bluuebunny/crossref_metadata_2025_split huggingface dataset:
3-Mercapto-1-Propanesulfonate for Cu Electrodeposition Studied By in Situ Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy (SHINERS)
Authors: Schmitt Kevin Gary , Schmidt Ralf , von Horsten Frank , Vazhenin Grigory , Gewirth Andrew A. 
Published: February 2020

Damascene processing of copper interconnects for integrated circuits requires void-free filling of high aspect ratio trenches and vias. A combination of organic additives is commonly used to achieve bottom-up or superfilling of these features by electrochemical plating. To better understand the surface interactions of brightening agents, 3-mercapto-1-propanesulfonate (MPS) was studied by in situ shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). The influence of each functional group was discerned by individually testing butanethiol and butanesulfonate as model compounds. In an acidic solution of copper sulfate, MPS coadsorbs with sulfate. Butanethiol displays similar adsorption behavior, but butanesulfonate demonstrates no Raman bands attributed to surface adsorption. This strongly suggests that the sulfonate moiety does not interact significantly with the Cu substrate, and MPS adsorption occurs through the thiol linkage. When chloride is added, sulfate is displaced and both MPS and butanethiol coadsorb with the halide. However, the Cu-Cl stretching vibration is weaker in the presence of these additives than it is with Cl- alone. In addition to spectroelectrochemical experiments, Cu deposition processes with these additives were also monitored by electrochemical quartz crystal microbalance measurements. Butanethiol is more resistant than MPS to both Cu deposition and stripping, which confirms that the sulfonate group plays an important role in facilitating Cu deposition.
Theory of Co-Adsorption and Its Application to Copper Superfilling
Authors: Liske Romy , Krause Robert , Uhlig Benjamin , Gerlich Lukas , Bott Sascha , Wislicenus Marcus , Preusse Axel 
Published: February 2020

The advanced scaling in microelectronic devices requires filling of smaller and smaller copper lines without the introduction of voids and defects. Electrochemical deposition is the process of choice as it ensures a bottom-up, void-free copper growth, so-called superfilling. The present work focuses on the mechanism of superfilling based on additive co-adsorption principles. These principles describe the formation of a complex and reversible adsorption layer of two interacting surface active substances [1]. While positive interaction causes enhanced adsorption and increased surface coverage, negative interaction results in inhibited adsorption and lower surface coverage (Figure 1). The co-adsorption theory is adopted to explain the functioning of plating additives which is presumed to be the key for superfilling. Electrochemical measurements and partial fill experiments under production-like conditions are carried out to study the effects of bath additives in sub-100 nm structures. It is shown that superfilling is a result of the synergetic adsorption behavior of two organic additives, accelerator and suppressor, and a balancing between additive accumulation and copper deposition rate. During copper deposition both additives accelerator and suppressor accumulate near the growing surface. Due to diffusion limitations inside narrow features, a higher additive concentration evolves compared to blank surface areas. If the deposition proceeds at a high rate, the different additive concentrations inside and outside small features can be used to achieve superfilling (Figure 2).

References

[1] B. B. Damaskin, V. A. Safonov, O. A. Baturina, and N. V. Safonov, J. Electroanal. Chem., 550–551, 3 (2003).

Figure 1
Using Graphene As a Conducting Layer and Barrier Layer for High Aspect Ratio through Silicon Via Filling
Authors: Zeng Wei-Yang , Chang Shih-Cheng , Dow Wei-Ping 
Published: February 2020

Traditional process for TSV fabrication is a dry process that includes the following step: (1) formation of vias by reactive ion etching; (2) formation of a SiO2 isolation liner; (3) deposition of a TiN barrier layer and a copper seed layer; (4) via fill with copper electrodepositing. Herein, we attempt to use graphene to substitute the TiN barrier layer and the copper seed layer for reducing the traditional process procedure.
Graphene materials, including single layer and multi-layer graphene platelet, have recently drawn extensive attention due to their outstanding electrical and thermal properties. Reduction of graphene oxide (GO) is a method to prepare the graphene film. Since GO has a large amount of oxygen functional groups, it can be well dispersed in several solvents and enable it to be coated on a substrate by a chemical grafting method using a wet process.

In TSV technology, the thermo-mechanical fatigue may lead to failure in the TSV interconnects because the coefficient of thermal expansion (CTE) of copper is much higher than that of silicon. The packaging materials with different CTEs will induce large stresses at interfaces. To overcome this problem, we choose graphene sheets to substitute the copper seed layer since the CTE of graphene is closer to silicon than copper. In our research, we reduce the procedure of TSV fabrication using a wet process to simultaneously substitute barrier and seed layer with graphene, and to replace filled copper with filled nickel-tungsten alloy in high aspect ratio TSV. This replacement can result in lower fabrication cost compared with the traditional TSV process.
Surfactant-Templated Nanoporous Metal Films and Powders
Authors: Robinson David B. , Cappillino Patrick J. , Jones Christopher G. , Hekmaty Michelle A. , Kent Michael S. , Jacobs Benjamin W. , Hjelm Rex , Parent Lucas R. , Arslan Ilke 
Published: February 2020

At sufficiently high concentrations, many surfactants can direct electrodeposited or chemically reduced metals to form nanoporous structures. The surfactants can be small molecules, block copolymers, or polymers with functional endgroups. Under some conditions, the pores exhibit uniform, tunable sizes and long-range ordering. We will present a brief overview of demonstrations of these phenomena from the literature, and then focus on our own efforts to produce and characterize various forms of nanoporous palladium, a material of interest for energy storage, hydrogen storage, gas separation and sensing, and catalysis applications.
We have used liquid-cell transmission electron microscopy and small-angle neutron scattering to study the mechanisms of particle growth in the presence of surfactants. Our results suggest that Pd nanoparticles form and sinter around micelles present in the aqueous phase. Changing the size of the surfactant molecules affects the size of these micelles, and ultimately determines the pore dimensions. Careful control of surfactant self-assembly and particle growth conditions is required to obtain long-range order. However, porosity that is more disordered, but still of quite uniform size distribution, can be obtained under much more relaxed conditions, and lower surfactant concentrations. We believe that interactions between the surfactants and the metal surfaces are more influential in these cases. The flexible range of conditions under which surfactants are able to induce nanoporosity suggests that this technology could prove to be a valuable synthetic method for energy materials with high power densities, as well as chemical engineering materials with high surface reaction rates.
Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. The Lujan Neutron Scattering Center at LANSCE is funded by the DOE Office of Basic Energy Sciences and Los Alamos National Laboratory under DOE Contract DE-AC52-06NA25396. The work was funded in part by Sandia’s Laboratory-Directed Research and Development program.
Effect of Plating Additives on Microstructure and Properties of Electrodeposited Ni-Fe Alloy Thin Film
Authors: Hung Mao-Chun , Dow Wei-Ping 
Published: February 2020

With the evolving technology, the frame mounted design of electronic components has increasingly become high-density, which leads to the electronic elements that are inevitably vulnerable to electromagnetic interference and then affect other electronic products’ functions. The solution is to use well conductive material that operates the shielding process. The material includes metals and conductive polymers which are common sources of the protective materials in dealing with the main conductive surface. Although this masking method has been widely recognized, several problems are still observed in practice, including the vulnerability to scaling, abrasion, corrosion and process load.
In this study, we adopt Fe-Ni alloy film as the shielding material and manufacture it by electroplating. We intend to explore the effectiveness of changing the plating bath composition, plating parameter and plating additives on structural strength and magnetic properties of the Fe-Ni alloy film. Different proportions of nickel and iron ion concentration and content of H3BO3 cause different proportions of electrodeposited elements in the film. And the higher content of nickel ion will have higher permeability. In magnetic electroplating, plating additives play an important role. The findings suggest that various additives lead to different crystalline orientations, grain sizes, surface roughness. A strong correlation is also shown between the observed structural changes and the changes in the magnetic properties, such as permeability. Additionally, anti-corrosion is a significant issue. We can improve the corrosion problem by doping little element such as Boron in the film, obtain the corrosion potential and corrosion current by Tafel analysis. The ultimate goal of the study is to meet the requirements of electronic industry in manufacturing high permeability and optimum corrosion resistance for shielding material Fe-Ni alloy film.
Self-Terminated Electrodeposition Reactions
Authors: Moffat Thomas , Liu Yihua , Ahn Sang Hyun , Wang Rongyue , Gokcen Dincer , Hangarter Carlos , Bertocci Ugo 
Published: February 2020

In a recent publication Pt deposition at negative potentials revealed an unanticipated self-terminating characteristic that enables controlled deposition of Pt monolayer films from a K2PtCl4-NaCl electrolyte. In the case of Pt, the deposition reaction is quenched at potentials just negative of proton reduction by alteration of the double layer structure and adsorption properties induced by a saturated surface coverage of underpotential deposited hydrogen, (Hupd). The surface may be reactivated for Pt deposition by stepping the potential to more positive values where Hupd is oxidized and fresh sites for adsorption of PtCl4
2- become available. Periodic pulsing of the potential enables sequential deposition of additional Pt layers to fabricate films of desired thickness relevant to a range of advanced technologies in manner that is tantamount to wet atomic layer deposition (ALD). In the presence of iron group metal the Hupd induced suppression is lifted by underpotential deposition of the iron group metal as revealed in voltammetric studies of singular surfaces and thin film deposition studies of the binary Pt100-xNix and Pt100-xCox alloy. Bulk alloy formation is facilitated by ongoing Pt deposition that incorporates the iron group metal in accord with the excess enthalpy of alloy formation. This talk will present an update on the exploration of the generality of self-terminating deposition reaction to other chemical system.
Effect of Oxygen on Working Life of Additives and Improved Design of Anode Bag in Copper Electroplating
Authors: Hsu Chien-Hsing , Hsu Jia-Feng , Yuan Wei-Li 
Published: February 2020

The research studied the degrading and consuming phenomena of organic additives caused by oxygen generated by the insoluble anode in the process of copper electroplating. A double-layer anode bag was designed to prevent the additive ions from approaching the anode and getting degraded. Nitrogen bubbles of a particular size were injected into the anode bag gap to help capture dissolved oxygen molecules and merge with tiny oxygen bubbles coming from the anode. Therefore, the total surface area and number of oxygen bubbles were reduced, the oxygen concentration in the merged bubbles was diluted, and the amount of dissolved oxygen in the electrolyte was lowered. The improved design of anode bag with nitrogen purging slowed down the degrading rate and elongated the working life of the additives, and thereby cut down the production cost. In addition, a recycle system was designed to remove oxygen from nitrogen for reuse of nitrogen.
Effect of Tin Oxide Additive on the Suppression of Dendrite Growth of Zinc Electrodeposits
Authors: Kim Hong-Ik , Shin Heon-Cheol 
Published: February 2020

Unlike the market acceptance of Zn-air primary battery, the Zn-air secondary battery is not yet commercialized, mainly due to its poor cycling stability. Although a number of issues have been raised as possible reasons for its low electrical rechargeability, the dendrite growth of Zn during charging process might be most critical because it leads to short circuits and thereby catastrophic failure. Many inorganic additives have been reported for the suppression of the dendritic growth of Zn electrodeposits. For example, it is known that a small amount of Pb ions in an alkaline solution effectively suppresses the Zn dendritic growth. Nevertheless, the environmental issues of Pb-containing additive drive the researchers to search for its alternatives.
Sn is cost effective as well as environmentally friendly. Since it has higher reduction potential than Zn, it might be co-deposited with Zn to possibly change the growth habit of Zn dendrite. In fact, it has been reported that Sn ions affected the Zn deposition on a Zn single crystal at the very low Sn content, implying that Sn can be a possible option to toxic and expensive additives. In this work, we report that SnO additive significantly changes the morphology of Zn electrodeposits and suppresses quite well its dendritic growth. From the cyclic voltammograms at different SnO contents, it is proved that a few milli-moles of Sn ions in the electrolyte have a strong effect on the Sn deposition process. Moreover, the microscopic observation reveals that the non-uniform and dendritic growth of Zn electrodeposits is considerably suppressed at high content of SnO additive. From the depth profiling of the composition of Zn electrodeposit, it is confirmed that Sn is co-deposited with Zn during the course of deposition process, strongly indicating that the incorporated Sn interferes the dendritic growth of Zn. However, the addition of excess SnO resulted in a rough surface and crumbling porous particles containing large amount of Sn phase.
In this presentation, an optimal SnO content required for the creation of dense Zn electrodeposits will be highlighted. Moreover, the possible mechanism of dendrite growth suppression by Sn ions will be further discussed.
Understanding Capacitive Deionization Performance By Comparing Its Electrical Response with an Electrochemical Supercapacitor
Authors: Garcia - Quismondo Enrique , Santos Cleis , Palma Jesús , Anderson Marc Arlen 
Published: February 2020

Capacitive deionization (CDI) is an electrochemical water treatment process that allows one to purify saline water by removing ionic species while storing energy simultaneously. The key to CDI is the adsorption of charged particles (ions) in the electrical double layer (EDL) of an electrode upon polarization by a direct current (DC) power source, the same as charging an electrochemical supercapacitor [1][2]. However, there are some differentiating aspects between CDI and supercapacitors that must be considered before this technology can be commercially competitive [3].
When a supercapacitor is charged, energy used is influenced by different parameters such as the current intensity, the electrode capacitance, and also by the current intensity of the previous step (discharge). If the capacitor operates under ideal conditions (i.e, high conductor electrolyte, low resistance connections), the influence of these parameters is practically negligible. However, if the system works under non-ideal conditions (greater electrolyte resistance) as in a CDI system, the influence of these parameters in subsequent stages may be relevant when the current intensity during charging is different than that used in discharge.
Thus, a better understanding of the operational problems arising from the use of Supercapacitors is significantly important to aid their application as CDI in real-world devices including desalination, municipal drinking water, wastewater treatment and water-reuse projects [4].
In this work, a 310 Farads – 2.5 Volts supercapacitor cell and a CDI stack (70 Farads – 1.5 Volts) are tested under new operational cycling modes based on successively apply discharge rates with the same charge intensity, and similarly different charging rates over constant discharge intensity [5]. This approach allow to analyses comparatively the impact of applying charge and discharge at different rates on electrical performance (capacitance, resistance and round-trip energy efficiencies) of both technologies; supercapacitors and CDI.

References

[1] P.M. Biesheuvel, J. Colloid Interface Sci. 2009,332, 258-264.
[2] P.M. Biesheuvel, B. van Limpt, A. van der Wal, J. Phys. Chem. C
2009, 113, 5636-5640.
[3] M.A. Anderson, A.L. Cudero, J. Palma, Electrochimica Acta
2010, 55, 3845-3856.
[4] E. García-Quismondo, C. Santos, Jesús Palma, M. A. Anderson, Desalination and Water Treatment
2014, DOI: 10.1080/19443994.2014.984929. Accepted

[5] E. García-Quismondo, R. Gómez, F. Vaquero, A. López Cudero, J. Palma, M.A. Anderson,, Phys. Chem. Chem. Phys.
2013, 15 (20), 7648-7656.
Improving Electrosorption Performance in Membrane Assisted Capacitive Deionization Cells Using Asymmetric Electrodes Configuration
Authors: Omosebi Ayokunle , Gao Xin , Landon James , Liu Kunlei 
Published: February 2020

Capacitive deionization (CDI) is an emerging salt treatment technology that functions by concentrating ionized salt into porous electrodes with the aid of an applied electric field. Unlike some de-salting technologies like distillation or reverse osmosis that separate water from salt content with the aid of added heat or pressure, CDI electrostatically targets the salt content instead, and it is particularly attractive for the treatment of mid (brackish water) to low (tap water) concentration salt streams [1]. In addition, CDI offers the possibility of energy recovery in the convenient form of electricity which can be used to directly power subsequent CDI units, or other auxiliary devices. Membrane-assisted capacitive deionization (MCDI) is an improvement to conventional CDI whereby ion-exchange membranes (IEMs) are placed next to the porous carbon electrodes to increase desalination performance by mitigating losses that result from converting electronic to ionic charge at the electrode-electrolyte double layer.
During MCDI operation, electrode polarization results in the attraction of counter- ions (opposite in polarity to the charged surface), while co-ions (similar in polarity to the charged surface) are repelled away from the polarized surface [2]. The membranes used for the operation hinder the repulsion of co-ions back into the bulk, leading to an increased flux of counter-ions to balance the co-ions contained in the macropore space resulting in typically higher charge efficiencies over the CDI only system. In a departure from the traditional architecture which utilizes the same electrodes to form both the anode and cathode, MCDI systems can instead be asymmetrically assembled with ion-specific electrodes to increase specific charge excesses, and whereby any such specificity can be quantified via potential of zero charge (PZC) measurements.
In order to demonstrate benefits to deionization performance, we will present the electrosorption performance and charging characteristics of MCDI cells configured with pristine and nitric acid-treated Zorflex activated carbon electrodes with PZCs of -0.2 and 0.2 V vs SCE, respectively, based on differential capacitance measurements. Results from the asymmetric configuration will be compared to those from pristine anode-pristine cathode configurations to quantify the extent of variation in performance.

Acknowledgements

The authors are grateful to the U.S. - China Clean Energy Research Center, U.S. Department of Energy for project funding (No. DE-PI0000017), and thankful for the support of the State of Wyoming Advanced Conversion Technologies Task Force for their support.

References

[1] Y. Oren, Desalination 228 (2008) 10.
[2] E. Avraham, Y. Bouhadana, A. Soffer, D. Aurbach, J. Electrochem. Soc. 156 (2009) P95.
Graphite Anodes for Electroreduction of Uranium Oxide
Authors: Motsegood Perry , Willit James , Williamson Mark A. 
Published: February 2020

Recycling of used nuclear oxide fuel is under investigation using pyrochemical methods, which involve a series of molten salt processes performed at elevated temperatures and result in the separation of actinides from fission products. During this process, used fuel oxides are electrochemically reduced to metals prior to electrochemical separation of the actinides from fission products in a subsequent process step. This electroreduction is typically performed at 650°C in LiCl-Li2O. Reduction of UO2, the primary component of used nuclear fuel, has been successfully demonstrated at the kilogram-scale using platinum anodes1-2, but progression toward larger scales presents different requirements for anode materials.
Carbon (graphite) is commonly used in commercial molten salt processes within the ore refining industry. It is cost effective, readily available, and a logical choice for scale-up needs. However, different chemistries in molten LiCl-Li2O result from this change of anode material in both the salt and off-gas streams. Instead of forming oxygen at a platinum anode, the byproduct gas becomes CO and CO2. Although slightly soluble, these species can react with Li2O to form Li2CO3 as a result of residence time within the salt. The carbonate concentration can build up in the salt during the reduction process, which is problematic because of potential reaction between actinides and carbonate ions to form undesired byproducts in the reduced product.
This report will discuss use of carbon as an anode material for the electroreduction of UO2 to uranium metal in molten LiCl-Li2O at 650°C. We will present design challenges and a discussion of salt chemistry with respect to carbonate formation in the system, along with results on reduction efficiency.

References:

Laszlo Redey and Karthick Gourishankar, “Direct Electrochemical Reduction of Metal-Oxides” US Patent US6540902 B1, Granted April 1, 2003

S. D. Herrmann, S. X. Li, M. F. Simpson and S. Phongikaroon, Separation Science and Technology
2006, 41, 1965-1983.

The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. The U.S. Government retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government.