Bath Composition Research Articles

Advancements in Sustainable PVDF Copolymer Membrane Preparation Using Rhodiasolv® PolarClean As an Alternative Eco-Friendly Solvent

In this work, Rhodiasolv® PolarClean was employed as a more sustainable solvent for the preparation of poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) flat sheet membranes via phase inversion technique by coupling vapour induced phase separation (VIPS) and non-solvent induced phase separation (NIPS) processes. Preliminary calculations based on Hansen solubility parameters well predicted the solubilization of the polymer in the selected solvent. The effect of exposure time on humidity and the influence of polyethylene glycol (PEG), polyvinyl pyrrolidone (PVP) and sulfonated polyether sulfone (S-PES) on membrane properties and performance, were evaluated. Three different coagulation bath compositions were also explored. The obtained membranes, prepared using a more sustainable approach, were compared with those produced with the traditional toxic solvent N-methyl-2-pyrrolidone (NMP) and characterised in terms of morphology, porosity, wettability, pore size, surface roughness and mechanical resistance. The potential influence of the new solvent on the crystallinity of PVDF-HFP-based membranes was also evaluated by infrared spectroscopy. The adjustment of the parameters investigated allowed tuning of the membrane pore size in the microfiltration (MF) and ultrafiltration (UF) range resulting in membranes with various morphologies. From the water permeability and rejection tests, performed with methylene blue dye, the prepared membranes showed their potentiality to be used in MF and UF applications.

Relation between Faradic Yields, Hydrogen Evolution and Pulsed Currents: Morphological and Fe Content Control in Zn and ZnFe Coatings

Long-term protection of metallic parts from atmospheric exposure is an important challenge and one of the most frequent way to ensure their corrosion resistance is the application of sacrificial zinc alloys coatings [1]. Among the various zinc electroplating baths, the alkaline zincate solutions has gained a wide range of applications thanks to its simple bath composition, good dispersion and efficient coverage ability. Nevertheless, its efficiency is very low in absence of additives, which affects the performances of the coatings by modifying the crystal growth and therefore the structural and mechanical properties. This is a result from the competition between dihydrogen production and the reduction of the metallic species present in the bath.The present study deals with the optimization of ZnFe sacrificial coating on steel and aluminum substrate in the frame of the ATLAS project -Alternative TechnoLogies for improved Anticorrosion Solutions- managed by the IRT M2P. After the analysis of the electrochemical behavior of the ZnFe electrolyte patented by the Coventya company and the UTINAM institute, pulsed currents will be implemented to extend the versatility of the coatings. Indeed, pulsed currents are known to act on various parameters such as improving the faradic yield or modifying morphologies and structures [2].The determination of a first panel of pulsed sequences (average current densities, cathodic peak current, cathodic pulse time and off-time) have been based on transient curves analysis from a zincate bath. Three sequences have been selected as they resulted in very different patterns in terms of electrochemical behavior and coatings characteristics. These sequences have been replicated and compared to DC current in several electrolytes, from the zincate bath to the commercial formula. For each set of parameters, the faradic yield has been measured and compared to the hydrogen generated during the electrolysis distributed between the absorbed one (measured by hot extraction) and the dihydrogen released into the reactor atmosphere (measured by mass spectrometry with a dedicated set- up). It is interesting to note that the obtained values strongly depend on pulsed sequences as well as electrolytes composition. Coatings were systematically produced and characterized. Morphology was observed using SEM and microstructure determined from XRD diffractograms: preferential orientation and crystal lattice and crystalline phases. The latest has required a specific methodological development.Finally, the identification of nucleation parameters by model simulation has been undertaken to describe the mechanisms involved in the first steps of zinc electrodeposition [3].[1] B. Chatterjee, « Electrodeposition of Zinc Alloys », p. 31.[2] X. Zhang, K. Tsay, J. Fahlman, and W. Qu, « Journal of Energy Storage, 26 p. 100966 (2019)[3] A. Milche, Electrochimica Acta, 48 p.2903-2913 (2003)

Influence of multi-component composition of dyeing bath in the membrane distillation performance

The influence of the multi-component composition of cotton and polyester dyeing baths was investigated in a DCMD process using a PTFE membrane, aiming to water reclamation from textile wastewater. The process was evaluated with each auxiliary, solutions combining auxiliary and dye, and residual water from pilot-scale dyeing baths. The salts used in the cotton dyeing bath did not influence the DCMD process, resulting in a similar rejection rate and permeate flux to those in dye solutions. The formic acid employed in the polyester dyeing bath resulted in high permeate fluxes but decreased the permeate quality by almost 33%. The surfactants (detergent and dispersant) demonstrated the most harmful behavior in the process, evidenced by a complete membrane wetting. An absence of synergy of the dyes and auxiliaries influencing the DCMD process was verified for the textile dyeing wastewater. This work enabled identifying the influence of each dyeing bath component in the rejection rate and permeate flux, allowing to find alternatives in mitigating the remaining gaps involving DCMD operation and the MD membranes. This work contributes to consolidating this promising technique in water reclamation from textile wastewater, encouraging research on membrane development and modification or integrated operations involving MD.

The influence of pH and current density for nano-silver electrodeposited in cyanide-free succinimide bath

The effects of pH and current density on cyanide-free succinimide baths were studied in this paper. The effect of pH on the electrochemical structure and electrochemical process were analyzed by electrochemical impedance spectroscopy (EIS). The reversibility of the bath with different pH was characterized by cyclic voltammetry (CV). The results showed that the electrodeposition process was irreversible in different pH baths. The highest polarizability and reversibility were observed at pH9 bath. The reason of highest polarizability at pH9 is due to the hydrolysis of succinimide and formation of NH3. The compositions of baths with different pH were measured by XPS, which confirmed the hydrolysis of succinimide and the singleness of silver ion's valence state. The nucleation process of silver at different deposition potentials that in the range of -0.4–0.7 V was studied by chronoamperometry. The comparison of dimensionless curves with Scharifker and Hills (SH) theoretical model showed that the nucleation of silver in bath was closer to instantaneous nucleation. The microscopic images of early nucleation were captured, which proved that nucleation was discontinuous and might interfere with each other. The nano-silver films were obtained by electrodeposition within the current density ranging from 0.4 to 0.7 A/dm2. The microstructure observed by scanning electron microscope (SEM). The results showed that grain size increased abnormally with the increase of current density and the silver film exhibited the finest grain size was obtained at the current density of 0.4 A/dm2. The phenomenon was caused by the instantaneous nucleation and the interaction between nucleation points.

Characterization and In Vitro Studies of Low Reflective Magnetite (Fe3O4) Thin Film on Stainless Steel 420A Developed by Chemical Method

Stainless steel has been the most demanded material for surgical utensil manufacture due to superior mechanical properties, sufficient wear, and corrosion resistance. Surgical grade 420A stainless steel is extensively used for producing sophisticated surgical instruments. Since these instruments are used under bright light conditions prevalent in operation theatres, the reflection from the material is significant which causes considerable strain to the eye of the surgeon. Surgical instruments with lower reflectance will be more efficient under these conditions. A low reflective thin -film coating has often been suggested to alleviate this inadmissible difficulty. This paper reports the development of an optimum parametric low reflective magnetite coating on the surface of SS 420A with a black color using chemical hot alkaline conversion coating technique and its bioactivity studies. Coating process parameters such as coating time, bath temperature, and chemical composition of bath are optimized using Taguchi optimization techniques. X-ray photoelectron spectroscopy (XPS) analysis was used to identify the composition of elements and the chemical condition of the developed coating. Surface morphological studies were accomplished with a scanning electron microscope (SEM). When coupled with an energy-dispersive X-ray analysis (EDAX), compositional information can also be collected simultaneously. Invitro cytotoxicity tests, corrosion behavior, the effect of sterilization temperature on adhesion property, and average percentage reflectance (R) of the developed coating have also been evaluated. These results suggest adopting the procedure for producing low reflective conversion coatings on minimally invasive surgical instruments produced from medical grade 420A stainless steel.

Оptimization of the chrome plating bath operation during the restoration of vehicle parts

Introduction. In the process of chrome plating of car parts, there is a change in the composition of the chrome plating bath, which affects the stability of the ongoing processes – the performance and quality of the chrome coating. Therefore, it is necessary to constantly monitor the chrome plating bath for the presence of foreign elements that can be formed during the operation of the bath during the reaction of the solution with the anode or cathode.Materials and methods. During the research, the necessary equipment was used, which made it possible to determine with sufficient accuracy the content of trivalent chromium and its effect on the electrolysis process – the performance and quality of chrome coatings. A well-known technique was used to determine the quality and performance.Results. When conducting studies of the obtained cold self-regulating chromium plating electrolyte, it was found that trivalent chromium has a significant effect on the stability of the chromium plating bath. The content of which can vary within 2...25 g/l during operation. As a result, it was found that the optimal amount of trivalent chromium is its content in the chromium plating bath from 2 to 15 g/l. With a lower or higher content, the electrolysis performance and the quality of the chrome coating decrease. It was also found that in order to maintain the optimal amount of trivalent chromium and increase the time for stable operation of the chromium bath, it is necessary to observe the ratio of the area of the anode and cathode (the coated surface of the part), the value of which is within 3...4.Discussion and conclusion. As a result of the conducted research, it will make it possible, under certain conditions, to carry out the process of chromium deposition from a cold self-regulating electrolyte, which will allow for stable chromium deposition at high productivity and the necessary quality of the coatings obtained. The main condition is to control and maintain the amount of trivalent chromium in the chromium plating electrolyte in the bath.

Facile one-step fabrication of all cellulose composites with unique optical performance from wood and bamboo pulp

Cellulosic substrates completely originating from biomass have gained increasing attention for utilization in photoelectric devices due to their biodegradability, sustainability, and renewability. Herein, a simple one-step strategy was used to fabricate transparent (84.2%–90% at 550 nm) all-cellulose composites (ACCs) with customized optical haze (14.7%–83.7% at 550 nm) from wood and bamboo pulp due to their variable solubility. Surface roughness, coagulation bath composition, and the size of the undissolved cellulose fibers contributed to optical haze regulation. Fabricated ACCs demonstrated water resistance, thermal stability, and good mechanical properties. Moreover, an enhancement in the power conversion efficiency of a perovskite solar cell was achieved by simple attachment. Compared with non-sustainable petroleum base materials, ACCs exhibit biodegradability and renewability, which makes the composites promising in large-scale production and various applications due to their tunable haze.

Microstructure Study and Morphology of Ni / Nano Al2O3 Composite Coating Synthesied by Electroless Plating

The electroless deposition method was used to prepare Ni-based nanocomposite coatings, this approach represents an alternate way of having coatings on the different substrates. Most of the previous literatures on this subject and work deals with a study the effect of the process conditions and, Bath composition on the microstructure at the macroscale of Ni-Al2O3 composite coatings. Though, effect on the step structure of the composition of the bath and microstructure are little, the present work aims to study the effect of hard ceramic Al2O3 nanoparticles at different concentrations (0.0, 0.5, 1.0, 2, 4) g/L, on the phase structure, microstructure and morphology of Al2O3 nanocomposite coating, in order to enhance the mechanical, plysical and chemical properties of nanocomposite coating. In this paper, An X-Ray diffraction method, spectroscopy (EDS), energy dispersive, and scanning electron microscope (SEM) were studied in the phase structure, chemical composition and morphological nanocomposition coatings. In the present paper, is evident from EDS study that the composite coating consists of Ni and nanoparticles of Al2O3. The micrograph study of the EDS showed that A flat and smooth surface is present in the deposited nanocomposite coating. Uniform distribution of nanoparticles of alumina within Ni-Matrix. And the XRD study showed the crystalline structure of the Ni- Al2O3 nanocomposite coating.

Electroless plating of Sn/Cu/Zn triple layer on AA6082 aluminum alloy

To enhance the corrosion resistance of an aluminum (Al) 6082 alloy, our research used electroless deposition to coat a trio sequence of Zn–Cu–Sn layers: zinc, copper and tin. To isolate the reactions and micro-mechanisms in the tin coating, the Zn–Cu layering parameters of time, temperature, and bath concentration were held constant while varying those during the Sn electroless deposition. Microstructures and layer thicknesses of the coated samples were studied using both optical and scanning electron microscopy (SEM). Local chemical compositions were analyzed using energy dispersive spectroscopy (EDS). Tin deposition on the Cu layer starts with a displacement reaction formed by the nucleation of discontinuous bulges that gradually grow into inhomogeneous crowns. During Sn deposition, surface Cu consumption and bath composition varies hindering access to displacement reactants, thus curtailing the significance of displacement. However, deposition continues via reduction and disproportionation directly tied to the solution. Peak layer quality was deposited at a temperature of 45 °C with a 1.5 times concentration for 1200 s. Anti-corrosion behavior of the Sn-coated sample was examined by Electrochemical Impedance Spectroscopy (EIS) to detect notable enhancement.

Establishing relationships between bath composition and the properties of amorphous Ni–Mo alloys obtained by electrodeposition

In this study, the Response Surface Methodology (RSM) was used as an optimization tool along with a complete 3² factorial experimental design with 4 central points to determine the significant factors on the electrodeposition process of Ni-Mo alloys and support establishing relationships between the independent variables and the properties of the coatings. Specifically, the influence of the concentrations of nickel sulfate and sodium molybdate on different electroplating responses was evaluated. The models proposed in this work were validated with experiments performed within the level considered for both entry variables; no experimental combination of any level was considered for this purpose. Coatings with a high Mo percentage and distinct morphologies were produced. XRD diffractograms indicated that they were all amorphous. Variations in nickel sulfate (Ni) and sodium molybdate (Mo) concentrations in the bath produced coatings with different properties. The optimal bath condition found for Mo at% was constituted by a Ni:Mo concentration ratio of 7.5:5, producing a film with 29 at% of Mo. The optimal Ni:Mo for CE% and Rp was 10:3; highest CE% and Rp were 47% and 19,314 Ω/cm², respectively. The films produced in this work can be applied as anticorrosive coatings

Mapping wet vs gel spinning in Hansen space

The composition of coagulation baths for solution spun fibers are typically established through trial and error. No method currently exists to quantifiably differentiate wet from gel fiber spinning. Hansen Solubility Parameters (HSPs) characterize materials using a 3-dimensional coordinate system for dispersive (δD), dipole-dipole (δP), and hydrogen bonding (δH) forces. This coordinate system was used to quantify the affinity of coagulation baths with respect to the polymer in the spinning solution. A correlation based on radial energy distribution (RED) was seen to consistently differentiate wet from gel spinning. If the HSP distance between the coagulation bath and polymer (Ra) is less than or equal to the inherent interaction radius (Ro) of the polymer (RED ≤ 1), coagulant diffusion inward is observed, which is critical for wet spinning. If Ra is greater than Ro (RED > 1), negligible amounts of coagulant diffusion inward is observed, which is critical for gel spinning. This quantitative approach has applicability to a range of polymeric materials such as fiber, film, and membrane technologies.

Zinc Electrodeposition in Acetate‐based Water‐in‐Salt Electrolyte: Experimental and Theoretical Studies

AbstractZinc electroplating has found applications in many fields. The chemical composition of the electrodeposition bath can have a great impact on the final coating quality and the economics of the process. In traditional aqueous electrolytes, zinc deposition competes with the hydrogen evolution and oxygen reduction reactions, which can lead to hydrogen embrittlement of the substrate as well as decrease in efficiency. Highly concentrated water‐in‐salt electrolytes can suppress these reactions significantly. Here, we show that electrodeposition of zinc with high efficiencies can be achieved using an acetate‐based water‐in‐salt electrolyte at room temperature. Nucleation studies confirm that at potentials more negative than −1.30 V vs. Ag/AgCl, the three‐dimensional (3D) nucleation process becomes instantaneous, while at more positive potentials it is progressive. Using two of the most common nucleation and growth models, Scharifker‐Mostany and Mirkin‐Nilov‐Heerman‐Tarallo, nucleation parameters such as the nucleation rate constant and nuclei density are found, showing a good agreement between the two models.

Friction and wear behaviour of BN(h) and Ag incorporated nickel phosphorous coatings under dry reciprocating sliding conditions

ABSTRACT Ni–P–BN(h)–Ag hybrid composite coatings were fabricated on the steel substrate by a scalable electroless deposition process. The optimum bath composition and operating conditions were selected to obtain defect-free composite coatings with ∼50 μm thickness. Further, to enhance the hardness, as-deposited coatings were subjected to heat treatment in a tubular furnace at 400°C for 1 h. The dry sliding wear behaviour of the as-deposited (AD) and heat-treated (HT400) composite coatings was evaluated using a linear reciprocating tribometer. The average friction coefficient of the hybrid coating was ∼0.14 (in as-deposited condition) and ∼0.16 (in heat-treated condition); these values represent 51.72% and 52.94% reduction over non-hybrid Ni-P coatings. The specific wear rate of the as-deposited and heattreated composite coatings was found to be 50% and 43% lower, respectively, than that of conventional Ni–P coatings. Detailed wear track analysis was carried out to identify underlying wear mechanisms and tribochemical interactions.

Synthesis of NiWP coated diamonds particles with enhanced mechanical and anti-corrosion property for diamond wires of the sawing process

In this study, NiWP ternary shell layer on diamond powder was synthesized by electroless deposition method. The characteristics of thin films with different deposition parameters such as bath compositions, temperature, and pH were studied. The composition of tungsten in NiWP thin films could be varied by the concentration of sodium tungstate, and it was saturated as ~24 wt%. With the decrease of phosphorous content, crystal structure was changed from amorphous to polycrystalline by the addition of sodium tungstate in the electrolyte. The incorporation of tungsten into NiP films could improve the hardness and the corrosion resistivity, which is critical for utilizing the diamond powders as a sawing applications. From systematic investigations, the optimal electroless deposition of NiWP on the diamond powders was obtained at 70 °C with pH 9.

Effect of the Nanostructured Zn/Cu Electrocatalyst Morphology on the Electrochemical Reduction of CO2 to Value-Added Chemicals.

Zn/Cu electrocatalysts were synthesized by the electrodeposition method with various bath compositions and deposition times. X-ray diffraction results confirmed the presence of (101) and (002) lattice structures for all the deposited Zn nanoparticles. However, a bulky (hexagonal) structure with particle size in the range of 1–10 μm was obtained from a high-Zn-concentration bath, whereas a fern-like dendritic structure was produced using a low Zn concentration. A larger particle size of Zn dendrites could also be obtained when Cu2+ ions were added to the high-Zn-concentration bath. The catalysts were tested in the electrochemical reduction of CO2 (CO2RR) using an H-cell type reactor under ambient conditions. Despite the different sizes/shapes, the CO2RR products obtained on the nanostructured Zn catalysts depended largely on their morphologies. All the dendritic structures led to high CO production rates, while the bulky Zn structure produced formate as the major product, with limited amounts of gaseous CO and H2. The highest CO/H2 production rate ratio of 4.7 and a stable CO production rate of 3.55 μmol/min were obtained over the dendritic structure of the Zn/Cu–Na200 catalyst at −1.6 V vs. Ag/AgCl during 4 h CO2RR. The dissolution and re-deposition of Zn nanoparticles occurred but did not affect the activity and selectivity in the CO2RR of the electrodeposited Zn catalysts. The present results show the possibilities to enhance the activity and to control the selectivity of CO2RR products on nanostructured Zn catalysts.

Preparation of Co-Fe-Ni alloy micropillar by microanode-guided electroplating

Microanode-guided electroplating (MAGE) was performed to prepare cobalt-iron-nickel alloying micropillars. The electrolyte was prepared by fixing [Fe2+] at 0.040 M and varying [Co2+] in 0.040–0.100 M and [Ni2+] in 0.30–0.60 M. The effect of bath composition on the compositional, mechanical, and magnetic properties of the alloying micropillars was investigated. Resulting from FE-SEM and EDS, all the micropillars demonstrated a smooth morphology but in different compositions depending on the bath composition. Through XRD analysis, the micropillars were characterized in nanocrystals of Co-Ni and Co7Fe3. After nano-indentation testing, the reduced Young’s modulus of the pillars was estimated at 103.1–185 GPa and the hardness at 5.70–6.38 GPa. Investigation of all the specimens with VSM, Co61Fe27Ni12 and Co63Fe25Ni12 displayed the notable saturation magnetization (Ms = 180 and 175 emu/g) and the lowest coercive magnetic field (Hc = 2.1 and 1.4 Oe) among them. The mechanism of anomalous Co-Fe-Ni electrodeposition is proposed.

Mechanical, Tribological, and Corrosion Properties of Composite NiP-Al2O3 With Different Amount of Particles

Abstract In this study, the influence of Al2O3 particle amounts on the mechanical, tribological, and corrosion properties of the composite NiP-Al2O3 coating was evaluated. AISI 4140 steel was coated with NiP through an autocatalytic bath with the addition of Al2O3 particles maintained in suspension by mechanical stirring. Following, the coated samples were annealed at 600 °C to increase the hardness and to create an interdiffusion layer, which improves coating adhesion and corrosion resistance. The coating surface was characterized by scanning electron microscope (SEM)/energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), microhardness, wear resistance, and corrosion tests. The results showed that the coating particles’ amount depends on the bath agitation speed, the sample orientation during the deposition, and the volume of Al2O3 particles in the bath composition. Also, the number of particles in the coating affects the deposition kinetics and the thickness of the interdiffusion layer, which affects the wear and corrosion resistance.

Comparative Study of Sheet Resistance Stability of Electro-Deposited Ni/Co - Alloy Thin Films

Cu is conventionally used for interconnect material in most of high performance and high integration of logic devices because Cu has low conductivity as 1.7×10－8 Ω･m and also has excellent electromigration resistance. However, Cu requires a barrier layer for eliminating Cu diffusion into SiO2 or Si. Because of the limitation of the barrier layer thickness, the effective resistance of the wiring including the barrier layer greatly increases with decreasing of the width of Cu wiring less than 10 nm. Therefore, many researches have been reported about the development of barrier layer-free wiring technology using Co or Ru with low resistivity compared to Cu wiring system. Ni has similar physical properties e.g. resistivity, thermal expansion coefficient, diffusion coefficient, etc. like Co or Ru, however, few research on electrical properties has been done so far. In this study, Ni, Ni-Co alloys, and Co are deposited by electrodeposition and crystallographic structure and electrical properties were evaluated.A Ni or W (5 nm) seed layer were deposited onto thermally grown SiO2/Si(001) substrates (10 mm sq.) at R.T. by RF sputtering. After forming the seed layer, Ni or Ni-Co alloy or Co thin film (50 nm) was deposited. Table 1 shows the composition of electrodeposition bath. After the deposition, all samples were annealed in argon atmosphere (0.1 Torr) at 450°C for 30 minutes. Elemental analysis was done by Energy Dispersive X-ray spectrometry (EDX). The crystal structure, Chemical bonding state and electrical properties were evaluated by X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and 2-terminal Method, respectively, before and after annealing.Figure 1 shows the sheet resistance change of Ni, Ni-Co alloy, or Co films before and after 450°C - 30 minutes annealing using (a) Ni and (b) W as a seed layer. There was no significant difference in sheet resistance between the Ni or W seed layer samples. In the case of Ni or Ni-Co alloy films, the sheet resistance after annealing was very stable for both seed layers, Ni and W. On the other hand, the sheet resistance of Co films increased and they were considered to be oxidized by XPS and XRD results. Co film by electrodeposition was oxidized but Ni and Ni-Co alloy films were not oxidized by annealing, so they are better wiring metal than Co in terms of oxidation resistance. Figure 1

Electrodeposition of Platinum Group Metals for Interconnects Beyond 5nm Technology Node

For technology nodes beyond 5 nm, copper metal may not be feasible as conductor material in Damascene interconnects.1 The bulk resistivity of copper increases exponentially and electromigration of copper is possible with the scaling down of the technology nodes. Metals such as inert platinum group metals have been proposed as alternative metal conductors for interconnects.2 Platinum group metals exhibit less electron scattering and lower electromigration in narrow line widths compared to copper; the electron scattering is proportional to the bulk resistivity. Thus, certain platinum group metals, e.g., ruthenium2, have been proposed as alternative conductors for interconnects.3 Ruthenium electrodeposition needs further development because of slow kinetics, resulting in poor control of morphology, and defects in the film due to hydrogen evolution at the high overpotential required to initiate ruthenium deposition.4 Another challenge is that ruthenium has multiple oxidation states, which may result in disproportionate reactions, and, thus, electrodeposition may not occur reproducibly.3This study investigates the electrodeposition of ruthenium from nitrosyl ruthenium complexes, and/or inorganic ruthenium compounds such as chlorides, sulfates or phosphates in acidic electrolytes. Figure 1 shows ruthenium electrodeposited on an ultrathin seed layer with high sheet resistance. Electrodeposition techniques such as chronoamperometry and chronopotentiometry are compared for the initiation of ruthenium nuclei on such highly-resistive (up to 400 Ω/sq) seed layers. In this study, a multi-step electrodeposition process was developed for the nucleation, then growth of a uniform, void-free ruthenium film. A constant voltage was applied for a short time (few seconds) to initiate plating by providing the overpotential necessary to form ruthenium nuclei. Next, a low current density was applied to grow the film to the desired thickness (50 – 100 nm). This method allows for minimal hydrogen evolution and prevents void formation since the high potential is applied for a short time compared to other typical pulse plating methods. The multi-step method is reproducible and results in uniform plating on 200 mm wafer scale by utilizing plating tool shields that can control center and edge plating rates. This talk describes the effect of electrolyte bath composition and plating parameters on the morphology, adhesion and uniformity of the electrodeposited ruthenium.Figure 1: Electrodeposited ruthenium on Si substrate with ultrathin seed layer.1) Chen, Q.; Lin, X.; Valvede, C.; Paneccasio, V.; Hurtubise, R.; Ye, P.; Kudrak, E.; Abys, J., Electroless copper deposition on ruthenium for damascene interconnects. ECS Transactions. 2007, 6 (8), 179-184.2) Mainka, G.; Beitel G.; Schnabel R.F.; Saenger, A.; Dehm, C., Chemical mechanical polishing of iridium and iridium oxide for damascene process. Journal of the Electrochemical Society. 2001, 148, G552-G558.3) Bernasconi, R.; Magagnin, L., Review—Ruthenium as diffusion barrier layer in electronic interconnects: Current literature with a focus on electrochemical deposition methods. Journal of the Electrochemical Society. 2019, 166 (1), D3219-D3225.4) Oppedisano, D.K.; Jones, L.A.; Junk, T.; Bhargava, S.K., Ruthenium electrodeposition from aqueous solution at high cathodic overpotential. Journal of the Electrochemical Society. 2014, 161 (10), D489-D494.AcknowledgementThe authors acknowledge the researchers of the Microelectronics Research Laboratory (MRL) at the IBM T. J. Watson Research Center, for the fabrication work. Figure 1

MULTI-OBJECTIVE OPTIMIZATION OF SOLUTION’S COMPOSITION ON THE BASE OF NICKEL COMPLEXES WITH GLYCINE AND SUCCINIC ACID FOR ELECTROLESS DEPOSITION OF Ni-P ALLOY

In this paper the effect of parameters such as concentration of glycine, succinic acid and bath pH on the technological parameters of the electroless deposition of nickel-phosphorus alloy coatings (deposition rate, specific pH change during deposition), the composition of the coatings and their properties (microhardness after heat treatment) was studied. Experimental design of 23 central composite design (CCD) was used to evaluate the appearance of coating, rate, specific pH change, the chemical composition of alloys, and microhardness, as well as to optimize the electroless process of the alloy using Response Surface Methodology (RSM) associated with experimental design. The microhardness of the deposited coatings was 4.6 - 6.8 GPa and after heat treatment at 400 °C for 0.5 h increased to 9.7-11.6 GPa, which corresponds to hard chromium coatings obtained by electrodeposition from solutions of chromic acid. The Harrington desirability function was applied for optimization. The optimal composition of bath (in mol/l) and electroless conditions are proposed: NiSO4·6H2O – 0.12, NaH2PO2·H2O– 0.36, NH2CH2COOH – 0.30, (CH2)2(COOH)2 – 0.20, Pb(CH3COO)2 - 10-5; pH – 5.8. Temperature – 70 – 96 ºС. An acceptable rate deposition of 8 (70 ºС) and 34 (95 ºС) mg/(cm2∙h) was observed for an alloy obtained under optimal conditions from an solution of optimal composition. Under these conditions, the coating contained 6 wt.% of phosphorus. Therefore, the results of this work show the importance of using optimization techniques to obtain metallic coatings with controlled properties for different types of applications.