Interconnect Applications Research Articles

Design and Evaluation Challenges of Conversational Agents in Health Care and Well-being: Selective Review Study.

Health care and well-being are 2 main interconnected application areas of conversational agents (CAs). There is a significant increase in research, development, and commercial implementations in this area. In parallel to the increasing interest, new challenges in designing and evaluating CAs have emerged. This study aims to identify key design, development, and evaluation challenges of CAs in health care and well-being research. The focus is on the very recent projects with their emerging challenges. A review study was conducted with 17 invited studies, most of which were presented at the ACM (Association for Computing Machinery) CHI 2020 conference workshop on CAs for health and well-being. Eligibility criteria required the studies to involve a CA applied to a health or well-being project (ongoing or recently finished). The participating studies were asked to report on their projects' design and evaluation challenges. We used thematic analysis to review the studies. The findings include a range of topics from primary care to caring for older adults to health coaching. We identified 4 major themes: (1) Domain Information and Integration, (2) User-System Interaction and Partnership, (3) Evaluation, and (4) Conversational Competence. CAs proved their worth during the pandemic as health screening tools, and are expected to stay to further support various health care domains, especially personal health care. Growth in investment in CAs also shows the value as a personal assistant. Our study shows that while some challenges are shared with other CA application areas, safety and privacy remain the major challenges in the health care and well-being domains. An increased level of collaboration across different institutions and entities may be a promising direction to address some of the major challenges that otherwise would be too complex to be addressed by the projects with their limited scope and budget.

Investigation on high entropy alloys as interconnect material for intermediate temperature solid oxide fuel cells

Investigation of Solid Oxide Fuel Cells (SOFCs) is receiving great attention due to its higher efficiency and zero environmental pollution during operation. Interconnects are a critical part of the SOFC stack which connects the cells in series and combines the electricity produced. The present study aims to investigate High Entropy Alloys (HEAs) for interconnect application in intermediate temperature SOFC. Towards this, FeCoCrNi, FeCoCrNiMn0.1, FeCoCrNiMn0.5, and FeCoCrNiMn HEAs are prepared by vacuum arc melting and examined for its phase evaluation. Thermal stability, thermal expansion, resistivity, oxidation, and Area Specific Resistance (ASR) are investigated up to 800 °C. Oxidation studies show the formation of multicomponent oxide in the HEAs which suppresses the growth of Cr2O3 layer. FeCoCrNiMn0.1, FeCoCrNiMn0.5, and FeCoCrNiMn HEAs possess ASR values less than 100 mΩ.cm2 in the temperature range of 600–800 °C which ensure the superior performance of the SOFC stack.

Performance of CoMnO Spinel Coating onto 441 SS for SOEC Interconnect Application

In this study, CoMnO spinel was applied via atmospheric plasma spray onto 441 SS as SOEC interconnect coating. The performance of oxidation corrosion, electrical resistance, and Cr migration are evaluated. The influence rule was elucidated as the higher the plasma torch power and the thicker coating, the higher the deposition efficiency for the coated specimens. The long-term isothermal oxidation measurement was conducted under a simulated environment for 504 h. The CoMnO35 specimen had a small kp at 6.54 × 10−5 mg2 cm−4 h−1 below the CoMnO30 (7.1 × 10−5) one, and the bare steel sample (1.3 × 10−3). The area-specific resistance (ASR) depends on the temperature and time measured. The CoMnO35 specimen had a smaller Ea (0.61 eV) than the bare steel sample (0.91 eV) and CoMnO38 (0.85 eV). In addition, the CoMnO35 had a lower ASR (27.33 mΩ cm2) than the uncoated one (1.58 Ω cm2 for 670 h).

Dual near-zero-thickness sealing for the strengthening of cobalt thin films and nanolines for future interconnect applications

Self-assembled monolayers (SAMs) and self-forming barriers are molecularly thin surface functional coatings and could be a viable option for enhancing the reliability of thin Co films and Co nanolines. Here, we present an all-wet metallization process which enables electroless-plated Co films to be protected by an amino-based SAM coating and self-forming manganese monoxide (MnO) alloy. Co or lightly alloyed (0.1 % MnO) Co was deposited on the SAM barrier on NiSi/Si, denoted Co [or Co(MnO)]/SAM/NiSi/Si. The two types of samples were annealed to some extent for the evaluation of their thermal stability, primarily using (scanning) transmission electron microscopy [S(TEM)]. For the Co/SAM/NiSi/Si after annealing, the SAM barrier retains its integrity, but it alone is insufficient to prevent interface diffusion and chemical reactions of Co and Si. A three-nanolayered structure, CoSi2(CoSi2−x)/CoSi2/Co2Si, is formed beneath the SAM; faceted CoSi precipitates with a three-domain structure are found above the SAM. By contrast, the Co(MnO)/SAM/NiSI/Si is stable under identical annealing without interface diffusion and chemical reactions. Significant enhancement of electromigration reliability of Co nanolines by the tiny MnO alloying is confirmed by activation energy measurements, and the mechanism for the enhancement is thoroughly elucidated by S(TEM).

Fully controllable multichannel waveguides induced by counterpropagating Bessel beams

We theoretically analyze the waveguiding structures photo-induced by two incoherent counter-propagating Bessel beams (BBs) in a biased photorefractive crystal. We demonstrate that the cross-coupling of two BBs enables adressable channels and tunability of the forming guiding structures. The truncation parameter of the BBs, their Bessel orders and the misalignment between the two beams are all key parameters for tailoring the characteristics of the photo-induced waveguides such as the number of outputs, the output intensity levels and the distance between each output channel. Accordingly, we optimized the different parameters for designing not only a fully tunable Y-coupler but also optical splitters with up to five outputs and even more complex star couplers for all-optical interconnect applications. Finally, we report on the stability behavior of the photo-induced platform. The stability threshold depends on the nonlinearity parameter beyond which the beams display time-periodic, quasi-periodic and turbulent dynamics where spatially localized instabilities can be observed. All these results suggest more opportunities for fully controllable complex waveguiding structures and new all-optical solutions for active components in optical telecommunication and innovative ways of performing optical computing based on spatiotemporal chaos.

Polycrystalline silicon PhC cavities for CMOS on-chip integration

In this work, we present an on-chip 2D and 3D photonics integration solution compatible with Front End of Line integration (FEOL) using deposited polycrystalline silicon (poly:Si) for optical interconnects applications. Deposited silicon integration on a bulk silicon wafer is here discussed in all its processing steps and configurations. Moreover, results of deposited silicon high-Q Photonic Crystal (PhC) resonators are shown, demonstrating the possibility to employ optical resonators patterned on this material in the next generation of 2D and 3D integrated optical interconnects.

(Invited) Computational Insights to Dielectric Hybrid Glasses Under Nanoscale Confinement for Next Generation Devices

Low and Ultra-k dielectric organosilicate glasses (OSG) are widely used in device interconnect applications such as shallow trench isolation as insulating units. However, the process of gap filling between conducting units has been challenging. One of the challenges is related to the undesired formation of nanovoids in the low-k dielectric material confined inside the trench geometry. Importantly, the effects of such nanoscale device constraints on the structure and mechanical reliability of low-k dielectric hybrid materials are not very well understood. To close this lack of understanding and guide the related experimental efforts we performed molecular dynamics simulations where we explore the role of the molecular structure and connectivity of different low-k dielectric OSG precursors under nanoscale confinement, and predict the resulting elastic and fracture properties. We demonstrated that hyperconnected OSG precursors with aromatic rings, such as the 1,3,5-benzene molecule, pack more homogenously under confinement leading to smaller nanovoids and better mechanical reliability compared to conventionally bridged OSG precursors, such as the ethylene bridged Et-OCS molecule.

(Invited) Status of Room-Temperature Mass-Production Capability Plasma-Based Copper Etch Process

Copper (Cu) dominate interconnect applications in advanced ICs, large-area flat panel displays, and other microelectronics for its high conductivity, long lifetime, and plenty of raw material supply at the low cost. It is preferable that Cu arrow lines are prepared with the plasma etching method. However, due to the low volatility of the Cu halide or organic compound in the plasma reaction, there is lack of practical manufacturable etching process that satisfies requirements on large-area, high-throughput, room-temperature, simple, and low cost.Since IBM introduced the CMP Cu etching method (1), it has been widely adopted in IC production. This a tedious process that involves sputter and electroplating depositions, dielectric etching, mechanical polishing, and environmental unfriendly slurry solutions. There are challenges in endpoint detection, dishing, and preparing very fine lines.We first reported a 2-step plasm-based Cu etch process that could be conducted at room temperature under the typical plasm etching condition without requiring high-density plasma or extra power source (2,3). Instead of spontaneously removing the plasma-Cu reaction product, the Cu film is converted into a compound at a high rate, which is then dissolved in an acid or alkaline solution. Being described as a disruptive technology, this process has been successfully demonstrated in the fabrication of CMOS hips, TFT LCD panels, and sub 0.5 μ lines (4,5).Recently, we published a new process that replaces the corrosive chlorine- or bromine-containing feed gas with oxygen (6). The new process can reduce the production cost, e.g., no need of corrosion-resistant tubes, valves, flow controllers, and pumps. The large-area and high throughput advantages are maintained in the new process.In this talk, the principle of the oxygen or halogen plasma-based Cu etch process will be discussed with respect to the reaction mechanism, material properties, and limitations. Possible future development of this technology will be examined. https://www.chiphistory.org/ibm-s-development-of-copper-interconnect-for-icsKuo and S. Lee, ECS Proc. 99–30, 328 (1999).Kuo and S. Lee, Jpn. J. Appl. Phys. 39, L188 (2000).Kuo, Proc. 16th Intl. Workshop AM-FPD Dev, 211 (2009).Kuo, ECS Trans. 66, 139 (2015).Y. Kuo and J. Q. Su, Jpn. J. Appl. Phys. 61, 030902 (2022).

(Invited) Chemistry Effects on the Electrodeposition of Re, Co, and Alloys

Electrodeposition has been adopted in various metallization processes. It allows conformal and super-conformal deposition on curved and recessed substrates, enables the fabrication of metals and alloys with well controlled composition, impurity, and grain structure, and provides fast growth rate, high throughput, and low cost of ownership. Organic additives have been used in electrolytes to tune not only the growth behavior, but also the impurity and grain structure of the deposited material. The most well-known cases are those used for magnetic alloy plating[1,2] in storage and MEMS industry and for damascene copper plating[3,4] in microelectronic industry. On the other hand, the electrolyte itself has largely remained aqueous for most cases. Organic solvents, room temperature ionic liquids, and deep eutectic systems have been widely studied with, however, relatively limited success in large scale adoption.The first part of this talk will introduce some studies on the electrodeposition of Cobalt as an alternative metal for semiconductor interconnect applications. Organic additives that tailor the deposition rate of cobalt are used to enable the Co filling in sub-micron structures. The effect of such additives on the impurity incorporation and film grain structure will be discussed. The second part of the talk will discuss some recent studies on the electrodeposition from “water-in-salt” electrolytes, where the hydration of a super high concentration of supporting salt depletes the free water molecules in the aqueous solution, thus limiting the hydrogen evolution reaction. The discussion will be in a context of Re and ReCo alloy deposition for superconducting connector applications for quantum devices. REFERENCES T. Osaka, M. Takai, K. Hayashi, K. Ohashi, M. Saito, and K. Yamada, A soft magnetic CoNiFe film with high saturation magnetic flux density and low coercivity, Nature, 1998, 392(6678), 796. E.I. Cooper, C. Bonhôte, J. Heidmann, Y. Hsu, P. Kern, J.W. Lam, M. Ramasubramanian, N. Robertson, L.T. Romankiw, and H. Xu, Recent developments in high-moment electroplated materials for recording heads, IBM Journal of Research and Development, 2005, 49(1), 103. P. Andricacos, C. Uzoh, J. Dukovic, J. Horkans, and H. Deligianni, Damascene copper electroplating for chip interconnections, IBM Journal of Research and Development, 1998, 42(5), 567. T.P. Moffat, J.E. Bonevich, W.H. Huber, A. Stanishevsky, D.R. Kelly, G.R. Stafford, and D. Josell, Superconformal Electrodeposition of Copper in 500–90 nm Features, Journal of The Electrochemical Society, 2000, 147, 4524.

Present Status and Prospect of Graphene Interconnect Applications

Present Status and Prospect of Graphene Interconnect Applications

The suitability performance of Sr2Fe1.5Mo0.5O6-δ-coated SUS430 for SOFC interconnect application

430 stainless steel (SUS430)-Sr2Fe1.5Mo0.5O6-δ (SFM) composite interconnect materials have been successfully synthesized by a facile powder metallurgy method. SFM powder synthesized by sol–gel method was coated on SUS430 stainless steel matrix and sintered to obtain SUS430-SFM material. After circulating oxidation at 800 °C for 140 h in air, the oxidation rate constant K and current density of the interconnect materials were 3.66 × 10-14 mg2·cm−4·s−1 and 1.296 × 10-7 A·cm−2, lower than those of SUS430 stainless steel. Its conductivity was about 5.8 × 103 S·cm−1, about twice of that of SUS430 sample. This excellent performance is due to the good matching of thermal expansion between the coating and the substrate and the excellent oxidation resistance of the coating.

Wavelength-Division Multiplexing on an Etchless Lithium Niobate Integrated Platform

Arrayed waveguide gratings (AWGs) are widely used as (de)multiplexers in wavelength-division-multiplexed optical communication systems and as integrated spectrometers in optical sensing and imaging systems. Lithium niobate integrated photonics is a burgeoning field due to many excellent optical properties of lithium niobate and rapid development of wafer processing technologies. Here, we introduced a new strategy of low-loss waveguiding on an etchless lithium niobate integrated platform for realizing high-performance AWGs thereon. We experimentally demonstrated 4-, 8-, and 16-channel AWGs operating in both telecom and near-visible wavelength bands on the etchless lithium-niobate-on-insulator platform. All the channels have insertion losses below 9.1 dB and crosstalks less than −12.8 dB in the designed wavelength bands. With advantages of an ultrawide transparency window and strong electro-optic and nonlinear optical coefficients of lithium niobate, the demonstrated AWGs will find wide applications in on-chip high-capacity optical interconnects, ultrafast bioimaging, LiDAR, and astronomical spectrographs.

Study on CoAl intermetallic compound films for advanced interconnect applications: Experimental and DFT investigations

This paper reports the results of a materials study on co-sputtered CoAl thin films for interconnect applications based on both experiments and computations. We modulate the composition and microstructure of the CoAl films by controlling the deposition conditions (sputtering power, substrate temperature, and deposition time). The morphology and microstructure of the films are investigated using scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The measurement of the film resistivity reveals a strong stoichiometry effect: the lowest (∼30 μΩ∙cm) for the stoichiometric film. It also discloses a typical trend of size dependence: the resistivity increases rapidly with the thickness decreasing (from 38 μΩ∙cm for 43 nm to 72 μΩ∙cm for 13 nm). We also compute the resistivity dependence on the film thickness by solving the Boltzmann transport equation with inputs of the electronic and phononic structures from the first-principles density functional theory and the electron-phonon relaxation time modified according to the film thickness. Furthermore, we devised a simple model considering the effects of grain sizes and scattering at grain boundaries on the resistivity to describe the transport behavior in CoAl. Our calculated results were found consistent with our experimentally observed ones.

Technologies for Interoperable Internet of Medical Things Platforms to Manage Medical Emergencies in Home and Prehospital Care: Protocol for a Scoping Review.

BackgroundPopulation growth and aging have highlighted the need for more effective home and prehospital care. Interconnected medical devices and applications, which comprise an infrastructure referred to as the Internet of Medical Things (IoMT), have enabled remote patient monitoring and can be important tools to cope with these demographic changes. However, developing IoMT platforms requires profound knowledge of clinical needs and challenges related to interoperability and how these can be managed with suitable technologies.ObjectiveThe purpose of this scoping review is to summarize the best practices and technologies to overcome interoperability concerns in IoMT platform development for medical emergencies in home and prehospital care.MethodsThis scoping review will be conducted in accordance with Arksey and O’Malley’s 5-stage framework and adhere to the PRISMA-P (Preferred Reporting Items for Systematic Reviews and Meta-analyses Protocols) guidelines. Only peer-reviewed articles published in English will be considered. The databases/web search engines that will be used are IEEE Xplore, PubMed, Scopus, Google Scholar, National Center for Biotechnology Information, SAGE Journals, and ScienceDirect. The search process for relevant literature will be divided into 4 different steps. This will ensure that a suitable approach is followed in terms of search terms, limitations, and eligibility criteria. Relevant articles that meet the inclusion criteria will be screened in 2 stages: abstract and title screening and full-text screening. To reduce selection bias, the screening process will be performed by 2 reviewers.ResultsThe results of the preliminary search indicate that there is sufficient literature to form a good foundation for the scoping review. The search was performed in April 2022, and a total of 4579 articles were found. The main clinical focus is the prevention and management of falls, but other medical emergencies, such as heart disease and stroke, are also considered. Preliminary results show that little attention has been given to real-time IoMT platforms that can be deployed in real-world care settings. The final results are expected to be presented in a scoping review in 2023 and will be disseminated through scientific conference presentations, oral presentations, and publication in a peer-reviewed journal.ConclusionsThis scoping review will provide insights and recommendations regarding how interoperable real-time IoMT platforms can be developed to handle medical emergencies in home and prehospital care. The findings of this research could be used by researchers, clinicians, and implementation teams to facilitate future development and interdisciplinary discussions.International Registered Report Identifier (IRRID)DERR1-10.2196/40243

Vapor phase synthesis of topological semimetal MoP2 nanowires and their resistivity

Topological semimetals (TSMs) possess topologically protected surface states near the Fermi level with high carrier densities and high mobilities, holding distinct potential for low-dissipation on-chip interconnects that may outperform current copper interconnects for continued dimensional scaling of CMOS technologies. To translate the exotic properties of TSMs into practical interconnects, developments of high precision synthesis for these emergent semimetals are essential. Here, we report the synthesis of TSM molybdenum diphosphide (MoP2) nanowires with controlled dimensions and crystallinity. By varying the growth temperature in chemical vapor depositions (CVD), we achieve polycrystalline MoP2 as well as single-crystalline MoP2−x nanostructures, which are confined in highly anisotropic forms on crystalline substrates with a miscut angle of 1°. The measured metallic properties, such as room temperature resistivity and temperature-dependent resistance, of the synthesized MoP2 nanostructures show promising dimensional effects for interconnect applications, suggesting potential enhancement of topological surface states in electron transport at reduced dimensions. The demonstration of CVD-grown MoP2 nanowires provides opportunities for careful investigations of design rules for TSMs-based nanoscale interconnects.

Ce-doped (Mn,Co)3O4 coatings for solid oxide fuel cell interconnect applications

In order to improve the electrical conductivity of solid oxide fuel cell (SOFC) interconnect coatings, a series of Ce-doped (Mn,Co)3O4 (Mn1.5-xCo1.5-xCe2xO4+δ, x = 0, 0.025, 0.05, and 0.1) coatings are prepared. The chemical composition, lattice structures, morphology, electrical properties, and weight gain of the coatings are characterized. Experimental results show that doping Ce lowers the area-specific resistance of (Mn,Co)3O4 coatings from 6.83 to 2.62 mΩ cm2 at 800 °C. The electrical conductivity improvement can be attributed to the ion substitution by Ce3+ that turns (Mn,Co)3O4 into (Mn,Co)2CeO4, an N-type semiconductor with a higher electrical carrier density. However, the coatings with heavier doping of Ce exhibit more structural defects due to the lattice parameter reduction and volume shrinkage, which weaken the oxidation resistance of the coatings. This study verifies that doping Ce can effectively improve the electrical conductivity of spinel coatings. The negative influence of doping Ce can be mitigated by modifying the coating preparation technique or by changing the SOFC operating temperature.

Low-Loss Silicon Photonic 16 × 16 Cyclic AWGR Based on SOI Platform

We experimentally demonstrate a low-loss and low-crosstalk 16-channel 200 GHz-channel-spacing arrayed waveguide grating router (AWGR) with a size of 0.67 × 0.37 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , targeting for C-band wavelength division multiplexing (WDM) interconnect routing applications. As a result, the AWGR features a channel spacing of 200±10 GHz, a free spectral range of 25.62 nm and a 3 dB channel bandwidth of 0.9 nm. Based on comprehensive optimal design, the measured characterization revealed 5.55 dB maximum channel loss non-uniformity with 1.13 dB best-case channel insertion loss. Besides, the fabricated device exhibits good cyclic-frequency operation for all 16 × 16 port combinations with channel crosstalk of –15.11 dB.

Properties of ultrathin molybdenum films for interconnect applications

The structural and electrical properties of Mo thin films with thicknesses between 3 and 50 nm, deposited by physical vapor deposition, have been evaluated in order to assess the potential of Mo as an alternative to Cu or W for nano-interconnect applications. Mo films deposited on SiO2/Si (100) were polycrystalline with randomly oriented grains close to the interface and the progressive formation of a (110) texture above 5 nm film thickness. Adhesion between Mo and low-κ dielectrics was strong with adhesion energies above 5 J/m2. The films showed intrinsic tensile stress of ∼1 GPa, which decreased with increasing thickness. The Mo resistivity showed a weaker thickness dependence than Cu, which rendered Mo competitive with conventional TaN/Cu/TaN metallization below metal thicknesses of 8 nm. Semiclassical resistivity modeling found that the thin film resistivity was limited by grain boundary scattering with a reflection coefficient of R = 0.46 ± 0.03. Furthermore, the effects of Mo deposition on different dielectric and metallic substrates and of post-deposition annealing up to 950ºC were investigated. Crystallinity, impurity concentration, and resistivity were all affected by the substrate. Post-deposition annealing in H2 led to continuous grain growth, followed by recrystallization at 860ºC. Furthermore, annealing at 650°C led to compressive stress in the films. By contrast, annealing in H2/N2 led to the incorporation of N and ultimately to Mo nitride formation above 500ºC. The results indicate that Mo can be a promising candidate for advanced interconnect metallization schemes if surface oxidation as well as impurity incorporation can be kept under control.

High-speed performance evaluation of ultra-flexible polymer waveguides supporting meter-scale optical interconnects.

We demonstrate bandwidth measurement and high-speed data transmission of meter-scale connectorized ultra-flexible multimode waveguide links with a maximum length of 180 cm. The pulses propagating through the waveguides broadened linearly with the increase of the length from 20 cm to 240 cm and the estimated mode delay from the pulse broadening was 0.093 ps/cm. The corresponding waveguide bandwidth decreased inversely with the increase of waveguide length, leading to a bandwidth-length product of 42 GHz·m. Degradation in bandwidth due to the introduction of bending or twisting was small when the samples were bent with a bending radius as small as 1 mm for 3 turns or twisted for 4 full turns, respectively. Error-free transmission of 30 Gb/s non-return-to-zero (NRZ) signal was achieved with a record link length up to 140 cm to the best of our knowledge. Our results show that the demonstrated flexible waveguides have both excellent optical and mechanical properties and are ideal for high-speed optical interconnects application especially those have a strict requirement on flexibility.

High-entropy FeCoNiMnCu alloy coating on ferritic stainless steel for solid oxide fuel cell interconnects

A high-entropy alloy coating of FeCoNiMnCu was prepared on SUS 430 steel via magnetron sputtering for solid oxide fuel cell (SOFC) interconnects application. The coated steels were subject to thermal exposure in air at 800 °C for up to 10 weeks. Phase constituents, microstructure and area specific resistance (ASR) of the coated steel before and after the oxidation testing were investigated. Results indicated the alloy coating was thermally converted into a high-entropy spinel coating of (Fe,Co,Ni,Mn,Cu) 3 O 4 after oxidation and a protective Cr 2 O 3 layer was formed at the steel/coating interface. The (Fe,Co,Ni,Mn,Cu) 3 O 4 spinel coating effectively suppressed growth of Cr 2 O 3 layer and outward diffusion of Cr during the long term exposure. Scale ASR of the coated steel was as low as 6.59 mΩ·cm 2 at 800 °C after 10 weeks. It indicates that (Fe,Co,Ni,Mn,Cu) 3 O 4 is a promising coating material for SOFC metallic interconnects. • A high-entropy alloy coating of FeCoNiMnCu is sputtered on SUS430 steel. • The coating is thermally converted into a high-entropy (Fe,Co,Ni,Mn,Cu) 3 O 4 spinel. • The spinel coating effectively suppresses growth of Cr 2 O 3 and out-diffusion of Cr. • Area specific resistance of coated steel is sufficiently low after long term exposure.