Microelectronic Technology Research Articles

Long-term Implanted Flexible Neural Interfaces for Electrophysiological Monitoring

With the rapid advancements in materials science, engineering, and microelectronics technology, intelligent dynamic prostheses, guided by motion intention, are progressively replacing conventional prosthetic solutions. Implanted interfaces within the neuromuscular system—including...

Design of Multilayered XOR Gate Using Quantum Dot Cellular Automata

The rapid advancement of microelectronics technology necessitates the development of high-speed, low-power devices. Quantum Cellular Automaton (QCA) is emerging as a promising technology enabling logic circuits with exceptional operating speeds. The XOR gate is crucial in nanocomputing applications, such as nano-processors and nano-communication units, and requires innovative design approaches. This paper presents a novel design of an XOR gate using a multilayered layout methodology within the QCA framework. The circuit’s design and validation are performed using QCADesigner 2.0.3, while energy dissipation analysis is conducted with QCADesigner-E, resulting in an energy dissipation of 15 meV. Comprehensive parameter analysis, including cost functions, highlights the superiority of the proposed design. A comparative analysis with similar existing multilayered designs shows a 55% improvement in QCA-specific quantum cost. Notably, the proposed design eliminates the need for internal nodes within the layout, enhancing the methodology’s applicability to higher-order and more complex circuits.

Numerical investigation on the flow and heat transfer performances of a novel microchannel heat sink arranged with inclined pin fins

Abstract The advancement of microelectronics technology has led to an increased demand for heat dissipation in devices. In response to this challenge, microchannel heat sinks (MCHS) have been introduced as a viable solution. The heat dissipation capabilities of MCHS can be enhanced by adopting pin fins, which serve to augment the solid-liquid contact area and disrupt the fluid boundary layer. Most research on MCHSs with pin fins has concentrated on vertical pin fin configurations, with a comparatively limited investigation into inclined pin fins. To further enhance the thermal performance of MCHS with pin fins, this study presents a novel MCHS with inclined pin fins (MCHS-IPF). The flow and heat transfer characteristics under steady-state conditions were analyzed using three-dimensional numerical simulations. Additionally, geomet-ric optimization was conducted on the tilt angle (θ: 30° to 30°, excluding 0°) and the secondary flow channel width ratio (β) to achieve improved overall performance. The results show that the MCHS-IPF sig-nificantly enhances thermal dissipation capability compared to a conventional MCHS with vertical pin fins (MCHS-VPF). As the tilt angle remains constant, the heat dissipation capacity of MCHS-IPF improves with an increase in β. The MCHS-IPF with β = 0.6 and θ = 30° at Re = 600 shows a notable enhancement of 57.7% in the Nusselt number compared to the MCHS-VPF. This MCHS-IPF, also demonstrates superior overall performance in this study, achieving a maximum Performance Evaluation Criteria of 1.53, thereby establishing itself as the optimal structure.

Effects of Aromatic Surfactants on Tin Electrodeposition

As the technology of quantum computing continues to develop, the necessity of finding materials that can be used to integrate the superconducting 3D architecture becomes more essential1. The electrodeposition of metals demonstrates an attainable way to manufacture vertical superconducting interconnects. In particular, Sn is one of the promising candidates to use because of its relatively high superconducting transition temperature (Tc) at 3.7 K, as well as its excellent manufacturability and self-passivation2. To ensure a void-free filling of the via like structure, organic additives that can function as suppressors, accelerators, or levelers will be needed to tune the deposition rate in the structure. While multi-additive systems have been used to control the deposition and the fabrication of conventional Cu interconnect structures, in other cases it has been demonstrated that a single additive can also enable the filling of Cu vias by suppressing the deposition at a certain range of potentials with a breakdown of the suppression occurring at another range3-4. Because of the importance of suppressive additives used in superconformal deposition, this work looks to explore the relationship between the degree of aromaticity and the level of suppression in additive assisted electrochemical deposition of Sn. Organic surfactant molecules including Igepal CO 520 and ethoxylated α-napthalenesulfonic acid (ENSA-6) are used for the comparative study in acidic stannous sulfate electrolytes.The effects of the additives on the deposition are studied using cyclic voltammetry and chronoamperometric measurements. Both Igepal and ENSA-6 were able to suppress the deposition of tin while additives with similar molecular weight but no aromatic rings appear to have little impact. Furthermore, the suppression increases with concentrations of the additives, with varying degrees of aromaticity showing a slight difference in suppression strength. Finally, the adsorption and desorption of the additives as well as the deposition transients are studied by varying voltage sweep rate and electrode agitation, the results will be discussed in details. References Yanay, Y., Braumüller, J., Gustavsson, S., Oliver, W. D., & Tahan, C. (2020). Two-dimensional hard core Bose–Hubbard model with superconducting qubits. Npj Quantum Information, 6(1).Huang, Q. (2023). Superconductivity of electrodeposited Sn films. Journal of The Electrochemical Society, 170(3), 032506.Radisic, A., Lühn, O., Philipsen, H. G. G., El-Mekki, Z., Honore, M., Rodet, S., Armini, S., Drijbooms, C., Bender, H., & Ruythooren, W. (2011). Copper plating for 3D interconnects. Microelectronic Engineering, 88(5), 701–704.Moffat, T. P., & Josell, D. (2012a). Extreme bottom-up superfilling of through-silicon-vias by damascene processing: Suppressor disruption, positive feedback and Turing patterns. Journal of The Electrochemical Society, 159(4).

CNT/GO Zinc Composite as Dual-Functional Electroconductive and Lithophilic Coatings for Cu-Current Collectors in Anode-Free Li Batteries

The novel concept of anode-free lithium batteries (AFLBs), which eliminate excess lithium while preserving numerous advantages, presents certain challenges such as notable capacity loss, low electronic conductivity, and reduced coulombic efficiency. To address these issues, modified lithiophilic current collectors are essential for enhancing electrochemical performance. This study focuses on surface modification of the copper current collector through carbonaceous zinc composites co-electrodeposition benefiting lithiophilicity and electroconductivity [1]. These composites, including 1D Zn/Carbon Nanotubes (CNT-Zn) and 2D Zn/Graphene Oxide (GO-Zn), are coated on the copper current collector, varying their compositions to create a lithiophilic thin layer and improve electroconductivity [2-3]. The aim of this modification is to promote smoother plating and stripping processes, thereby facilitating uniform lithium deposition without dendrite formation. The composite-modified current collector demonstrated improved cyclability over 200 cycles at 0.393 mA, reduced overpotential at various applied current densities (ranging from 0.392 to 1.962 mA cm-2), and provided uniform lithium deposition. Electrochemical Impedance Spectroscopy (EIS) revealed the most reduced charge transfer resistance (Rct) of 38.4 Ω for Zn/Graphene Oxide (GO-Zn) after the first cycle. It also indicated that a higher amount of CNT and GO leads to worse electrochemical performance due to the agglomeration of carbonaceous particles on the substrate.References Pooria Afzali, Eugenio Gibertini, Luca Magagnin, Improved plating/stripping in anode-free lithium metal batteries through electrodeposition of lithiophilic zinc thin films,, Electrochimica Acta, Volume 488,2024,144190, ISSN 0013-4686, https://doi.org/10.1016/j.electacta.2024.144190.Ge J, Hong J, Liu T, Wang Y. Rational design of a self-supporting skeleton decorated with dual lithiophilic Sn-containing and Ndoped carbon tubes for dendrite-free lithium metal anodes. J Mater Chem A 2022;10:11458-69.Mehmet Oguz Guler, Tugrul Cetinkaya, Ubeyd Tocoglu, Hatem Akbulut, Electrochemical performance of MWCNT reinforced ZnO anodes for Li-ion batteries, Microelectronic Engineering, Volume 118, 2014, Pages 54-60, ISSN 0167-9317, https://doi.org/10.1016/j.mee.2013.12.029

Investigation of Inclusions and Associated Dislocation Configurations in 4H-SiC Wafers through Synchrotron X-Ray Topography and Ray-Tracing Simulation

Silicon carbide (SiC) is a wide bandgap semiconductor that steadily replacing the application of conventional semiconducting materials such as silicon-based devices. Its superior properties such as larger bandgap, higher electron saturation velocity and thermal conductivity [1, 2] enables devices to be more effective and efficient with smaller volume, higher dielectric strength, and lower energy loss [3-5]. The prerequisite of expanding SiC devices industry is to achieve steady manufacture of large-scale, high-quality, polytypic stable SiC substrate wafers. Therefore, understanding the nature and origins of crystallographic defects within SiC is a major research pursuit since those can induce degradation that challenges device reliability while achieving high performance [6]. Synchrotron X-ray topography (XRT) [7, 8] is a powerful non-destructive characterization technique that generate high-resolution X-ray images of the internal structure of a crystal. Crystallographic defects and structural features are then revealed as topographic contrast features that can be identified applying contrast formation mechanisms. Extensive studies have been conducted to observe various dislocation configurations, stacking faults, and low-angle grain boundaries using this approach. In this study, optically observable hexagonal features on a 6-inch 4° off-axis 4H-SiC substrate wafer are investigated through synchrotron XRT in both transmission and grazing-incidence geometries. These hexagonal features are identified as inclusions as correlated topographic contrasts reveal the generation of large strain fields associated with them. Indentation behavior is found to be induced by the presence of inclusions as both regular (9keV) and high energy (18keV) grazing-incidence topographs show arrays of opposite-signed threading edge dislocation (TED) pairs expand from inclusions along <11-20> directions, which is the evidence of the generation of prismatic loop. Basal plane dislocation (BPD) half loops are also observed associated with inclusions. Using ray-tracing simulation technique based on orientation contrast mechanism [9, 10], contrasts of inclusion at different depth and associated dislocations can be simulated and compared to X-ray topographic images. This will provide insights on the behavior of inclusions embedded in SiC as well as the activation of associated dislocations.Reference:[1] Matsunami, H., Current SiC technology for power electronic devices beyond Si. Microelectronic Engineering, 2006. 83(1): p. 2-4.[2] Codreanu, C., et al., Comparison of 3c SiC, 6h SiC and 4H SiC MESFETs performances. Materials Science in Semiconductor Processing, 2000. 3: p. 137-142.[3] Xie L., et al Enhancement of toughness of SiC through compositing SiC–Al interpenetrating phase composites. Nanotechnology, 2020 31 135706[4] Lin K., et al Enhanced mechanical properties of 4H-SiC by epitaxial carbon films obtained from bilayer graphene. Nanotechnology, 2020 31 195702[5] Shen G., et al, Synthesis, characterization and field-emission properties of bamboolike β-SiC nanowires. Nanotechnology, 2006 17 3468–72.[6] Neudeck, P.G., Electrical Impact of SiC Structural Crystal Defects on High Electric Field Devices. Materials Science Forum, 2000. 338-342: p. 1161-1166.[7] Tanner, B.K. and D.K. Bowen, Synchrotron X-radiation topography. Materials Science Reports, 1992. 8(8): p. 371-407.[8] Lang, A.R., The early days of high-resolution X-ray topography. Journal of Physics D: Applied Physics, 1993. 26(4A): p. A1.[9] Huang, X.R., et al., Superscrew dislocation contrast on synchrotron white-beam topographs: an accurate description of the direct dislocation image. Journal of Applied Crystallography, 1999. 32(3): p. 516-524.[10] Dudley, M., X.R. Huang, and W. Huang, Assessment of orientation and extinction contrast contributions to the direct dislocation image. Journal of Physics D: Applied Physics, 1999. 32(10A): p. A139.Figure 1: (a) Optical image showing hexagonal features on the upper region of a 4° off-axis 4H-SiC substrate wafer; (b) synchrotron white beam X-ray topograph recorded in 11-20 transmission geometry for the same region, showing the strain contrast induced by those hexagonal features; (c) synchrotron monochromatic beam X-ray topograph recorded in 11-28 grazing-incidence geometry for the same region, showing contrast of some hexagonal features (marked with blue arrows); (d) enlarged optical image of the hexagonal feature; (e) enlarged 11-28 grazing-incidence synchrotron X-ray topograph showing TED slip bands induced by a hexagonal feature; (f) enlarged 22-4,16 grazing-incidence synchrotron X-ray topograph showing TED slip bands induced by a hexagonal feature. Figure 1

Transformation of the science of Information Law and information legislation: a new stage in the conditions of scientific and technological development of Russia

The authors of the article analyze the current trends in the development of the doctrine of Information Law and information legislation in the context of updated tasks for the scientific and technological development of the Russian Federation. It is noted that in the context of the development of an information society based on the digital economy and the data economy, the transformation of law is taking place, which is largely facilitated by the active evolution of Information Law, the expansion of its subject due to the rapid formation of digital law as a basic institution (an emerging sub-sector) responsible for the features of legal provision of information processes and phenomena in digital form. It is within the framework of this industry that legal support for the digitalization of society takes place both at the expense of basic information and legal norms governing the basic provisions (principles of regulation of digital relations, the regime of digital data and other objects of the digital environment, the legal status of subjects of the digital environment, as well as other legal aspects that reflect the essence of the digital form, the application of which is universal and can be applied in law in general), as well as through industry-specific digital norms developed and adopted within a particular branch of law, reflecting the specifics of the implementation of digital processes in relation to a specific area of public relations, regulated by the relevant branch of law. The main directions of scientific and technological development and the tasks of Information Law are also studied. The authors note that the scientific and technological development of Russia today is based on a number of principles that are important to take into account in the development of information legislation and the science of Information Law. Modern information processes and technologies directly permeate and ensure the functioning of all priority areas of scientific and technological development and are part of or ensure the application of all the most important high-tech technologies. In this regard, it is important to work out and consolidate at the theoretical level in information legislation mechanisms that contribute to the effective implementation of the accelerated development and introduction of these important knowledge-intensive technologies into the economy, including within the framework of national projects to ensure technological leadership. As a result of the analysis of critical and end-to-end technologies, it was revealed that the main emphasis in the development of information legislation and the doctrine of Information Law should be placed on the formation of models for regulating the use of artificial intelligence technologies in economic sectors, the social sphere (including the sphere of public safety) and in public authorities, including the development of regulation of robotics, as well as microelectronics technologies and photonics for information storage, processing, transmission and protection systems, technologies of secure quantum data transmission systems. The authors draw a number of conclusions about the development of the principles of regulation of artificial intelligence, as well as the prospects for the development of legal regulation of the field of robotics. The analysis is given of the discussed problems of Information Law at the Seventh Bachilov Readings, held in 2024 at the Institute of State and Law of the Russian Academy of Sciences.

Определение потенциала развития микроэлектроники в Новосибирской области на основе анализа патентных портфелей организаций

Microelectronics is widely used in various fields of science and technology: in modern control systems, radio engineering devices, devices and automation tools in industry, agriculture, transport and defense purposes. This determines the primary need for the development of this area. The strategy for the development of the electronic industry of the Russian Federation until 2030 is focused, among other things, on promoting Russian electronics to existing and international markets. Thus, the primary task is the legal protection of developments. Patent documents are an objective criterion for assessing the potential of technology development. The article evaluates the dynamics of scientific publications and patenting in the field of microelectronics in the Novosibirsk region, in Russia and in the world. This field is quite developed, the number of scientific publications and patents in the world has grown slightly over the past 20 years. There has been a decrease in the number of Russian patents in general and patents whose copyright holders are organizations registered in the Novosibirsk Region, in particular. This is a result of the deterioration of the political situation in the world. The imposition of economic sanctions against the Russian Federation was the reason why foreign companies were forced to stop investing in both research and development and in the production of Russian electronics. In these circumstances, some Russian companies have switched to protecting their developments in a trade secret mode. The main copyright holders and technology scientists working in electronic industry organizations registered in the region under consideration were also identified. The analysis of the level of development of microelectronic technologies in the Novosibirsk region was carried out, which showed that it corresponds to the world level.

Detecting GNSS spoofing and Re-localization on UAV based on imagery matching

Abstract Due to rapid advancements in global navigation satellite system (GNSS), computer, and microelectronics technologies, there is a growing popularity and widespread promotion of high-performance, cost-effective intelligent UAVs across various applications. Recently, GNSS spoofing attacks have emerged as a significant obstacle hindering the long-term development of UAVs. UAVs rely heavily on unprotected GNSS signals for navigation, making them highly vulnerable to spoofing. This paper presents an algorithm that employs image matching for detecting GNSS spoofing and re-localization on UAVs using a deep learning methodology. This method functions autonomously solely reliance on camera and does not require alterations to the antenna configuration. Utilizing a camera-equipped UAV, we evaluate the likeness between real-time aerial photographs and satellite imagery by leveraging the position information provided by UAV. By identifying disparities between images taken by a spoofing affected drone and authentic ones, the spoofing can be identified using deep neural network models. Upon detecting spoofing, this paper presents a vision-based re-localization method for UAVs. Experimental results demonstrate an approximately 88.4% accuracy of our model in detecting GNSS spoofing attacks within 100 ms and 88% success rate of re-localization with the accuracy of less than 15 m. Our algorithm exclusively depends on publicly accessible satellite imagery, offering an intelligent and efficient approach for detecting UAV GNSS spoofing and re-localization in GNSS denied environment.

Microfabrication Technologies for Nanoinvasive and High-Resolution Magnetic Neuromodulation.

The increasing demand for precise neuromodulation necessitates advancements in techniques to achieve higher spatial resolution. Magnetic stimulation, offering low signal attenuation and minimal tissue damage, plays a significant role in neuromodulation. Conventional transcranial magnetic stimulation (TMS), though noninvasive, lacks the spatial resolution and neuron selectivity required for spatially precise neuromodulation. To address these limitations, the next generation of magnetic neurostimulation technologies aims to achieve submillimeter-resolution and selective neuromodulation with high temporal resolution. Invasive and nanoinvasive magnetic neurostimulation are two next-generation approaches: invasive methods use implantable microcoils, while nanoinvasive methods use magnetic nanoparticles (MNPs) to achieve high spatial and temporal resolution of magnetic neuromodulation. This review will introduce the working principles, technical details, coil designs, and potential future developments of these approaches from an engineering perspective. Furthermore, the review will discuss state-of-the-art microfabrication in depth due to its irreplaceable role in realizing next-generation magnetic neuromodulation. In addition to reviewing magnetic neuromodulation, this review will cover through-silicon vias (TSV), surface micromachining, photolithography, direct writing, and other fabrication technologies, supported by case studies, providing a framework for the integration of magnetic neuromodulation and microelectronics technologies.

Engineering texture and twins of Cu foils preparing by pulse electrodeposition and their properties

The controllable microstructure and the overall performance improvement of electrodeposited nano twinned Cu (nt-Cu) foil are crucial for the sustainable development of high energy density batteries and microelectronics technology. Although pulse electrodeposition (PED) and additives have been widely used in controlling nt-Cu foil, there is still a lack of research on the controllable microstructure of nt-Cu foil and its microstructure depended properties. In this study, nt-Cu foils with different orientations were prepared by adjusting the Toff time and additives during the PED process. The effects of these parameters on the microstructure and comprehensive properties of the nt-Cu foil were studied. The Toff time and polyethylene glycol (PEG)-3-mercapto-1-propanesulfonate sodium salt (MPS)-(chloride ions)Cl− (PEG-MPS-Cl−) additive changed the kinetic parameters of the electrochemical reaction and ultimately affected the reduction rate of Cu2+ and the overpotential of the deposition process. This modulation effectively regulated the nucleation and growth behavior of Cu atoms, thereby reducing the surface roughness of the nt-Cu foil, refining the grains, and forming nano-twins with different orientations. Due to the combined strengthening effect of grain refinement, dislocation, and texture orientation, (111) oriented nt-Cu foil demonstrated remarkable mechanical and frictional wear properties, whereas (220) oriented nt-Cu foil exhibited superior conductivity and corrosion resistance. These findings may offer promising prospects for the controllable design of engineering textures and nano-twin structures of high-performance nt-Cu foil by electrodeposition.

Nanometric Ge Films for Ultrafast Modulation of THz Waves with Flexible Metasurface

AbstractHarnessing confined light on a subwavelength scale within Fano metasurfaces enhances light‐matter interaction on a flexible, low‐loss substrate. This approach enables the integration of ultra‐thin semiconducting films for designing low‐power, ultrafast switchable terahertz, and optical meta devices. Here, an ultra‐thin, ∼λ/6000 germanium overlayers of 25nm or 50nm is thermally evaporated onto a flexible Fano metallic metasurface to achieve ultrafast optical modulation of terahertz radiation. A remarkable 85% modulation depth with an ultrafast speed of 400 GHz is obtained in the resonant transmission. These ultrathin, flexible, and ultrafast functional metasurfaces pave the way for developing flexible terahertz active meta devices based on nanometric scale germanium films, offering the additional advantage of compatibility with complementary metal‐oxide‐semiconductor (CMOS) technology in microelectronics.

Loofah-based self-powered triboelectric nanogenerator-supercapacitor for an integrated self-charging energy system

New urbanization is ushering in a surge in construction and amplifying a substantial demand for urban road development, simultaneously spurring innovation and development of environmentally sustainable power sources. Triboelectric nanogenerator (TENG), a revolutionary technology of energy conversion, efficiently capturing high-entropy energy from the environment and offering the advantages of self-powered and immediacy. Recognizing the critical need to store the energy harvested by TENGs, we present an integrated energy conversion and storage system that combines a loofah-based self-powered rotating TENG (LS-TENG) with a supercapacitor. The maximum instantaneous output power and the corresponding instantaneous power density of the LS-TENG are 0.75 mW and 202.69 mW/m2 at 30 rpm. The supercapacitor, featuring carbon nanotube (CNT) interdigitated electrodes created through microelectronic printing technology, utilizes polyacrylamide (PAM)-lithium chloride (LiCl) as a gel electrolyte (adhesion strength of 16.69 kPa). The supercapacitor is seamlessly integrated onto the back of the LS-TENG’s stator, which effectively simplified the energy conversion and storage system. At a current density of 0.01 mA/cm2, the supercapacitor achieves a high volumetric capacitance of 341.47 mF/cm3, an energy density of 17.07 mWh/cm3, and a power density of 257.07 mW/cm3, with a remarkable capacitance retention rate of 99.12 % after 30,000 cycles at a current density of 0.02 mA/cm2. Furthermore, a concept demonstration of an integrated self-charging energy system is implemented, in which the supercapacitor can be charged at wind speed rate of 3.0 m/s. The proposed integrated energy storage and conversion system makes it ideal for converting and storing wind energy.

Cattaneo-Christov fluxes for nonlinear mixed convective entropy generated Reiner-Rivlin material flow

Thermal and solutal transportation processes involve in tremendous useful applications related to heat exchanger, scientific, micro-electronic device technologies and industry sectors like nuclear reactors cooling, marine engineering, nanotechnology, thin-film technology, biomedical applications and thermal conduction in soft tissue. In view of such useful applications the Cattaneo-Christov analysis for nonlinear mixed convective Reiner-Rivlin material flow in presence of constant applied magnetic field is considered. Heat source, magnetohydrodynamics and radiation are incorporated in energy equation. Cattaneo-Christov flux is employed to discuss the thermal and mass transport characteristics. Entropy calculation in radiating flow is discussed. The proposed non-linear systems are transformed into dimensionless ordinary systems through appropriate transformation. Non-linear ordinary expressions are computed for convergent series solutions through Optimal homotopy analysis technique (OHAM). Graphical interpretations for quantities under interest against pertinent variables are explored. Large magnetic parameter has opposite impact for entropy and fluid flow. An increase of temperature through thermal relaxation time parameter is noticed. Velocity has same trend for both mixed convection and Reiner-Rivlin fluid variables. Reduction in concentration is seen for solutal relaxation time parameter. Temperature enhancement is witnessed in presence of heat generation. Entropy rate enhancement for radiation is observed. Decrease in concentration is noticed for reaction. Entropy rate increases against diffusion variable is enhanced.

Towards the Automation of Non-destructive Fault Recognition: Enhancement of Robustness and Accuracy Through AI Powered Acoustic and Thermal Signal Analysis in Time, Frequency- and Time-Frequency Domains

Non-destructive inspection and analysis techniques are crucial for quality assessment and defect analysis in various industries. They enable for screening and monitoring of parts and products without alteration or impact, facilitating the exploration of material interactions and defect formation. With increasing complexity in microelectronic technologies, high reliability, robustness and thus, successful failure analysis is essential. Machine learning (ML) approaches have been developed and evaluated for the analysis of acoustic echo signals and time-resolved thermal responses for assessing their ability for defect detection. In the present paper different ML architectures were evaluated, including 1D and 2D convolutional neural networks (CNNs) after transforming time domain data into the spectral- and wavelet domains. Results showed that 2D CNNs processing data in wavelet domain representation performed best, however at the expense of additional computational effort. Furthermore, ML-based analysis was explored for lock-in thermography to detect and locate defects in the axial dimension based on thermal emissions. While promising, further research is needed to fully realize its potential.

Transfer of micron pattern with reactive atmospheric plasma jets into fused silica

Pattern transfer by plasma etching is a traditional standard technology in microelectronics and other micron technologies. These technologies require vacuum conditions, which limit throughput, size, and low-cost fabrication. Recent developments in low cost atmospheric plasma technologies may be suitable to realize pattern transfer without vacuum conditions. Reactive atmospheric plasma jet etching has been used to transfer aluminum mask patterns to fused silica. Aluminum line patterns of 2.5 to 50 µm width on fused silica wafer are exposed to a static as well as a scanning CF4/O2 reactive atmospheric plasma jet with a footprint diameter of 0.85 mm (full width at half maximum), resulting in etching only the SiO2 and causing a nearly isotropic etch with an etch rate of about 200 nm/s. As a result, line narrowing, trapezoidal line cross-sections, and under-etching were observed. The successfully transferred line patterns with the demonstrated widths and depths are of technological interest in various fields of application. Therefore, this approach enables low-cost patterning of fused silica through the use of reactive atmospheric plasma jet etching for micron-scale pattern transfer. This advancement addresses the limitations of both traditional vacuum-based and wet etching methods.

Effect of the inclination angles of the capillary tube on the natural evaporation of absolute ethanol

Microchannel heat transfer plays an important role in microelectronics technology for heat dissipation, due to its high efficiency and low heat transfer temperature difference and flow resistance. To underpin the fundamental understanding of this technology, the natural evaporation process of absolute ethanol in a capillary tube at inclination angles ranging from 0° to 90° was investigated experimentally by exploring a spectrum of properties, such as Marangoni flow patterns, evaporation rate, heat flux, and temperature distribution. We found that the morphology of the meniscus is similar under different inclination angles, but the liquid and the tube wall slip to varying degrees due to the pressure difference at the liquid–vapor interface during evaporation. Therefore, the force distribution of the meniscus interface is different, and the resultant force is Fmax(60°) > Fmax(0°) > Fmax(30°) > Fmax(90°). We found that the morphology of the meniscus is independent of the inclination angle when absolute ethanol evaporates naturally. And the evaporation rate, heat flux and temperature distribution of meniscus at the initial stage of evaporation follow the law of resultant force distribution. That is, when the inclination angle is 60°, the evaporation rate and heat flux reach the maximum, i.e. 1.64 μm/s and 10.96 W/cm2, respectively, and the temperature between the center of the meniscus and the wedge region reaches 1.5 ℃. We used μ-PIV to observe the Marangoni vortex morphology of the vertical section of the meniscus, and found that there are different degrees of deformation at different inclination angles. When the inclination angle is 90°, the Marangoni vortex structure is destroyed.

A novel center-hybrid pin-fin microchannel heat sink with embedded secondary microchannels for hotspot thermal management

With the rapid advancement of microelectronics technology, the issue of excessive localized heat flux in electronic devices has become increasingly prominent. This study introduces a center-hybrid pin-fin microchannel heat sink (CHPFMHS) for hotspot thermal management, comprising a central hexagonal pin-fin region flanked by two lateral straight microchannel zones located at the inlet and outlet. Furthermore, four types of various secondary microchannels are integrated within the pin-fins of CHPFMHS (Case 1: with no secondary microchannel; Case 2–5: with 3-direction, 4-direction, 6-direction, and vertical intersecting secondary microchannels, respectively) for effective heat dissipation with low pressure drop. The performances of CHPFMHSs and non-hybrid straight microchannel heat sink (NHSMHS) are evaluated with Re = 50–400. For all flow rates, the pressure drops in Cases 2–5 are lower than that in Case 1, with Case 4 exhibiting the lowest pressure drop among all CHPFMHSs. The thermal resistance (Rth) and temperature non-uniformity (δT) of Case 5 with hotspot area (Ah) of 2.25 mm2 and pin-fin region length (Lrpf) of 3 mm are 47.3 % and 30.8 % lower than those of NHSMHS, respectively. Among Case 1–5, the configuration of Case 5 is the most optimal. The impacts of hotspot and the pin-fin region size of the CHPFMHS have also been investigated. As Ah rises to 6.25 mm2, in comparation with NHSMHS, Rth and δT of Case 5 decrease by 52.7 % and 40.2 %, respectively. As Lrpf rises, the values of both δT and Rth, for Case 5, approach their minimum when Lrpf is close to the length of the hotspot. However, they exhibit slight changes as Lrpf continues to increase.

Single-Walled Carbon Nanotube Based Field-Effect Transistors Functionalized with Odorant Receptors for Biosensing Applications

Bioelectronic detection of volatile organic compounds (VOC) has been demonstrated in a wide range of applications, with early reports focusing on environmental exogenous VOCs due to their adverse effects on human health; bacterial VOC signatures used as disease biomarkers, etc. Carbon nanotube field-effect transistors (CNT-FETs) are considered promising devices for bioelectronic detection due to their sensitivity, robustness and compatibility with microelectronic fabrication technologies. However, implementation of CNT-FETs still faces many challenges. Current VOCs detection approaches rely on separation techniques coupled with mass spectrometry, necessitating expensive equipment, labor-intensive preparation steps and trained personnel, and are not suitable for field use. Overcoming the challenges in the development of bioelectronic CNT-FET sensors holds great promise for high-throughput screening of VOCs.The natural insect odorant receptors (ORs) are highly attractive probes, potentially allowing ultrahigh specificity for VOC biosensing. Insect ORs exhibit remarkable sensitivities and the ability to selectively detect a vast number of VOCs. We have recently developed OR-functionalized carbon nanotube field-effect transistor (FET) devices. These FET devices comprise an isolated single-walled carbon nanotube (SWCNT), serving as the conducting channel material, functionalized with multiple insect ORs. These hybrid devices are capable of transducing ligand binding into an electronic current, without amplification. The insect OR-functionalized CNT FET were applied for the detection of several markers of environmental and clinical importance including Indole, Skatole, Octen-3-ol and Nonyl-aldehyde.We have developed a bioelectronic assay platform that contains a chip with 61 ORs-functionalized CNT-FET devices. Our unique functionalization method is based on directing the attachment of a native ORs-containing nanovesicles (which we have exogenously expressed and functionally characterized) to a generated CNT-FET point defect. Target binding-induced ionic current and conformational changes of ORs affect an electric field that modulates the device conductance.

Thermal Conductive Polymer Composites: Recent Progress and Applications.

As microelectronics technology advances towards miniaturization and higher integration, the imperative for developing high-performance thermal management materials has escalated. Thermal conductive polymer composites (TCPCs), which leverage the benefits of polymer matrices and the unique effects of nano-enhancers, are gaining focus as solutions to overheating due to their low density, ease of processing, and cost-effectiveness. However, these materials often face challenges such as thermal conductivities that are lower than expected, limiting their application in high-performance electronic devices. Despite these issues, TCPCs continue to demonstrate broad potential across various industrial sectors. This review comprehensively presents the progress in this field, detailing the mechanisms of thermal conductivity (TC) in these composites and discussing factors that influence thermal performance, such as the intrinsic properties of polymers, interfacial thermal resistance, and the thermal properties of fillers. Additionally, it categorizes and summarizes methods to enhance the TC of polymer composites. The review also highlights the applications of these materials in emerging areas such as flexible electronic devices, personal thermal management, and aerospace. Ultimately, by analyzing current challenges and opportunities, this review provides clear directions for future research and development.