bluuebunny/crossref_metadata_2025 huggingface dataset:
Vanadium/Water Electrolyser for Recharge of Vanadium Oxygen Fuel Cells
Authors: Noack Jens , Roznyatovskaya Nataliya , Menictas Chris , Skyllas-Kazacos Maria , Tübke Jens
Published: November 2022

The vanadium/oxygen fuel cell (VOFC) has evolved from developments to vanadium redox flow batteries (VRFB) for storage of renewable energy and perhaps for mobile applications. In VOFCs, oxygen is used to oxidise divalent vanadium ions to trivalent ions instead of the redox reactions of V(IV)/V(V) to achieve potentially higher energy densities and eliminate temperature stability problems associated with the energy storage medium compared to VRFBs. To charge a VOFC as an energy storage system, the discharge reactions have to be reversed with as few side reactions as possible. This process involves reducing trivalent vanadium ions to divalent vanadium ions through the application of electrical energy. The cathodic water generated during the discharge is used as the reductant. The water itself is oxidised to oxygen to keep the cycle between the charge and discharge processes as short and efficient as possible. This process is also exactly the reversal of the process which happens in VRFBs when atmospheric oxygen oxidizes divalent vanadium ions in vanadium electrolytes. As a synergistic effect, vanadium/water electrolysis can be also used to regenerate oxidized electrolytes and increase the life time of the batteries.

Using a cell with a commercial and iridium-based catalyst coated membrane, it was possible to fully reduce V3.5+ and V3+ solutions to V2+ with the formation of oxygen and with coulomb efficiencies of over 96%. The process was followed by introduction of an additional reference electrode to measure the redox potential of the electrolyte, the negative electrode potential and to calculate the positive redox potential. The cell achieved a maximum current density of 75 mA/cm2 during this process and was limited by the proximity of the V(III) reduction to the hydrogen evolution reaction. Due to the specific reaction mechanisms of V(IV) and V(III) ions, V(III) solutions were reduced with an energy efficiency of 61%, making this process nearly twice as energy efficient as the reduction of V(IV) to V(III). Polarisation curves and electrochemical impedance spectroscopy were used to further investigate the losses of halfcell reactions and to find ways of further increasing efficiency and performance levels.

Figure 1
(Edward G. Acheson Award) Exploration of Amorphous Thin Film Electronics
Authors: Kuo Yue
Published: November 2022

Thin films are critical elements in modern semiconductor devices. They are often prepared in the amorphous phase due to practical reasons, such as the reliability and manufacturability concerns. For example, the amorphous high-k gate dielectric is less prone to current leakage than the polycrystalline dielectric in the MOS device (1). The utilization of amorphous silicon (a-Si:H) or metal oxide semiconductor layer enables the commercial production of thin film transistor (TFT) arrays for flat panel displays (2). Requirements for amorphous thin films are related to the products. For advanced MOSFETs, the nanometer EOT gate dielectric is necessary (3). For LCD or OLED TVs or monitors, the fabrication process has to be low temperature, large area capability, and high throughput (4). In addition, the fabricated device has to be highly reliable, i.e., resistant to damages from subsequent process steps and environmental exposure.

In this talk, examples on amorphous thin films conducted in my group will be given and discussed. The doped metal oxide high-k thin film, which has a crystallization temperature higher than that of the undoped film (5), will be examined with respect to fundamental material and electrical properties. Novel devices made from this kind of film, e.g., nanocrystals embedded nonvolatile memories (6) and nano-resistor solid state incandescent LEDs (SSI-LEDs) (7), will be shown and the principles will be deliberated. Separately, PECVD process condition affects the a-Si:H TFT performance as well as the uniformity of the large-area material properties (8), which can be explained with the generalized deposition-etching mechanism (9). Applications of a-Si:H TFTs in nonvolatile memories, e.g., using the floating-gate structure (10), and protein/DNA analysis, e.g., attached with the microchannel device (11), will also be examined.

In order to achieve the best device performance with high reliability, both the bulk film and the interface properties of the amorphous thin film have to be tightly controlled, which requires the multidisciplinary approach. This is the early stage of the field. Many new and unique applications of the amorphous thin films can be expected in the near future.

Y. Kuo, ECS Trans., 54(1), 273-281 (2013).

Y. Kuo, Amorphous Silicon Thin Film Transistors, Kluwer, Norwell, MA, 2004.

J. Yan, Y. Kuo, and J. Lu, Electrochem. Solid-State Lett., 10(7), H199-H202 (2007).

Y. Kuo, ECS Interface, 22(1), 55-60 (2013).

J.-Y. Tewg, Y. Kuo, and J. Lu, Electrochem. Solid-State Lett., 8(1), G27-G29 (2005).

Y. Kuo, ECS Trans., 3(3), 253-263 (2006).

Y. Kuo and C.-C. Lin, Appl. Phys. Letts., 102(3), 031117 (2013).

Y. Kuo, J. Electrochem. Soc., 142, 186-190 (1995).

Y. Kuo, Appl. Phys. Lett., 63(2), 144-146 (1993).

Y. Kuo and H. Nominanda, Appl. Phys. Letts.,
89, 173503 (2006).

H. Lee and Y. Kuo, Electrochem. Solid-State Letts., 9, J21-J23 (2006).
Electrochemical Properties of MXene Electrodes in Aqueous Zinc Electrolytes
Authors: Matthews Kyle , VahidMohammadi Armin , Zhang Danzhen , Liu Liyuan , Simon Patrice , Gogotsi Yury
Published: November 2022

MXenes are a family of two-dimensional (2D) transition metal carbonitrides, with a general structure of M
n

+1X
n
T
x
, where M is the transition metal, X is carbon or nitrogen, T represents the surface terminations (F, O, OH), and n can vary from 1-4. MXenes have shown promise in multiple electrochemical systems including aqueous supercapacitors and non-aqueous batteries containing monovalent cations. However, there have been limited works studying the electrochemical properties of these materials in aqueous electrolytes with multivalent cations such as Zn2+ and Mg2+. MXenes have high (electro)chemical stability in halide zinc electrolyte systems unlike many oxide materials. Herein, the charge storage mechanism of Ti3C2T
x
was studied in multiple Zn containing aqueous electrolytes. In-situ XRD and in-situ UV-Vis were employed to monitor the intercalating species and redox response in the electrodes. Ti3C2T
x
electrodes could deliver battery-like performance at low rates with supercapacitor performance at high rates. This work demonstrates the potential of using MXenes in zinc ion capacitors and zinc hybrid energy storage devices.
(Invited) Status of Room-Temperature Mass-Production Capability Plasma-Based Copper Etch Process
Authors: Kuo Yue
Published: November 2022

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-ics

Kuo 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).
Effect of Oxide Thickness by Metallic Residue during Radical Oxidation Using Vertical Batch-Type Furnace Equipment on 300-Mm-Diameter Silicon Substrates
Authors: Lee Inkyum , Lee Inkyum
Published: November 2022

Metallic residues have a detrimental effects on device performance as well as retard gate oxide growth rate to induce unintended thinner oxide layer. In this study, we found that oxide thickness could be subjective to metallic residues on the edge of silicon substrate. Hydrogen-assisted radical oxidation was investigated using vertical batch-type furnace equipment for a 300-mm wafer fab. Radical oxidation has been used to improve gate oxide quality overcoming the disadvantages of conventional wet or dry thermal oxidation for some applications. Since the radical oxidation method reduces dangling bonds and defects in the oxide layer due to activated oxygen radicals, a high-quality oxide film can be formed. It also helps improve reliability due to reduced dependence on the silicon crystal direction of oxidation, enabling uniform membrane deposition of stress-focused corner rounding oxidation. In addition, it has excellent throughput as it is possible to process up to 100 wafers simultaneously. This study has shown that as the number of wafers with metallic residues in the dummy pattern on the edge due to the wafer edge exposure (WEE) difference for each photo step increases in the same batch for radical oxidation, the median thickness has decreased. When the silicon wafer with the metallic residue was included within the same batch of the furnace equipment, the thickness of the oxide layer was reduced by 1.8% compared to when the metallic residue-free silicon wafer was included. The radical oxygen have a tendency to react to tungsten rather than silicon, which reduces the O2 value required to form SiO2 and lowers the thickness, which is due to the difference in electronegativity between silicon and tungsten, 1.9 and 2.36 respectively. The study is expected to improve gate oxide quality by controlling metal residues on the wafer edge or backside during the fab process.
Additive Manufacture of Graphene Electrodes for Supercapacitor Applications
Authors: Reale Batista Mariana Desiree , Chandrasekaran Swetha , Moran Bryan , Salazar de Troya Miguel A , Carleton Adam , Roy Thomas , Zeng Manhao , Pinongcos Anica , Lin Dun , Wang Zhen , Hensleigh Ryan , Kuntz Joshua , Beck Victor A , Tortorelli Daniel , Stadermann Michael , Li Yat , Zheng Rayne , Zheng Rayne , Worsley Marcus Andre
Published: November 2022

Electrochemical energy storage devices, such as supercapacitors, are essential contributors to the implementation of sustainable energy. Supercapacitors exhibit fast charging/discharging ability and have attracted considerable attention within the automotive, aerospace, and telecommunication industries. Although these devices show great potential to meet power density metrics, they lack in terms of their energy density. To overcome this challenge, we are investigating better materials, architectures, and additive manufacturing techniques to print electrodes that increase the energy density while maintaining their high-power densities. Topology optimization was used to design an electrode with optimum performance. These electrodes were printed by projection micro stereolithography (PµSL) using PR48, a commercially available polymer resin. The printed electrodes were converted to carbon electrodes through pyrolysis at 1050 ֯C and characterized by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrical impedance spectroscopy. The performance of the PR48 optimized electrodes were compared against PR48 electrodes printed as a simple cubic lattice structure previously shown to improve capacitance and rate capability. The results show that our optimized electrodes have higher areal capacitances for all the current densities tested and they perform better in GCD and CV tests. Lastly, to increase the surface area of the electrodes and increase the capacitance further, we developed a resin formulation by combining graphene oxide (GO) into TMPTA polymer. Electrodes printed with 3%GO/TMPTA have improved electrochemical performance compared to PR48 as evidenced by their higher capacitances and their better GCD and CV curves. This work demonstrates the benefits of using topology optimization to design electrodes and materials development to improve the functional properties of 3D printable resins.

This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC

Figure 1
(Invited, Digital Presentation) Advanced Passivating Contacts for Silicon Photovoltaics
Authors: Matsui Takuya , Sai Hitoshi
Published: November 2022

Carrier selective passivating contacts, which provide dual functions of surface defect passivation and extracting one type of charge carriers, is a key enabler for high efficiency Si solar cells. Here we introduce two passivating contact materials developed in our lab: one is the hydrogenated nanocrystalline silicon (nc-Si:H) and the other is the metal-oxide (non-silicon) material. For the nc-Si:H, it is demonstrated that the use of the (p)nc-Si:H/(i)a-Si:H stack instead of the conventional (p)a-Si:H/(i)a-Si:H in silicon heterojunction solar cells provides not only a mitigation of the parasitic absorption loss but also improvements in passivation and electrical contact properties. This results in an efficiency increase by 0.3-0.6% absolute compared to our reference cell, and a best cell efficiency of 23.5%. For metal-oxide material, we have developed an atomic-layer-deposited titanium oxide (TiOx) that functions as an efficient and transparent hole-selective passivating contact without using buffer layer, leading to the proof-of-concept solar cells with efficiencies above 20%. An example of applying the developed contact material as a recombination junction layer of the perovskite/Si tandem solar cell will be presented.
(Digital Presentation) Selective Lead Recovery from a Mixture of Lead and Tin for Silicon Solar Module Recycling
Authors: Click Natalie , Tao Meng
Published: November 2022

During the recycling of solar modules, it is imperative to recover all the toxic lead used in solder. In this experiment, acetic acid is investigated for lead leaching and electrowinning from a mixture of lead and tin. 0.0636 g of tin powder (Alfa Aesar, 325 mesh, 99.8%) and 0.0372 g of lead powder (Alfa Aesar, 100 mesh, 99.95%, atomized) were combined with 30 mL of 0.01 M acetic acid (Sigma Aldrich) and 100 μL hydrogen peroxide (Alfa Aesar, ACS, 29-33% w/w). The solution was allowed to sit for 48 hours before electrowinning to allow the hydrogen peroxide to decompose. A copper working electrode, graphite counter electrode, and silver/silver chloride reference electrode were used in a three-electrode system.

A cyclic voltammogram shows lead reduction around –0.4 V vs Ag/AgCl, and a large stripping peak around –0.05 V. There is only one set of redox peaks in the graph, indicating only lead is reduced and oxidized. EDX confirms the presence of metallic lead on the working electrode after electrowinning at –0.6 V vs Ag/AgCl for 90 minutes. Only lead is present on the working electrode surface, no tin. These results show acetic acid to be a promising leachate for the electrowinning of metallic lead from silicon solar module solder waste.

Figure 1
(Invited) Opportunities and Challenges for GW Scale Perovskite PV Manufacturing
Authors: Yan Yanfa
Published: November 2022

Halide perovskite absorber materials offer a viable pathway for developing photovoltaic (PV) technology at GW levels because of their superior optoelectronic properties and low-temperature solution process ability. Despite the exciting progress and extraordinary potentials, the commercialization of this emerging technology still faces serious challenges. In this talk, I will discuss the opportunities and challenges for GW scale perovskite PV manufacturing.
(Invited, Digital Presentation) Carbon-Based Multi-Porous-Layered-Electrodes for Highly-Stable Perovskite Solar Cells for Space Application
Authors: Ito Seigo , Sakai Youichirou , Tsuji Ryuki , Shioki Takaya
Published: November 2022

Organo-lead halide perovskite solar cells (PSCs) have attracted the attention due to the high efficiency and the cost-effective manufacturing by printing system. However, PSCs have been unstable due to water from outside and iodide (I-) reacts with the back contact metal (Au or Ag) inside. To solve these two issues, porous-carbon-electrodes have been introduced in PSCs by a group of Hongwei Han. The MPLE-PSCs show very high stability: thermal stability at 100 ֩C over 4500 h in dark (by Univ. of Hyogo, Japan); damp-heat stability at 85 ֩C-85%RH over 3,000 h in dark (by Univ. of Hyogo and Kishu Giken Kogyo, Japan); light stability at 55 ֩C over 10,000 h (by EPFL, Switzerland). In this conference, we will show a challenging work of high thermal stability at 130 ֩C, which is required for outer space application.
Sputtered Niox Films As Hole Transport Layers for FA-Based Perovskite Solar Cell Application
Authors: Wang Lei , Yuan Shihao , Qian Feng , Chen Zhi David , Li Shibin
Published: November 2022

During the past years, the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has increased from 3.8% to 25.7%, making them the best candidate for the next-generation photovoltaic devices. Two dominant PSC architectures have evolved, a regular n-i-p structure with mesoscopic or planar heterojunction and an inverted p-i-n planar structure. Compared to the regular n-i-p PSCs, the inverted p-i-n PSCs possess the advantages of lower synthesis temperature, no hysteretic effect and good compatibility with the tandem solar cells. For p-i-n PSCs, the hole transport layer (HTL) determines the hole transport efficiency and crystallinity of perovskite, so it plays a crucial role in the stacked devices. The conventional organic HTL of PEDOT:PSS-based PSCs can achieve satisfying PCEs, but may be able to impede the commercialization of perovskite photovoltaic devices because of their high price and acidity-induced poor stability. By comparison, the inorganic P-type NiOx with wide band gap exhibits low cost, superior chemical stability and high hole mobility without corrosion to perovskite layer. Unlike the most reported spin-coated NiOx nanoparticle films, we used sputtered NiOx as HTL for application in FA-based PSCs and achieved a PCE of 20.05%. After systematically optimizing the sputtering parameters, including power, time and argon flow rate, we obtained better crystal quality, better transparency, proper energy level, and higher hole mobility of NiOx film. Reducing the interstitial vacancies and defects in NiOx films attributes to decreased nonradiative recombination losses, which mainly cause the hole accumulation near the perovskite/NiOx interface. Finally, a champion device with open-circuit voltage (Voc) of 1.09 V, current density (Jsc) of 23.4 mA/cm2, fill factor (FF) of 78% and PCE of 20.05% are obtained. This work has important significance for preparation of large-area perovskite solar cell modules.
Perovskite Films Passivated By the Organic Materials for High Efficiency and High Stability Devices
Authors: Dai Qilin , Qi Yifang , Zhang Qiqi
Published: November 2022

Perovskite films are attracting much attention due to their excellent optoelectronic properties. The corresponding photovoltaic devices show a record efficiency of 25.7% since 2009, which is very promising to surpass silicon solar cells. The defects of the perovskite films are the major negative factors to achieve high efficiency. The defects of the perovskite films are related to the polycrystal nature of the perovskite films, which is unavoided and caused by the solution-based method. Therefore, high-quality perovskite films with fewer defects are very critical to obtain high-efficiency devices. One strategy is to incorporate some additives into the perovskite solutions to adjust the perovskite film growth toward fewer defects. However, the additives are very limited in this strategy and limited success is reported. The promising strategy is to passivate defects of the films after the film fabrication. We present the passivation of perovskite films by organic materials including polymers, organic small molecules as well as dye molecules. The organic molecules with the special organic functional groups interact with perovskite films to modify the defects of the films to improve the charge transport and reduce charge recombination, leading to improved device performance. The surface defects and the grain boundary defects of the perovskite films are passivated by the organic materials, which is confirmed by the electron/hole only devices, electronic impedance spectroscopy (EIS) studies, photoluminescence, and time-resolved photoluminescence. The device efficiency increases from ~19% to ~21%, which is manifested by the J-V measurements. The passivation mechanism of the devices by organic materials is investigated and demonstrated.
Improving the Performance of Invert Perovskite Solar Cell Devices By a Multifunctional Ammonium Salt
Authors: Qi Yifang , Dai Qilin
Published: November 2022

In past years, halide perovskite solar cells (PSCs) have attracted much attention and are considered as the next-generation solar cells due to their excellent performance. Compared to the conventional structure, the inverted perovskite solar cell device has great potential in large-scale practical applications due to the low-temperature manufacturing process. However, the power conversion efficiency (PCE) is still lower than conventional structure devices, which is because of the high trap density in the surface and grain boundary of perovskite film. One kind of defect is the iodine vacancy caused by methylammonium iodide (MAI) volatilization during perovskite film annealing. I- could be oxidized into I2 and then volatilize out during the perovskite film annealing, the vacancy of I- could form trap states in the surface and grain boundary of the perovskite film. The surface traps induce many defects and increase the charge recombination rate in the inverted polycrystalline perovskite film, which causes PCE loss in the devices. Although lots of efforts are to improve the PCE of devices, perovskite solar cell device is still hard to practical applicate due to poor stability under light exposure conditions. Under light soaking especially UV light, perovskite film would degrade which means I3
- easily change to I2 and induce the lattice defects of perovskite film, which further influence the performance of PSCs. Herein, we present a strategy to suppress the I2 generation to decrease the trap density, reduce the charge recombination in perovskite film and further improve the performance of devices by an ammonium salt named tetrabutylammonium chloride (TBACl) modified. The PCE of devices increase from 18.52% to 20.36% after TBACl was modified, and TBACl also reduce the Voc loss in the perovskite solar cell devices. Furthermore, TBACl passivation enhances the light stability of devices and slows down PSCs degradation with UV light soaking. Because TBACl distributes in the surface and GBs of perovskite film that could absorb the UV light and decrease the effects on the perovskite layer. Benefiting from the influence of TBACl on perovskite solar cell devices, the devices could maintain over 90% with light soaking 120 h and UV light irradiation 450 min, respectively. However, the control devices only could maintain ~47% and ~51% of the initial PCE values under light exposure and UV light soaking conditions, respectively. Thus, we provide a low-cost, easy, and effective post-treatment strategy to enhance the device performance and improve the light stability of perovskite solar cell devices.
(Digital Presentation) Nitrogen-Doped Highly Porous Carbon from Polyaniline Nanotubes for Supercapacitors
Authors: Madhushani K.A.U. , Abeysinghe Arachchilage Prasadi , Lin Wang , Gupta Ram K.
Published: November 2022

The rapid development of clean energy generation devices has invaded every nook and corner of cutting-edge technology. With time, supercapacitors play a foremost role as a promising candidate in energy storage systems. However, electrode material becomes a decisive factor in the electrochemical performance of the supercapacitor and its capacitance can be controlled by using activated agents. Herein, the electrochemical window of the highly porous nitrogen-doped activated carbon was enhanced through the process of carbonization and activation of polyaniline nanotubes with KOH. Polyaniline nanotubes were synthesized using a facile oxidative polymerization process. Moreover, the changes in surface area and porosity were examined via BET analysis for the samples having polyaniline to KOH ratio 1:0.5, 1:1, and 1:2. It was observed that the surface area and pore volume from as-synthesized polyaniline to chemically treated samples was significantly improved from 18 to 3525 m2/g. The highest specific capacitance of 317 F/g was observed at the current density of 1A/g for polyaniline activated using 1:1 ratio of an activating agent. The sample achieved a maximum energy density of 36 Wh/kg with a power density of 455 W/kg. Further, these supercapacitors provided a good coulombic efficiency of about 100% with capacitance retention of 92% after 5000 charge-discharge cycles. The research suggests our facile approach to synthesizing nitrogen-doped carbon for supercapacitors could be adopted for commercial applications.
Fabrication and Characterization of Conductive FeCo@Au Nanowire Alloys for Semiconductor Connector
Authors: Kim In Yea , Lim Gi hwan , Kim Chae Yoon , Lee Min-Jeong , Kim Jaehun , Kim Dong Hyun , Lim Jae-Hong
Published: November 2022

A semiconductor test socket is one of the essential components for final electrical and performance testing of semiconductors. Due to the miniaturization of semiconductors, fine pinching of test sockets is required, so research on connectors for semiconductor inspection capable of fine processing is being actively conducted. The connector for semiconductor inspection consists of a powder coated with conductive powder on a magnetic material and rubber, and an electrical signal is transmitted through the conductive powder. A finer pitch rubber test socket shall maintain the electrical characteristics (resistance) at the same level, even though a smaller conductive path is formed as the gap between conductive paths narrows to respond to the increase in demand for fine pitch products.

Therefore, in this study, a technique for forming a conductive pathway between conductive powders to maintain the electrical properties of a semiconductor socket for fine pitch is introduced. In order to effectively improve a thin conductive path, a conductive nanowire was prepared to form a conductive pathway between conductive powders. Fig. 1 shows the schematic diagram for the fabrication of FeCo nanowires. FeCo nanowires were synthesized through electroplating using AAO (Anodic Aluminum Oxide) as a template, and Au as a conductive material was coated on the surface of FeCo wires through an electrochemical method to synthesize FeCo@Au. To uniformly coat Au on the surface of the FeCo wire during the coating process, sonication, vortex, and stay three methods were compared, as shown in Fig. 2. As a result of confirming the surface shape by SEM, the most uniform method was confirmed by the vortex method. In addition, the magnetic properties of FeCo@Au synthesized with a smooth surface were analyzed through VMS (Vibrating Sample Magnetometer). As a result, it can be confirmed that alignment through magnetism is possible. From these results, it was confirmed that the method of increasing the electrical conductivity by adding a wire to reduce resistance of semiconductor connector.

Figure 1
Initiated Chemical Vapor Deposited Anion-Conducting Solid-State Polymeric Electrolytes for All Solid-State Batteries: Impacts of Deposition Conditions and Polymer Composition on Performance Metrics
Authors: Ford Hunter , Chaloux Brian , Miller Joel , Klug Christopher , Long Jeffrey W. , Kim Youngchan , Jugdersuren Battogtokh , Liu Xiao , DeBlock Ryan H. , Johannes Michelle D. , Rolison Debra R. , Sassin Megan B.
Published: November 2022

Achieving both high energy and power density, two traditionally opposed battery metrics, requires moving away from the 200+ years-old 2D layered battery configuration to a three-dimensional all solid-state battery (3D SSB) configuration. The enhanced power and energy benefits bestowed by a 3D SSB design have been demonstrated in the Li-ion 3D SSB literature.1 However, due to limitations in thermal and electronic conductivity of Li-Ion active materials, 3D Li-ion SSBs are limited to microscale dimensions. A potential means around this limitation is to switch to conductive metal electrodes such as Zn and Ag, for which 3D architectures have been demonstrated.2 In such a case, the remaining roadblock to a macroscale 3D SSB is the submicron-thick solid-state electrolyte, which requires a non-line-of-sight deposition method for incorporation into the complex 3D base electrode. Initiated chemical vapor deposition (iCVD) is a non–line-of-sight method that is ideal for generating conformal polymer coatings on complex 3D architectures. We focus on polymers amenable to iCVD protocols that can be modified post-deposition to introduce anion conduction pathways that can facilitate Ag and Zn redox. Submicron-thick coatings of poly-dimethylaminomethylstyrene (pDMAMS) that are pinhole-free and electronically insulating on both 2D planar and complex 3D electrode architectures are prepared via iCVD. The pDMAMS coatings are rendered anion-conducting through a vapor-phase methylation process and subsequent ion exchange to yield desirable anion species (e.g., OH–, Br–, or HCO3
–). X-ray photoelectron spectroscopy, ATR-IR spectroscopy, and solid-state magic-angle spinning NMR spectroscopy confirm the structure of the pDMAMS film before and after quaternization, while atomic force microscopy and cyclic voltammetry with redox probes confirm conformality and absence of pinholes in the submicron film. With the use of cyclic voltammetry and AC electrochemical impedance spectroscopy, the electronic and ionic conductivities of the polymer films are measured before and after quaternization. Molecular dynamics simulations of pDMAMS as a function of anion and H2O content in the film are used to generate computational results (e.g., glass-transition temperature Tg, anion conductivity) for comparison to experimental results.

1. Long, J.W.; Dunn, B.; Rolison, D.R.; White, H.S. Chem. Rev. 2004, 104, 10, 4463–4492.

2. Parker, J.F.; Chervin, C.N.; Nelson, E.S.; Rolison, D.R.; Long, J.W. Energy Environ Sci. 2014, 7, 1117-1124.
(Student Award, 1st Place, Invited) Rapid Nanometer Scale Patterning Using New High-Sensitivity, Dry-Develop Resists
Authors: Engler Anthony , Schwartz Jared , Kohl Paul
Published: November 2022

A family of high-resolution, photo-thermal resists based on low ceiling temperature copolymers has been developed and used in a nanometer scale, direct-write thermal patterning tool. The polymer resists are composed of cyclic, low ceiling temperature (Tc) poly(aldehydes). Tc is the thermodynamic temperature which separates polymer from monomer. The Tc of the polymers is below room temperature making the polymer meta-stable at room temperature. The resists very rapidly and cleanly decompose into monomer only when triggered during patterning because the mechanism of depolymerization is suppressed. Cleaving a single bond in the polymer chain initiates the spontaneous and complete depolymerization of the polymer. The use of these low Tc polymers in thermal scanning probe lithography to resolve nanometer size features will be described. Laser ablation of the same polymers has been demonstrated in thermal scanning probe tools allowing for the rapid removal of large areas of the resist adding speed to the hot-tip thermal patterning capability. A particular advantage of the laser assisted thermal scanning probe patterning tools is the ability to form three-dimensional features both by hot-tip patterning and laser ablation.
Asymmetric Ba0.5Sr0.5Co0.8Fe0.2O3-Δ Membrane for Oxygen Permeation: Synergetic Fabrication By Magnetron Sputtering Deposition and Selective Laser Annealing
Authors: Mewafy Basma , Arias Serrano Blanca I. , Wallis Jan , Rohloff Martin , Silva Javier , Ravkina Olga , Kircheisen Robert , Kriegel Ralf , Wartmann Jens , Kruth Angela
Published: November 2022

The Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) mixed ionic electronic conductor (MIEC) is considered to be one of the most promising perovskite-based materials for oxygen transport exhibiting high oxygen permeability. Such oxygen-permeable perovskite membrane maybe applied to increase efficiency of combustion or reforming processes of new fuels such as green ammonia. An approach to elevate the oxygen permeability of BSCF membranes is reduction of membrane thickness, as the permeation process is mostly controlled by bulk diffusion. Since self-standing thin membranes are not sufficiently mechanically stable, asymmetric membranes consisting of a thin layer membrane deposited onto a porous bulk support are usually employed. . In this work, planar BSCF thin film membranes of 1 to 2 and 15 to 20 µm thickness were successfully synthesized by a combination of magnetron sputtering (MS) and thermal annealing (TA) and/or selective laser annealing (SLA) processes. Thin films appeared to be pinhole-free with a high crystallinity of a single perovskite phase and a microstructure that showed suitability for oxygen permeation applications. Correlations between thin film properties and MS process parameters (e.g. power, Ar/O2 ratio, pressure, etc.) and TA&/SLA parameters were established and optimised as key factors for producing thin film membrane exhibiting high oxygen flux and good stability. A variation of the oxygen flux through the BSCF asymmetric membrane as well as the porous substrate is presented as a function of temperature and also oxygen partial pressures applied to both sides of the membrane allowing for calculation of permeability of the deposited thin film.

Figure 1
Plasma-Assisted Anion Exchange Reactions in Thermally Grown Copper Oxide Nanowires
Authors: Kosicek Martin , Zavašnik Janez , Cvelbar Uros
Published: November 2022

Copper oxide nanowires represent a popular topic in recent research due to their potential use in gas sensors, batteries, supercapacitors etc. One of their advantages is facile synthesis, as they can be synthesized merely by heating metallic copper in the air. Moreover, their parameters, such as length and diameter, can be easily tailored by adjusting the conditions at which they are synthesized. Once obtained, nanowires can be further processed to enhance their properties. Common processing includes a partial or complete transformation of grown nanowires to another phase via cation or anion exchange. There are many existing methods for achieving such transformations, which are mostly solution-based. On the other hand, great unused potential lies in methods that exploit plasmas to achieve phase transformations in nanomaterials.

Even though there are a lot of reports on the synthesis of CuO nanowires, there are still a lot of knowledge gaps when it comes to their production and ion exchange reactions. In both cases, the challenges are associated with fundamental science behind processes during nanowire growth and phase transformations, as mechanisms behind NW growth and ion exchange reactions are not completely understood. In our present research, we tackle challenges connected to the thermal growth of CuO nanowires as well as the fundamental science behind phase transformations in them. In order to study mechanisms of nanowire growth, we performed thermal oxidation of copper to obtain nanowires at different times and temperatures. With detailed microstructural analysis of nanowires and oxide layers on which they grow as well as utilization of theoretical simulations, we obtained valuable information about growth of one dimensional metal oxide nanomaterials. Furthermore, mechanisms of anion exchange reactions were studied in the copper oxide – copper sulfide system. To achieve the oxide to sulfide transformations, copper oxide nanowires were subjected to plasma treatment with sulfur-containing gasses, which allowed us to study anion exchange in non-equilibrium plasma environments.
(Student Award, 2nd Place) Optical and Mechanical Properties of Europium-Doped Sicn Thin Films Prepared By Integrated Ecr-PECVD and Magnetron Sputtering
Authors: Azmi Fahmida , Ahammou Brahim , Bhattacharyya Paramita , Mascher Peter
Published: November 2022

Silicon carbonitride (SiCN) is a wide bandgap semiconductor material that has drawn significant interest over the past few decades due to its excellent optical, electrical, and mechanical properties[1]. Rare earth doping in wide bandgap semiconductors has several prospective applications in the field of photoelectric devices, solid-state lasers, flat panel displays, and high-energy radiation detectors [2]. Among the various rare earth materials, europium (Eu) is particularly interesting due to its optically active divalent and trivalent states capable of emitting in different visible spectral ranges [3].

In this work, Eu-doped SiCN thin films were prepared by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR-PECVD) with integrated magnetron sputtering [4] on p-type 3” Si (100) substrates. Silane (diluted in 90% argon), nitrogen (diluted in 90% argon) and ethane (C2H6) were used as precursor gases, and a 99.9% pure Eu sputtering target was used as a sputtering source. To understand the effect of C incorporation in the Eu-doped SiCN matrix, we have prepared a set of samples without C. The as-deposited samples were annealed over a wide range of temperatures from 600 to 1100° C in an internet N2 environment. Rutherford backscattering spectrometry (RBS) was performed to determine the atomic concentration of the constituents. Variable angle spectroscopic ellipsometry (VASE) analysis was performed to investigate the optical properties of the films. The room temperature photoluminescence (PL) experiments were carried out with a laser diode excitation source, operating at a wavelength of 375nm. Finally, we performed nanoindentation measurements to understand the deformation behavior of SiCN films as a function of the incorporation of C. The indentation hardness and Young’s modulus of the films were investigated for different Eu and C concentrations.

References:

[1] Q. Li, Y. Wang, X. Shan, X. Wang, and W. Zhao, “Preparation and optical properties of SiCN thin films deposited by reactive magnetron sputtering,” J. Mater. Sci. Mater. Electron., vol. 28, no. 9, pp. 6769–6781, 2017.

[2] Z. Ma, J. Zhou, Z. Chen, and E. Xie, “Luminescence properties of terbium-doped SiCN thin films by rf magnetron reactive sputtering,” Diam. Relat. Mater., vol. 20, no. 4, pp. 475–479, 2011.

[3] X. Zhang, D. Yang, D. Li, and M. Wang, “Intense photoluminescence from Eu-doped silicon-rich silicon oxide films prepared by electron beam evaporation,” IEEE Int. Conf. Gr. IV Photonics GFP, pp. 66–68, 2009.

[4] J. W. Miller, Z. Khatami, J. Wojcik, J. D. B. Bradley, and P. Mascher, “Integrated ECR-PECVD and magnetron sputtering system for rare-earth-doped Si-based materials,” Surf. Coatings Technol., vol. 336, pp. 99–105, 2018.
(Digital Presentation) Uniformity and Profile Improvement of Fin Etching Process at Wafer Extreme Edge for Finfet Mass Production
Authors: Song Jia , Ke Xing , Li Zhengning , Zhang En-Ning , Ji Shiliang , Zhao Zhenyang , Zheng Chongchong , Zhang Haiyang
Published: November 2022

The plasma sheath bending effect is widely observed in the wafer edge where the transition area to the edge ring is located. It is due to the electrical discontinuity and results in the difference in Ion Electron Angle Distribution (IEAD) between wafer extreme edge and inner wafer. As the aspect ratio increases during semiconductor scaling, the profile of etching is getting progressively sensitive to the sheath bending effect, resulting in a tilting profile or abnormal CD at the wafer's extreme edge. In our work, we presented a novel approach to improve the process capability to control the uniformity and profile during a two-step Fin etching process, where Fin hard mask (HM) etching and Fin etching are implemented: 1) Fin HM etching is applied in a capacitively-coupled plasmas (CCP) etcher by fine-tuning the focus ring temperature and the by-zone temperature module for local non-uniformity improvement, with a uniformity of Fin Critical Dimension (CD) improved by 60%; 2) Fin etching is applied in an inductively-coupled plasma (ICP) etcher by fine-tuning the movable edge ring to improve the sheath bending effect, with a profile and uniformity meeting targets. The improvement of the dry etching process at the extreme wafer edge will be discussed in detail.

Figure 1
(Invited, Digital Presentation) Formation of Nanostructures and Nanopores By Plasma Deposition and Etching Processes
Authors: Hegemann Dirk
Published: November 2022

Plasma processing represents an environmentally friendly, cost efficient and versatile method to modify materials surfaces at low temperatures. Plasma etching processes on polymers, for example, are well studied to enhance the adhesion of coatings and composite materials involving surface nanostructuring. Plasma sputtering is examined to deposit defective metal oxide coatings such as TiO2-x containing oxygen vacancies that are doped by another metal such as Ag. Plasma post-oxidation is applied to tune the nanostructuring of the dopant forming oxidized Ag islets strongly enhancing the catalytic properties to produce reactive oxygen species (ROS). Such coatings can even be functionalized by a plasma polymer cover layer. Non-toxic antimicrobial properties are thus enabled. Plasma polymer deposition with intermittent plasma etching is explored to produce highly nanoporous thin films. Preferential etching of residual hydrocarbons in SiOx layers induces interconnected nanopores in the growing film. Such films allow water diffusion and loading with hydrogels, e.g., as lubricants. Deposition of a nm-thick hydrophobic cover layer finally enables the control of water penetration yielding the nanoconfinement of water molecules that can form a dipolar field. The adsorption of bacteria was found to be affected by the resulting water structuring. Potential biomedical and other technical applications are discussed.
(Invited) Transport and Reaction Kinetics of Thermal ALE in High Aspect Ratio Hafnium Oxide Structures
Authors: Fischer Andreas , Mui David , Routzahn Aaron , Gasvoda Ryan J , Sims Jim , Lill Thorsten
Published: November 2022

Thermal atomic layer etching is rapidly becoming an important complementary processing technology in manufacturing 5 and 3 nm devices in the semiconductor industry. Critically, stacked chip architectures such as 3D NAND and 3D DRAM require conformal isotropic etching to remove material such as HfO2 in hard-to-reach locations with aspect ratios that can be >50. To achieve repeatable device performance throughout a 3D stack, the removal rate (etch per cycle) of the etched material during an etch process need to be controlled such that the overall etch is the same from top to bottom of the device stack. In this work, we have modelled the reaction kinetics and transport processes of reactants and by-products during a cyclical ligand exchange-based ALE process. This ALE process consists of two steps: a fluorination step, followed by a fluorine-to-chlorine ligand exchange-based removal step. Experimental data revealed that the fluorine dosing during the fluorination step was predominantly responsible for controlling the etch rate of the ALE process but had only a minimal impact on the etch profile inside these holes. The ligand exchange dosing, on the other hand, predominantly controlled the etch profile (depth loading) with equal etch rates top-to-bottom obtained when the step was operated close to saturation. Our model predicts, in agreement with the experiment, that adsorption and reaction rates during fluorination on HfO2 surfaces are significantly slower than transport times inside these deep holes leading to essentially flat fluorination profiles even if the fluorination step is not operated in saturation mode. In contrast, transport rates with the ligand exchange molecule are slow in comparison but adsorption and ligand exchange rates with the fluorinated hafnium appear to be significantly higher than for fluorine during the fluorination step. Slow transport in combination with high surface reaction rates for the ligand exchange step led to an etch rate that was dependent on aspect ratio (feature depth) in processes that used sub-saturation exposures.