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This paper asserts that the development of continuum-scale mathematical models utilizing John Newman’s BAND subroutine can be simplified through the use of dual number automatic differentiation. This paper covers the salient features of the BAND algorithm as well as dual numbers and how they can be leveraged to algorithmically linearize systems of partial differential equations; these two concepts can be combined to produce accurate and computationally efficient models while significantly reducing the amount of personnel time necessary by eliminating the time-consuming process of equation linearization. As a result, this methodology facilitates more rapid model prototyping and establishes a more intuitive relationship between the numerical model and the differential equations. By utilizing an existing and validated programming module, dnadmod, these advantages are achieved without burdening the general user with significant additional programming overhead.

Three-dimensional (3D) configuration of high-performance energy storage devices has been the subject of ongoing investigations targeting their integration in autonomous microelectronic systems. In this study we demonstrate a route toward the realization of high capacity cathode material for 3D thin-film lithium-ion (Li-ion) batteries. Electrolytic manganese dioxide (EMD) film can be applied as a Li-ion intercalation electrode upon its conversion to lithium manganese dioxide (LiMn2O4 or LMO) by solid-state reaction. The main challenges of depositing thicker EMD film directly on the current collector often lay in achieving a good film adhesion and preventing oxidation of non-noble current collectors such as TiN, Ni. To improve the adhesion of the EMD films we modify the surface of the current collector by means of thin-film or seed layer coatings, which also prevent the oxidation of the underlying current collector substrate during the anodic deposition process. As a result submicron to micron thick EMD films with good adhesion were deposited on various current collectors. The acidity of the electrolyte solutions was varied depending on the type of the surface coating or current collector used. The mechanism of the EMD film growth and morphology on different substrates was examined. Compatibility of the proposed current collector interface modification for the electrodeposition of conformal thick EMD films on high-aspect ratio microstructures was demonstrated. A method of EMD film conversion to LMO at low-temperature on different substrates was shown as the path toward their application in 3D Li-ion batteries. ispartof: Journal of the Electrochemical Society vol:164 issue:14 pages:D954-D963 status: published

A nanocomposite electrolyte composed of a non-volatile ionic liquid, organic Li-salt and porous-inorganic material can be a promising option as a solid electrolyte material. We present a high-rate performance in solid-state lithium metal and Li-ion batteries using a silica-gel solid nanocomposite electrolyte (nano-SCE) made by the sol-gel method with a bis(fluorosulfonyl)imide (FSI)-based ionic liquid. The nano-SCE, composed of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl) imide (EMI-FSI) and Li-FSI confined in the mesoporous silica matrix, exhibits an ionic conductivity of 6.2 mS cm−1 at room temperature. The capacity of the Li-LiFePO4 cell using the EMI-FSI based nano-SCE reaches 150 mAh g−1 at 0.1C and 113 mAh g−1 at 1C, which is higher than that achieved by the other reported batteries that use a similar composite electrolyte. The C-rate performance of the prepared solid batteries is comparable to that of cells with the conventional lithium hexafluorophosphate (LiPF6) electrolyte. Our results show that impregnation of a liquid precursor is an efficient approach for an excellent electrode/electrolyte interface contact in the solid composite electrode as the reaction kinetics at the interface of the active mass and nano-SCE are sufficiently fast, and thus is advantageous compared with the other types of solid electrolytes.

In this study, we apply the economically feasible liquid ALD process to deposit a 2 nm amorphous MnO2 thin-film on our high surface-area 3D Ni nanomesh substrate, which shows a high surface to footprint area ratio (30 cm2:1 cm2 for 1 μm thick Ni nanomesh), and demonstrate its preliminary electrochemical activity as a cathode under N2 and O2. The excellent footprint charge density and faradaic efficiency can be attributed to the catalytic oxygen reduction reaction, followed by Li-intercalation thus forming a hybrid combination of Li-ion and Li-O2 activity, alleviating the detrimental deactivation process of pristine MnO2.

The desorption / adsorption of suppressor additive during Cu electroplating plays a critical role in the void-free filling of recessed features such as through-silicon vias (TSVs) used in 3-dimensional integration. A stochastic model was proposed for Polyethylene Glycol (PEG) as a suppressor additive in Cu electroplating. Using the proposed model, a program capable of simulating transient processes such as cyclic voltammograms (CVs) was developed. The steep change of current density due to suppressor desorption, as well as the characteristic hysteresis, observed in the CVs was shown in simulation. The dependency of PEG desorption / adsorption on various factors, including the bath composition, scan rate and molecular weight, was simulated. The simulation results were confronted side-by-side with the corresponding experimental measurements. An overall good qualitative match was shown.

We examine the electrodeposition of antimony (Sb), tellurium (Te) and their alloys from molten mixtures of acetamide - antimony chloride and tellurium chloride. The binary mixtures of acetamide with SbCl3 and TeCl 4 exhibit eutectic formation with large depressions of freezing points to below room temperature. At temperatures up to 100 °C, these mixtures are highly conductive and can be used to deposit elementary Sb and Te films at current density up to 7 A dm-2. Antimony telluride alloy films with composition between 20 and 81 at.% Te are obtained from ternary mixtures containing up to 0.48MSbCl3 and up to 0.12MTeCl4. Composition of the antimony telluride films can be controlled by adjusting bath composition and current density. cop. 2012 The Electrochemical Society.

In this paper we report on the electrochemical deposition of copper onto n‐type silicon with a 30 nm TiN barrier film. We show that the mechanism of nucleation and growth is dependent on the applied potential. At potentials more negative than −0.35 V, instantaneous nucleation of hemispherical clusters is followed by diffusion‐limited growth. In this potential regime, the nucleus density is essentially constant at about . At potentials more positive than −0.35 V, the nucleation and growth kinetics are more complex, and clusters consisting of several nuclei are formed. The cluster density decreases to about at −0.05 V. © 1999 The Electrochemical Society. All rights reserved.

The electrochemical deposition of Ni and Co on GaAs and GaP at pH 5 was investigated by means of cyclic voltammetry and rotating disk voltammetry. The current‐potential behavior of the two semiconductors in dilute metal ion solutions appeared to be different: at n‐GaP, a stepwise reduction of the metal ions was observed, whereas at n‐GaAs this was not the case. This observation can be explained on the basis of two alternative reaction mechanisms for the reduction of the monovalent intermediate. Under well‐chosen conditions of deposition potential and metal ion concentration, it appeared to be possible to form adherent n‐GaAs/Co, n‐GaAs/Ni, and n‐GaP/Co Schottky contacts with good rectifying properties. The barrier height of the n‐GaAs/Ni contacts appeared to increase as a function of time, leading to values of which were dependent on the deposition potential . At n‐GaAs/Co and n‐GaP/Co junctions, this aging effect was absent, leading to values of the barrier height which were independent of . It was further observed that the occurrence of side reactions during metal deposition may exert a great influence upon the properties of the metal/semiconductor junctions formed. © 1999 The Electrochemical Society. All rights reserved.

Electrodeposition is an excellent method for a site-selective and direct fabrication of catalyst nanoparticles for subsequent carbon nanotube (CNT) growth. Nickel nanoparticles with densities as high as 10 11 cm -2 and diameters down to 15 ± 4 nm are deposited on blanket and patterned TiN wafers. Ni nanoparticles are selectively placed at the bottom of submicrometer vias by through-mask electrodeposition. The spherical nanoparticles all produce aligned multiwalled CNTs. The CNT diameter is directly determined by the diameter of the as-deposited nanoparticles, which is tailored by the electrodeposition conditions. Such control of CNT size, density, and location represents an important step toward the implementation of CNTs in device fabrication.

Experimental observations are reported on the range of compositions and geometries for which void-free "superfilling" of rectangular trenches occurs during copper electrodeposition from acid sulfate solutions containing poly(ethylene glycol), chloride, bis(sodium sulfopropyl)disulfide, and l-(2-hydroxyethyl)-2-imidazolidine-thione. Observations were compared with predictions made with a model that included 17 species and reaction intermediates that participated in a network of 15 surface reactions as well as surface diffusion, and three homogeneous reactions. The numerical algorithm was designed to handle stiffness arising from reaction terms and computational efficiency required for interface movement. Accurately estimated values of the most sensitive model parameters were used to carry out simulations of shape evolution. One assumption was needed to bring the model into agreement with experimental trends for the "window" of superfilling conditions over the range investigated experimentally. Numerical results were found to track behavior typically observed during superfilling, such as an incubation period, bottom-up acceleration, and bump formation. Predictions of the distribution of adsorbed species during trench infill support the interpretation that superfilling arises from generation of a catalytic accelerator species within the trench in the presence of transport-limited competitive adsorption of suppressor and inhibitor additives.

The deposition of copper metallization is achieved from acidic copper sulfate solution containing small concentrations of chloride, suppressor, accelerator, and leveler. Void-free filling of trenches and vias results from the complex interplay between the additives in the solution. Here we report on the adsorption/desorption of the copper-suppressor-chloride complex in solutions without accelerator or leveler. We show that desorption of the suppressor complex occurs at a critical potential that is dependent on the pH, chloride concentration, cupric ion concentration, and suppressor concentration. We derive an expression for the critical potential from which we determine the composition of the complex. In addition, the solubility product of the complex is determined to be log K s = -14.4.

Bismuth and antimony are semimetals with a rhombohedral crystal structure and similar lattice parameters. alloys exhibit unusual electronic properties and are of interest for thermoelectric and magnetoelectronic devices. In this paper, we show that alloys can be electrodeposited from acidic chloride-based solutions and that a homogenous solid solution is obtained across the entire composition range. We show that bulk deposition is preceded by monolayer deposition at potentials negative to the equilibrium potential. The deposition/stripping reaction for bismuth is more reversible than for antimony leading to a small increase in the bismuth concentration in films compared to the concentration in solution at low Sb(III) concentrations. Thin films have a preferred (012) texture and the interplanar spacing is proportional to the film composition according to Vegard's rule. The grain size for thin films increases from about 1 μm for pure Bi to several micrometers for pure Sb. © 2003 The Electrochemical Society. All rights reserved.