conductive fillers within the polymer matrix to form a conductive polymer composite (CPC). One of the potential application of CPCs are in the area of flexible electronic interconnect application. Nevertheless, the correlation between the electrical conductivity and mechanical properties of CPCs such as tensile was found to be limited. Therefore, this paper is aimed to report the preliminary investigation on the correlation between conductivity and mechanical properties of a low-density polyethylene (LDPE) incorporation with conductive filler which is carbon black (CB. It was observed that the tensile strength was decreased by up to 29.4% and the elongation of break was decreased by up to 90.6% at higher CB loading compared to pure LDPE. Nonetheless, the modulus of elasticity and the electrical conductivity of the composites were increased by up to 150.5% and 16.4% at higher CB loading respectively. Moreover, it was found that the effect of CB additions on the tensile modulus was greater compared to the conductivity of the CPCs.

Improvement of Thermal Stability of NiAl Via Employing Al Capping Layer for Advanced Interconnect Applications

Improvement of Thermal Stability of NiAl Via Employing Al Capping Layer for Advanced Interconnect Applications

Contact Geometrical Study for Top Emitting 980 nm InGaAs/GaAsP Vertical-Cavity Surface Emitting Lasers

Geometrical contacts of a double mesa structure with 16 rows ×15 columns arrays of top emitting GaAs based 980 nm vertical cavity surface emitting lasers (VCSELs) are fabricated and characterized. In this paper, 5 strained In0.22Ga0.78As/Ga0.9AsP0.1 quantum wells (QWs) within λ/2 thick cavity have been employed. The top and the bottom epitaxially grown mirrors are based on the linear graded Al0.9Ga0.1As/GaAs distributed Bragg reflectors (DBRs) with 20.5 and 37 periods, respectively. Static parameters including threshold currents, rollover currents, maximum optical output power and wall-plug efficiency are extracted from light out power-current-voltage (LIV) of VCSELs with fixed oxide aperture diameter of ∅~ 6 μm and various mesa2 diameters. In addition, spectral emission for 980 nm VCSELs of oxide aperture between ∅~ 6 and 19 μm and with fixed ∅~ 6 μm and different bias currents are analyzed. The highest optical output power of around 33 dBm is observed at bias current of 0.8 mA for short−reach optical interconnect applications.

Polarization-tunable compact plasmonic wavelength demultiplexers based on Fano nanoantennas

A compact plasmonic wavelength demultiplexer is an essential prerequisite for practical applications, including the next-generation on-chip devices, near-field optical trapping, and micromanipulation. However, alleviating the polarization dependence of the wavelength demultiplexers remains one of the most challenging issues in realizing such a plasmonic device. Here we propose a gold disk-slit-based compact Fano-type nanoantenna capable of launching surface plasmon polaritons (SPPs) directionally when irradiated under different wavelengths of light, realizing a wavelength demultiplexing function. More importantly, our simulation results show that the shortage of requirement of specific light polarization direction excitation in such wavelength demultiplexers can be circumvented. Furthermore, it is found that the output channel of the SPP can be switched in multiple directions under different polarization excitations. In addition, the results show that the applicable wave band of the wavelength demultiplexing device can be flexibly adjusted by changing the size of the nanoantenna. The technique of introducing the polarization-tunable function into the wavelength demultiplexers in the plasmonic interconnect application enhances the freedom of information transmission and offers a promising building block for future high-speed and high-bandwidth on-chip optical communication.

Understanding electron transport in halogenated graphene nanoribbons and possible application as interconnects

To analyse the suitability of zigzag graphene nanoribbons (ZGNRs) as interconnects, the influence of halogen (F, Cl, Br, and I) passivation on ZGNRs has been analysed in terms of structural stability, electron transport, and thermal conductivity, as well as the performance parameters of the interconnects. The computation is performed using first-principle density functional theory with a non-equilibrium Green’s function approach, while the performance parameters of the interconnects such as delay and power delay product are computed using a HSPICE simulator tool. The formation energy analysis confirms the stability trend for halogen-passivated ZGNRs as F > Cl > Br > I. With moderate stability, the I- and Br-passivated ZGNRs have relatively better current–voltage characteristics in comparison to F and Cl. However, the Cl-passivated ZGNRs have relatively better interconnect parameters in comparison to other proposed halogenated systems (one edge and both edges), measured in terms of kinetic inductance and quantum capacitance. Another requirement of any good interconnect is less delay and less average power, which have also been computed and found to be relatively better in the case of Cl-passivated ZGNRs. Thus, among the halogen-passivated GNRs tested, those that are Cl-passivated defend their selection for interconnect applications well.

Aerosol Jet Printing of Graphene and Carbon Nanotube Patterns on Realistically Rugged Substrates.

Direct-write additive manufacturing of graphene and carbon nanotube (CNT) patterns by aerosol jet printing (AJP) is promising for the creation of thermal and electrical interconnects in (opto)electronics. In realistic application scenarios, this however often requires deposition of graphene and CNT patterns on rugged substrates such as, for example, roughly machined and surface-oxidized metal block heat sinks. Most AJP of graphene/CNT patterns has thus far however concentrated on flat wafer- or foil-type substrates. Here, we demonstrate AJP of graphene and single walled CNT (SWCNT) patterns on realistically rugged plasma-electrolytic-oxidized (PEO) Al blocks, which are promising heat sink materials. We show that AJP on the rugged substrates offers line resolution of down to ∼40 μm width for single AJP passes, however, at the cost of noncomplete substrate coverage including noncovered μm-sized pores in the PEO Al blocks. With multiple AJP passes, full coverage including coverage of the pores is, however, readily achieved. Comparing archetypical aqueous and organic graphene and SWCNT inks, we show that the choice of the ink system drastically influences the nanocarbon AJP parameter window, deposit microstructure including crystalline quality, compactness of deposit, and inter/intrapass layer adhesion for multiple passes. Simple electrical characterization indicates aqueous graphene inks as the most promising choice for AJP-deposited electrical interconnect applications. Our parameter space screening thereby forms a framework for rational process development for graphene and SWCNT AJP on application-relevant, rugged substrates.

A Survey of Instruments and Institutions Available for the Global Governance of Artificial Intelligence

<bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Emerging Technologies Have</b> always challenged traditional regulatory regimes <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</xref> . This is not new nor is this tension likely to change anytime soon given the increasing speed at which embryonic technologies are emerging into the market <xref ref-type="bibr" rid="ref2" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[2]</xref> . Some of these technologies, such as autonomous vehicles or drones, can be effectively regulated at the national level due to clearly defined jurisdictional boundaries and the existence of relevant national and state/provincial regulatory agencies that oversee their conventional counterparts. While the entry of these technologies into the market will challenge regulators and policymakers and may require tweaking of existing regimes, we argue that these technologies, and the products that they enable, will not require a sui generis response at the national and supranational levels. The same cannot be said for artificial intelligence (AI) and the myriad of interconnected and interwoven applications made possible by AI.

Stability- and Crosstalk-Based Performance of Multi- and Double-walled Mixed CNT Bundles as Interconnect for Next-Generation Technology Nodes

The temperature-dependent modeling technique (in the temperature range of 200–500[Formula: see text]K) for a mixed class of carbon nanotube (CNT) bundle interconnects is proposed. The equivalent single conductor (ESC) transmission line models of multi-walled carbon nanotube (MWCNT) and double-walled carbon nanotube (DWCNT) are combined to develop multiple single conductor (MSC) model of mixed CNT interconnects. Various possible arrangements of densely packed MWCNT and DWCNT bundles (MDCB) are considered to form different types of mixed CNT bundle structures (MDCB-1, MDCB-2, MDCB-3 and MDCB-4). The integrated circuit emphasis simulation is performed and the performances of these mixed CNT bundle interconnects are investigated in terms of propagation delay (with and without crosstalk), power dissipation, power-delay product (PDP). Switching times, overshoot voltages and Nyquist plots are analyzed to check the stability of these mixed CNT structures for global interconnect length for 32-nm, 22-nm and 16-nm technology nodes. It is observed that the MDCB-1 structure yields the most promising result in all aspects for interconnect applications in the near future.

Preparation and performance of (Co, Mn)3O4 spinel coating on Crofer alloy by composite electrodeposition and step‐heating thermal conversion

The preparation and performance improvement of the spinel coating on the surface of ferritic alloy is of wide interest for its application in the metallic interconnects of the solid oxide fuel cells (SOFCs). The CoMn2O3 composite coating is prepared on the surface of the Crofer alloy by the composite electrodeposition method. A step‐heating thermal conversion process is subsequently used to convert the composite coating into a spinel coating, while a direct‐heating process is implemented as the control experiment. Isothermal oxidation tests are then carried out for the prepared samples in order to present the high temperature performance. Scanning electron microscopy (SEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and area‐specific resistance (ASR) are used to analyze the properties of the matrix and coatings. The experimental results reveal that the coatings by step‐heating thermal conversion exhibit better performance of electrical conductivity and oxidation resistance than the coatings by direct‐heating process. Furthermore, with the increase of oxidation time, the atomic proportion of Cr element diffusing to the surface of the matrix is maintained at about 3%–4% for the samples with spinel coatings by step heating, which effectively prevent the Cr volatilization in the matrix. The preparation of spinel coatings on the ferritic alloy by composite electrodeposition and step‐heating thermal conversion is helpful to stimulate new ideas for the development of reliable and cost‐effective metallic interconnect.

(Invited) Area-Selective Atomic Layer Deposition for Interconnect Applications

As the semiconductor industry is approaching the 5nm node technology, conventional patterning schemes cannot meet the ever-increasing requirements for alignment imposed by device miniaturization. Area-Selective Deposition (ASD) can potentially alleviate such manufacturing challenges by enabling bottom-up material deposition. The most used and successful approach to achieve ASD envisage a combination of Atomic Layer Deposition (ALD) and surface passivation, such as, self-assembled monolayer (SAM).Among the potential applications, dielectric on dielectric (DoD) ASD emerged as one of the most important for multilayer nano interconnects (e.g.: enabling fully self-aligned vias). In this context, along with the difficulties encountered in preserving a confined material growth, the challenges extend to the fact that the deposited dielectric must exhibit well-defined properties, such as low-dielectric constant. Indeed, the integration an interconnect dielectric deposition process in an ASD scheme is arduous. Vapor-phase deposition of SiO2-like materials typically requires high process temperature as well as strong oxidants or O2-plasma. These are not compatible with the organic passivation films exploited to create well-distinguished local surface chemistries, which is essential to enable selective-material deposition.In this talk, 1-octadecanethiol (ODT) well-known selective chemisorption on Cu over SiO2 is exploited to achieve AS-DoD deposition and understand the surface-driven mechanism that enables a selective material growth. In addition, the proposed ASD scheme in combination with nanoscale adhesion force characterization is used to tackle a critical lack in ASD metrology: monitoring the passivation film directly on patterned substrate. Finally, the challenges and results obtained as an ODT-compatible dielectric deposition process for interconnect applications are discussed in this talk.ASD enabled by metal passivation for Hf3N4, Hf-Silicate, Al2O3, and Al-silicate ALD are explored and presented on Cu/SiO2 patterned substrates, with critical dimension as low as 10nm.

Fe doped Ni–Co alloy by electroplating as protective coating for solid oxide fuel cell interconnect application

To obtain higher electrical conductivity and lower area specific resistance (ASR), the 10% Fe doped Ni–Co (NCF) alloy was prepared on SUS 430 steel substrate by electroplating for solid oxide fuel cells (SOFCs) interconnects application. Then, the SUS 430 steels and NCF coated steels were oxidized at 800 °C. The microstructure and oxide phase of samples were tested by scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). These results proved that the NCF coated steel achieved the lower oxidation rate of 9.28 × 10−14 g2cm−4s−1 and ASR of 14.72 mΩ cm2.

Lisen&Curate: A platform to facilitate gathering textual evidence for curation of regulation of transcription initiation in bacteria

The number of published papers in biomedical research makes it rather impossible for a researcher to keep up to date. This is where manually curated databases contribute facilitating the access to knowledge. However, the structure required by databases strongly limits the type of valuable information that can be incorporated. Here, we present Lisen&Curate, a curation system that facilitates linking sentences or part of sentences (both considered sources) in articles with their corresponding curated objects, so that rich additional information of these objects is easily available to users. These sources are going to be offered both within RegulonDB and a new database, L-Regulon. To show the relevance of our work, two senior curators performed a curation of 31 articles on the regulation of transcription initiation of E. coli using Lisen&Curate. As a result, 194 objects were curated and 781 sources were recorded. We also found that these sources are useful to develop automatic approaches to detect objects in articles by observing word frequency patterns and by carrying out an open information extraction task. Sources may help to elaborate a controlled vocabulary of experimental methods. Finally, we discuss our ecosystem of interconnected applications, RegulonDB, L-Regulon, and Lisen&Curate, to facilitate the access to knowledge on regulation of transcription initiation in bacteria. We see our proposal as the starting point to change the way experimentalists connect a piece of knowledge with its evidence using RegulonDB.

Electrical and mechanical properties of Au–Si bonds for 3D interconnect applications

Driven by high-density and high-reliability demands on three-dimensional (3D) interconnections, electrical and mechanical properties of interconnection structures have been paid more attention. Aiming at the novel enable-3D interconnections realized by Au–Si wafer bonding, this study demonstrates the design, fabrication and test results of testing structures for dimension-define parameters of Au–Si bonds. In order to measure closely-realistic ohmic contact resistances of Au–Si bonds after wafer bonding processes implemented under certain bonding pressures and temperatures, the convex Si structures formed by the local oxidation of silicon process have been designed. Therefrom the specific contact resistance values of Au–Si bonds have been measured as 3.9–8.1 × 10−10Ω m2 for different contact radii (3–20 μm), which indicates the low-resistance potentiality for Au–Si bonds applied on 3D interconnections. On the other hand, two findings on bonding strengths are summarized from finite element simulations and tensile experiments: (a) Au–Si bonding strengths of circular bonding patterns (35–75 MPa) are superior to the ones of square bonding patterns (18–30 MPa) due to the stress concentration phenomenon on four corners of square bonding patterns; (b) there is an inverse relationship between bonding strengths and bonding areas owing to uneven stress distributions in bonding structures. Overall, this study provides a basic optimization design strategy at electrical and mechanical levels for 3D interconnections actualized by Au–Si bonding. Incidentally, these introduced analysis methods are also feasible for homologous Si-based eutectic bonding techniques to extend the forms of 3D interconnections.

Cu doped Ni–Co spinel protective coatings for solid oxide fuel cell interconnects application

Four different amount of Cu doped Ni–Co alloy coatings were fabricated on SUS430 substrate by electroplating for solid oxide fuel cells (SOFCs) interconnects application. After oxidation at 800 °C, the microstructure and oxide phase of samples were tested by scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). Our experimental results indicated that the Cu addition improved the electrical behavior of Ni–Co alloy coating. Cu doping reduced the activation energy (Ea) of electrons hopping and inhibited the growth of Cr2O3 oxide layer. Furthermore, the oxidation kinetics and electrical properties of the alloy coatings were obtained. These results showed that the 9% Cu doped Ni–Co coated steels achieved the minimum parabolic rate constant (2.05 × 10−14 g2cm−4s−1) and area specific resistance (14.11 mΩ cm2) after the thermostatic oxidation process.

Emerging light-emitting diodes for next-generation data communications

The continuing development of consumer electronics, mobile communications and advanced computing technologies has led to a rapid growth in data traffic, creating challenges for the communications industry. Light-emitting diode (LED)-based communication links are of potential use in both free space and optical interconnect applications, and LEDs based on emerging semiconductor materials, which can offer tunable optoelectronics properties and solution-processable manufacturing, are of particular interest in the development of next-generation data communications. Here we review the development of emerging LED materials—organic semiconductors, colloidal quantum dots and metal halide perovskites—for use in optical communications. We examine efforts to improve the modulation performance and device efficiency of these LEDs, and consider potential applications in on-chip interconnects and light fidelity (Li-Fi). We also explore the challenges that exist in developing practical high-speed LED-based data communication systems. This Review examines the development of emerging semiconductor materials—organic semiconductors, colloidal quantum dots and metal halide perovskites—for light-emitting diodes, considering efforts to improve modulation performance and device efficiency, as well as potential applications in on-chip interconnects and light fidelity (Li-Fi).

1D topological systems for next-generation electronics

1D topological systems for next-generation electronics

Reevaluating the Cr Evaporation Characteristics of Ce/Co Coatings for Interconnect Applications

Solid oxide fuel cell (SOFC) is a high-temperature energy conversion device that directly converts the chemical energy of the fuel into electrical energy via electrochemical reactions with a very high efficiency. Corrosion of the interconnects, which leads to high degradation rates, is one of the key issues impeding the commercial success of SOFC. Interconnects are used to provide electrical connection between the individual cells which are stacked together to deliver high power output. Recent developments in materials and manufacturing techniques have significantly reduced the operating temperatures, allowing the use of metallic interconnects. Chromia forming ferritic stainless steels (FSS) are preferred over the other materials owing to a coefficient of thermal expansion (CTE) similar to that of ceramic components, high oxidation resistance, good thermal conductivity, and adequate electrical conductivity of Cr2O3 scale at high temperatures. Nonetheless, the use of FSS as interconnect materials poses some significant challenges.During the operation, the chromia scale grows continuously with time, which in turn increases the resistance across the cell. Moreover, chromia reacts with oxygen in the presence of water vapor to form volatile Cr(VI) species such as CrO2(OH)2. These volatile Cr(VI) species react and get deposited at the triple-phase boundaries hindering the oxygen electrochemical reaction on the cathode, leading to cell degradation, also known as chromium poisoning. Despite the various improvements to the steel composition, chromium evaporation is too high for the long-term operation of SOFC. Applying coatings in a widespread solution to suppress chromium evaporation.Spinel structure-based coatings are considered promising owing to good adhesion and are effective barriers to volatile Cr species and oxygen. (Co,Mn)3O4 spinel oxides deposited using various techniques are widely reported in the literature and are known to reduce Cr evaporation and oxide scale growth. Metallic coatings deposited using physical vapor deposition (PVD) are easier and cheaper in terms of manufacturing and eliminate the need for extra heat treatment step for coating densification used in electrophoretic deposition, dip-coating, and screen printing.PVD CeCo coated steels were reported to reduce the chromium evaporation by about 10 times compared to the uncoated on Sanergy HT, Crofer 22H, AISI 441. Nevertheless, the coated coupons investigated had the coating on the faces, but the edges were uncoated. The uncoated edges contribute to higher chromium evaporation than if the edges were coated. Thus, the reported chromium evaporation of the coated coupons is higher than the real chromium evaporation.To understand the influence of the uncoated edges on the measured chromium evaporation, uncoated coupons and two sets of coated coupons, (1) coated coupons with coated edges and (2) coated coupons with uncoated edges were used in the study. The exposures were conducted in horizontal quartz tube reactors at 800 oC for 500 hours in air humidified with 3 % H2O. The airflow is set at 6 lit/min to achieve a flowrate independent regime in the reactor. To quantify chromium evaporation, Na2CO3 coated denuders were used to capture Cr(VI) species, which were replaced at regular intervals.Although the edges made up to only 4% of the total area, the contribution to chromium evaporation from the edges is significant. The chromium evaporation of the coupons with coated edges is about 50 times lower than the chromium evaporation of the uncoated coupons.

Development of Annealed Mn–Co and Mn–Co–Cu Coated AISI 430 Stainless Steels for SOFC Interconnect Application

Development of Annealed Mn–Co and Mn–Co–Cu Coated AISI 430 Stainless Steels for SOFC Interconnect Application