bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Temperature Oxidation of Zircaloy-4 Under Conditions Simulating a Loss of Cooling Accident in Spent Fuel Pools Examined with Raman Imaging and 18O Tracer Techniques
Authors: Kasperski Anne , Guérain Mathieu , Gestin Mathilde , Duriez Christian , Mermoux Michel 
Published: February 2020

Since the Fukushima accident, an increased attention is continuously paid to the vulnerability of the Spent Fuel Pools (SFPs). In SFPs, for different reasons, degradation of the fuel rods induced by oxidation in air-steam mixtures after dewatering is a major safety concern: (i) the cladding material is the only barrier left against fission product dissemination, (ii) the heat released by the oxidation reactions can overcome the residual decay heat of the fuel and may become the main driving force to the accident escalation, (iii) hydrogen production is a strong concern because of the presence of steam, (iv) presence of air in the atmosphere is known to be an aggravating factor because of the “catalytic” role of nitrogen on the oxidation mechanism.
In this study, high temperature oxidation tests in oxygen, air and air - steam atmospheres were performed with Zircaloy-4 cladding tubes and plates specimens. Because spent fuels are concerned, the presence of the corrosion oxide scale formed in reactor during in-service operation was also considered. The tests described in this study were restricted to the 700 – 950°C range, and mostly performed at 850°C. Raman imaging was used to examine the specimens after the oxidation tests, either directly at the oxide surface, or on metallographic preparations for cross-section examinations.
We first used new opportunities given by Raman imaging to analyze, at least qualitatively, the structural and mechanical phenomena involved in this particular corrosion phenomena. Indeed, this method can provide information on the nature of phases that are present in the scale and on the stress level with sub-micron spatial resolution. The different methods used to extract this information that is present in the Raman data will be described and discussed.
Moreover, isotopic substitution was also considered. Actually, Raman spectroscopy has also the ability to quantitatively extract the 18O distribution in a zirconia oxide scale after a two stage experiment with a fair accuracy. Raman imaging gave clear evidence for different characteristic distributions of 18O in the scales. Some of them have been correlated with the development of cracks and porosity in the oxide which allows the corroding medium to penetrate locally in the scales. Nitrogen appears to have no or limited influence on the oxygen diffusion, but is observed to reach the metal/oxide interface much faster than oxygen. Thus, we also emphasize the potential of this method to investigate the 18O distribution in such complex corrosion scales.
Comparative Study of Chloride and Fluoride Induced Al Pad Corrosion in Wire Bonded Packaging Assembly
Authors: Issac Goutham , Lambert Alexander , Asokan Muthappan , Yi William , Chyan Oliver 
Published: February 2020

Microelectronics are used in virtually all electronic equipment’s nowadays ranging from medical instruments, automobiles, computers, cell phones and home appliances. Wirebonding process which connects the chip to the lead frame in IC packaging plays a very important role in the commercial production of IC’s. Chip usually consists of Al bond pads with Cu/Au wires. Thin film Al bond pads are easily vulnerable to corrosion in presence of contaminants and moisture. Bond pad corrosion is one of the common modes of corrosion failure in wire-bonded devices IC packaging. Improper rinsing, packaging and passivation defects allows moisture and contaminants into bondpads resulting in severe corrosion. Most common source of this corrosion comes from the presence of halide ions contamination as (Cl-, F-, Br- etc.) However, the corrosion morphology and the severity varies from different ions contamination as the chemistry governing the corrosion differs from one ion to another.
Our research is focused on key findings on corrosion of Aluminum bond pad due to chloride (Cl-) and fluoride (F-) contamination. Our central motivation is to identify this F- corrosion mechanism, so that it will help to develop a strategy to prevent it and study the comparison between Cl- and F- Corrosion using Micro-pattern corrosion screening technique, Wire-bonded device (WBD) and other characterization technique such as GC-MS, SEM and tafel. GC-MS reveals that H2 gas evolution is observed during Cl- corrosion of the WBD, whereas little or no H2 evolution is observed during F- corrosion. SEM and EDX reveals no presence of Cl- in the corroded areas of its corrosion, whereas strong F- signal is observed in F- corrosion of the bondpads revealing, that the corrosion products formed on the surface has very poor solubility showing that Cl- and F- has a complete different corrosion morphology. Striking contrasts in corrosion morphology observed during the Cl- and F- corrosion were explained in the present work and will lead to better understanding of factors influencing the bond pad corrosion leading to the wire bond failure in IC packaging devices. [Fig. 1]

Figure 1
Mechanistic Understanding of the Planarization Behavior of Low κ Organosilicate Glass Films with Beol Barrier Slurries
Authors: Mallikarjunan Anupama , Achtyl Jennifer , Yang Rung-Je , Huang Chen-Yuan , Chao Shih-Hsuan , Gan Lu , Ridgeway Robert , Schlueter James , Tsai Ming-Shih , Li Chris , O'Neill Mark 
Published: February 2020

Low κ Organosilicate Glass (OSG) films are being proliferated into new IC device architectures with CMP requirements spanning a wide range (highly selective to non-selective, low polish rates to high polish rates). This study aims to understand the relationship between these OSG film properties (both bulk and surface) and their planarization response, especially removal rate (RR). Eight OSG films were polished along with TEOS oxide using two barrier slurries. The films ranged in carbon content from 8 to 24 % and in nanoindentation elastic modulus from 5.5 to 21.8 GPa. Counterintuitively, higher mechanical strength (i.e., hardness, elastic modulus) of the low κ film did not result in lower polish rates; but was in agreement with previously noted behavior [1]. Removal rates also did not correlate to key OSG film properties such as refractive index (RI), dielectric constant (κ), or total carbon content (by X-ray photoelectron spectroscopy). However, an inverse relationship was observed between RR and the bulk chemical bonding structure (Si-CH3/Si-O ratio) as determined by transmission infrared spectroscopy (FT-IR) measurements (see Figure 1). In addition, a correlation between RR and OSG film’s surface free energy post-polish (measured from water and diiodomethane contact angles) was also observed. Based on the above findings, a mechanistic understanding of low κ OSG polishing was developed.
[1] L. Matz, M. Haas, M. O’Neill, R. Sawayda, A. Meyers, in Advanced Metallization Conference (AMC) (eds A. J. McKerrow, Y. Shacham-Diamand, S. Shingubara and Y. Shimogaki), Materials Research Society, Warrandale, PA, 463 (2009)

Figure 1
Performance of Trizact™ Microreplicated Pad in W Buff Marathon Process
Authors: Simpson Alexander W , Stomberg Jaimie , Muradian David , LeHuu Duy , Loesch Chris , Laraia Vince 
Published: February 2020

This work demonstrates the performance of a microreplicated pad used in a W buff polish process. 3M™ Trizact™ microreplicated pads consist of matrix designed asperitity and pore structures that can be tuned independently, into a wide variety of complex 3D structures. More uniform pad asperity diameter and height control allows for better wafer-pad contact interacions. Consequently, microreplicated pads have significantly higher contact area with the wafer surface compared to industry standard hard and soft pads. The unique heringbone groove design allows for efficient slurry transportation and uniform slurry flow distribution – enabling the potential for slurry saving and cost of ownership reduction.
The CMP wafer polish results show stable oxide RR (se Figure 1) and consistent W:Ox film selectivity over 3000 wafers. Wafer removal rate recovey was repeatablly fast following periods of wet idle. Stable uniformity/edge profile control were also achieved. Total defect counts were controlled and consistent throughout the duration of the 3000 wafer marathon run. Upon completion of the marathon run, the loss in pad asperity height loss was less than 3 microns (14 %) compared to initial asperity height illustrating the potential to extend the pad life significantly beyond 3000 wafers (see Figure 2). The results illustrate the benefit of micro-replicated asperities in CMP pads, These results are important because of the potential to improve pad performance and reduce the cost of CMP.

Figure 1
(Invited) Cobalt Damascene Chemistry for Advanced Interconnect
Authors: Najjar Elie , Sun Shaopeng 
Published: February 2020

In recent years, cobalt has caught more and more attention as an alternative material to Cu as the material for interconnect in advanced semiconductor technology. For electronic devices, the desire of reduction in size, but increase in performance, has driven the development of the process of interconnect toward a direction that the feature size of interconnects becomes smaller, so more components can be integrated in a more limited area on electronics. As feature size shrinking, cobalt brings benefits over copper as the material of interconnects1: 1) cobalt can have less resistance as there can be less electron scattering than is seen with copper, 2) and cobalt is less mobile than copper thus reducing electromigration. Electrodeposition is well known for its low cost of ownership as a metallization process. To achieve void-free and seam-free fill by electrodeposition for a feature less than 10nm, a bottom-up fill is required, and it is one of most challenging process among modern semiconductor technology. Filling a feature, usually a trench or via, via bottom-up fill means that the metallization grows predominately from bottom.
MacDermid Enthone has developed a Co chemistry which can provide void-free and seam-free fill to feature < 10nm. Also, it can achieve leveled overburden with good uniformity. In Fig 1., it is a FIB/TEM image of a feature, post-seed opening ~8nm and A/R of ~10, filled by MacDermid Enthone Co chemistry. In this report, a proposed electrochemical bottom-up fill mechanism will be discussed to reveal the challenge of cobalt damascene for advanced interconnect, and how they are overcome by the latest MacDermid Enthone Co chemistry
Figure 1: FIB/STEM of a feature filled by MacDermid Enthone Co chemistry

References

J. Jezewski, J. S. Clarke, T. K. Indukuri, F. Gstrein and D. J. Zierath, US 2014/0183738A1 (2012)

Figure 1
Ag Membranes for Electrochemical CO2 to CO Conversion in an MEA Type Set-up
Authors: Seger Brian , Larrazabal Gaston , Strøm-Hansen Patrick , Heli Jens Peter , Therkildsen Kasper 
Published: February 2020

While there has been a large push towards electrochemically derived fuels such as hydrogen, chemicals such as carbon monoxide have much more favorable economics(1) and are thus highly promising. Both Au and Ag are well-established catalysts for electrochemically producing CO,(2) but studies on upscaling these reactions to industrial relevant currents (> 100 mA/cm2) is lacking.
This talk will discuss our work on using Ag membranes for electrochemical CO2 to CO conversion in a membrane electrode assembly (MEA) device. The cathode is completely carbon free and can produce predominantly CO at currents up to 250 mA/cm2 (@ approximately 3 V), and thereafter significant H2 evolution starts to occur. Typical tests were 24 hours, but some longer-term data will be show, demonstrating the stability of the system. Variations in humidity from the gaseous cathode side had effects on both performance and durability. The anode electrolyte was a bicarbonate solution with either an accompanying K, Na, or Cs cation. Variations in the cations resulted in a notable performance change even though an anion exchange membrane was present. By inserting a reference electrode into our anode side we could separate our cathodic, anodic, and ionic losses, thus allowing us to better understand our system. The advantages, disadvantages, and engineering knowledge gained from this work will be summarized.
1) Progress and Perspectives of Electrochemical CO2 Reduction on Copper in Aqueous Electrolyte. Nitopi et al., submitted 2018,
2) Electrocatalytic process of CO selectivity in electrochemical reduction of CO2 at metal electrodes in aqueous media. Hori et al., Electrochimica Acta, 1994, 39, 11-12, 1833-1839
Nitrate Combustion Synthesis of NVP-Type Cathode Material for Na-Ion Batteries
Authors: Väli Ronald , Jänes Alar , Lust Enn 
Published: February 2020

The synthesis and characterization of a Na3V2(PO4)3 cathode material for room-temperature sodium-ion battery is reported. The NVP material was prepared using a two-step process which proceeded via sol-gel nitrate combustion method for precursor preparation and subsequent pyrolysis under Argon.
The materials have been investigated using SEM, EDX, XRD and TOF-SIMS methods. Electrochemical characterization has been carried out using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge method (GCD).
The electrode slurry was prepared by mixing the active material, conductive additive (Super P) and polyvinylidene difluoride (PVdF) binder in a 75:15:10 mass ratio. The mixed slurry was cast onto aluminium foil using doctor-blade technique. The cast electrodes were dried under vacuum for 24h. Electrochemical tests were carried out in coin cells, which were assembled in an Argon-filled glovebox (O2 < 0.1 ppm, H2O < 0.1 ppm). Sodium metal was used as the counter electrode and 1M NaPF6 in EC:PC (1:1 vol) as the electrolyte in half-cell measurements.

Acknowledgements

The present study was supported by European Regional Development Fund (Centres of Excellence TK141 (2014-2020.4.01.15-0011)6, Higher education specialization stipends in smart specialization growth areas 2014-2020.4.02.16-0026), “Institutional development program for research and development and higher education institutions” (ASTRA) (Graduate School of Functional Materials and Technologies, Materials Technology Projects SLOKT12180T and SLOKT12181T, Energy Technology Project SLOKT10209T), Estonian Research Council (Institutional Research Grant IUT20–13 and by NAMUR project 3.2.0304.12-0397. Mr. Väli thanks Estonian Students Fund in USA for financial support.
Effects of a Novel Fluorinated Linear Carbonate Additive on the High Voltage Performance of Lithium Ion Batteries
Authors: Dzakpasu Cyril Bubu , Roh Youngjoon , Byun Seoungwoo , Kim Ju Young , Kim Kwang Man , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

Lithium ion batteries (LIBs) are considered as suitable power sources for a variety of applications such as portable electronic devices and electric vehicles owing to their high energy density and long cycle life. To improve the energy density of LIBs, electrode materials with high reversible capacities; cathode materials that operate at high voltages and anode materials with low working potentials close to 0V vs. Li/Li+ have been developed. However, deterioration of the electrode-electrolyte interface causes unsatisfactory performance of batteries. Various approaches such as surface coating of electrode materials and the use of electrolyte additives have been proposed to stabilize the electrode-electrolyte interface. The use of reducible and oxidizable compounds for the formation of an artificial solid electrolyte interphase is one of the most effective strategies to improve the interfacial stability of electrodes.
In this study, we evaluate the performance of a novel fluorinated linear carbonate as an additive with LiNi0.8Co0.1Mn0.1O2 half-cells under high voltage conditions. The effect of the additive was characterized by linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and ex situ X-ray photoelectron spectroscopy (XPS). Overall, the additive was found to show an improvement in the cell performance.
In-Depth Analysis of Binder Distribution within Lithium-Ion Battery Electrode Using SAICAS
Authors: Byun Seoungwoo , Kim Kyuman , Choi Jaecheol , Ryou Myung-Hyun , Lee YongMin 
Published: February 2020

Microstructure and mechanical properties of lithium-ion battery (LIB) electrodes become more important as their loading levels increase highly for acheiving high energy density. In this point of view, we should control polymeric binder materials as well as nano-sized conductive materials within LIB electrodes. However, due to the limitation of appropriate analysis tools, it remains one of the challenging issues in LIBs. Fortunately, we have started using a new analysis tool, surface and interfacial cutting analysis system (SAICAS, Daipla Witnes, Japan), to measure adhesion properties of LIB composite electrodes as a function of depths. Based on the general principle, the adhesion strength is approximately propotional to the binder content, the polymeric binder distribution within the electrodes can be unveiled with a SAICAS.
In this study, we prepared two LiCoO2 electrodes dried at totally different temperatures, 130 and 230oC, and used to confirm the feasibility to figure out the polymeric binder distribution in the electrode by using SAICAS. First, the adhesion strengths of those electrodes were deliberately measured at every 10 μm depth from the electrode surface as shown in Figure. Simultaneously, not only surface and cross-sectional SEM images but also corresponding EDS atomic mapping were checked to find correlation with adhesion strength. The electrochemical properties such as DC-IR, rate capability, and cycle life at room and high temperatures were also investigated.
Interconnected Porous Sb-C Nanocomposite As an Anode Material with High Capacity for K-Ion Batteries
Authors: Ki Hyeong-Seo , Verma Rakesh , Park Chan-Jin 
Published: February 2020

With growing demand for clean and sustainable energy resources, lithium-ion batteries (LIBs) have been intensively developed and considered as one of the most successful energy storage devices in the past decades. However, the growth of LIBs has been restricted due to unevenly distributed and limited lithium natural resources. Therefore, numerous efforts have been devoted to finding the alternatives to LIBs such as sodium-ion batteries (SIBs) and potassium ion batteries (PIBs) due to their benefits of abundance and low cost resources. Moreover, redox potential of K+/K (-2.93 V vs. SHE) is lower than Na+/Na (-2.71 V vs. SHE), which indicates higher cell potential and energy density compared with that of SIBs. Recently, alloy type antimony (Sb) anode has attracted considerable attention as a promising anode materials for PIBs owing to its low and suitable potassiation potential for alloying/dealloying and high specific capacity corresponding to K3Sb phase. However, the large volumetric change during repetitive cycling may lead to pulverization of the active material and resultant rapid capacity fading. To address the issues, many strategies have been suggested such as nano-sized particles, porous structures, and embedding active materials into carbon layer thereby improving the cyclability of Sb-based anodes.
In this study, the interconnected porous Sb-carbon nanocomposite (Sb-C) was synthesized through simple citrate gel carbothermal reduction route with citric acid as a chealating agent and carbon source as well. The gel complex was calcined at different temperatures in N2 atmosphere for the carbothermal reduction affecting porosity of the Sb-C composites. The crystal structure, morphology and carbon content of the Sb-C composite were investigated by XRD, SEM, and TGA. Effect of the calcination temperature on the electrochemical performance of the Sb-C composite was investigated within a potential range from 0.01 V to 2.5 V vs. K/K+. The interconnected porous Sb-C nanocomposite exhibited the excellent electrochemical performance suitable as an anode material for PIBs.
Carbon Coated Tin Selenide Nanocomposite Anode Materials for Advanced Potassium-Ion Batteries
Authors: Verma Rakesh , Park Chan-Jin 
Published: February 2020

Energy storage systems with high capacity and low cost are of primary concern in the development of electric vehicles and smart grids. Recently, room temperature potassium-ion batteries (PIBs), which possess the advantages of high theoretical capacity and the abundant earth reserves and low prices of K, becomes an attractive alternative to the conventional lithium-ion batteries (LIBs). Current efforts have focused on developing new alloy type materials to replace the existing carbonaceous based anode materials for PIBs because of the high theoretical specific capacity of the alloy type anodes. In particular, SnSe is a potential candidate anode material for PIBs due to the earth-abundance, environmental friendly, and chemically stableness. However, the SnSe can suffer from a poor cyclic performance and rate capability, which are mainly attributed to the large volume change during potassiation/depotassiation and the relatively low conductivity of SnSe, respectively.
In the present work, to address the issues related to SnSe, SnSe/C nanocomposite was prepared through a simple and low-cost high energy ball milling technique. The phase purity, morphology, and structure of the prepared materials were characterized by XRD, BET, Raman spectroscopy, SEM, and TEM. Further, when this SnSe/C nanocomposite was tested as an anode material for PIBs, it exhibited a good cycling performance and excellent rate capability. The good cycling performance and excellent rate capability could be ascribed to the well dispersion of SnSe within the SnSe/C nanocomposite, which enhanced the electrical conductivity and electrochemical kinetics of the whole anode material. Furthermore, the Super P carbon also acted as a buffer material to accommodate the huge volume change of SnSe particles during potassiation/depotassiation processes. Furthermore, the effect of the alloying/dealloying process on the crystal structure of SnSe/C was examined by the ex-situ XRD patterns recorded in various stages of discharge and charge. The potassiation/depotassiation mechanism was suggested.