Morphology Of Copper Deposits Research Articles

Stabilizing effects of mercapto additives on Eco friendly autocatalytic copper nano film deposition

The stabilizing effects of mercapto additives such as 2-Mercaptoimidazole (2-MI) and 2-Mercaptobenzimidazole (2-MBI) in autocatalytic copper nano film deposition have been investigated in this work. Eco friendly Glyoxylic acid is chosen as the reducing agent in the Glycerol containing methanesulphonate bath. The pH is regulated to a range of 13.00 ± 0.25, with the help of Potassium hydroxide. The bath is optimized at 45 °C, followed by the addition of 2-Mercaptoimidazole (2-MI) and Mercaptobenzimidazole (2-MBI) to the bath. In the glycerol bath, it was found that the deposition was inhibited, owing to the addition of the stabilizer 2-Mercaptoimidazole (2-MI). Moreover, 2-Mercaptobenzimidazole (2-MBI), when employed resulted in an accelerated deposition rate of nano copper deposits. Deposition rate and thickness of the deposit have also been calculated by gravimetric method. Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and X-Ray Diffraction techniques have been used to assess the surface properties and structural morphology of copper deposits. Electrochemical measurements were evaluated from Cyclic Voltammetry (CV) and Tafel Polarization methods.

Copper electrodeposition under a weak magnetic field: effect on the texturing and properties of the deposits

The effect of a weak magnetic field (induction of 0.5 to 0.7 mT) on the electrodeposition process and the formation of crystallographic texture, morphology and properties of copper deposits has been considered. Electrodeposition studies were performed using cyclic voltammetry, chronoamperometry, and chronopotentiometry. X-ray texture analysis and scanning electron microscopy observations were used to study the texture and the morphology of the copper deposits. Some of their properties were obtained by measuring their microhardness and reflectivity. The effects of decreasing the rate of copper electrodeposition, enhancing texture formation and refinement of grain aggregates of the surface of copper films under the influence of a weak magnetic field have been evidenced. The interrelation of the texture and morphology of the copper electrodeposit surface with their microhardness and reflectivity have been revealed. The conditions for obtaining copper deposits with enhanced microhardness and reflectivity have been determined. It is shown that the electrochemical deposition with a weak magnetic field is a promising direction for obtaining materials with desired properties, without using strong magnetic fields and adding surfactants to the electrolyte.

Pengaruh Konsentrasi Tembaga dan Rapat Arus terhadap Morfologi Endapan Elektrodeposisi Tembaga

Copper deposits have been obtained by the electrolysis method using copper sulfate and sulfuric acid. The effect of copper concentration and current density on the surface morphology of copper deposits and current efficiency have been studied. The variation of copper concentration is 0.04 M and 0.8 M and the variation of current density is 2-8 A/dm2. The copper deposits will be photographed macro, weighed and characterized by Scanning Electron Microscope (SEM) to determine the surface morphology of deposits and Energy-Dispersive X-ray spectroscopy (EDX) to determine the chemical composition of deposits. The surface morphology of copper deposits in the form of compact and without nodules was reached at copper concentration is 0.8 M and the current density is 2 A/dm2 with the average of current efficiency is 96%.

Effect of concurrent ball milling on cementation reactions: The case of Cu-Al system

Despite a strong thermodynamic tendency, cementation by aluminum of relatively noble metals from sulfate solutions involves a rather slow kinetics due to the presence of the passive oxide film on the aluminum surface. We know from the literature that small amounts of chloride ion can reduce the dimension of the problem. In this paper, we investigate the additional effect of concurrent ball milling on the enhancement of the cementation kinetics of Cu-Al system as a case study. The cementation tests were carried out in a polyamide jar placed in a planetary ball mill. In the first part of the study, the effect of rotation speed of the milling jar, number of alumina milling balls, particle size of the aluminum powder, and the initial hydrogen ion concentration on the copper recovery was studied and optimized using a central composite design of experiments. In the second part, we investigated the kinetics and mechanism of the cementation process under the optimum conditions obtained from the first part. The results show that the concurrent ball milling can shorten or even remove the initial slow rate period, known as the induction period. It also alters the rate-controlling mechanism from chemical to boundary layer diffusion revealed by a decrease in the activation energy from 79 to 18 kJ mol−1. The morphology of copper deposits obtained under ball milling condition was found to be botryoidal in contrast to the typical dendritic structure. The findings overall support the beneficial role of the simultaneous ball milling in lowering the kinetic barrier of cementation reactions on the aluminum surface.

Low Temperature Soldering Surface-Mount Electronic Components with Hydrogen Assisted Copper Electroplating

ABSTRACTCopper growth for the development of electroplating technique as a low-temperature soldering procedure represents a useful method for the formation of metal deposits, allowing modification of the thickness and morphology of the soldering joints. The approach is particularly useful for soldering electronic components to a plastic 3D printed substrate. To accelerate the soldering process hydrogen assisted electroplating (HAE) method was employed at room temperature. The experiments were designed by making a small electrochemical cell around the gap on a printed circuit board (PCB) or a 3D printed conductive track. During the experiment, water electrolysis was observed, which released hydrogen bubbles. The hydrogen bubbles caused the structure of the electroplated layer to be more porous, but with a similar conductivity as solid copper and a remarkable mechanical strength suitable for use as interconnects on an electronic circuit. Our electrochemical data and video recorded images show a fast and reliable copper electrodeposition in less than 1 minute. The morphology of copper deposits on a 3D printed structure was studied with the scanning electron microscopy (SEM). A reliable soldering process was demonstrated for a surface mount light emitting diode (LED) on a PCB. Further experiments are required to optimize the soldering process for faster and more reliable electroplating, particularly for 3D printed substrates.

Growth mechanisms of spatially separated copper dendrites in pores of a SiO2 template

n-Si/SiO2(Cu) structures with different morphologies of copper deposits are produced using the template synthesis method. Deposition of Cu nanostructures and their structural features is thoroughly studied, and mechanisms for the formation of compact and dendrite-like deposits in the pores of the SiO2 template on the n-type single-crystal silicon substrate are established. Spatially separated copper dendrites are obtained and used to investigate the efficiency of Raman scattering enhancement using the aqueous solution of the Rhodamine 6G dye.

Fabrication of Copper/Single-Walled Carbon Nanotube Composites by Electrodeposition Using Free-Standing Nanotube Film

Copper/single-walled carbon nanotube (SWCNT) composites were fabricated by electrodeposition using a freestanding SWCNT film as a template. The SWCNT films were directly electrodeposited to form copper/SWCNT composites. An acidic copper sulfate bath was employed as a basic plating bath, and the effects of additives to the basic bath on the morphologies of copper deposits were examined. Poly(ethylene glycol), chloride ions (Cl−), bis(3-sulfopropyl)disulfide (SPS), and Janus green B (JGB) were added individually or in combination as additives. Electrodeposition of copper occurred only on the surface of the SWCNT film when using the basic plating bath without additives. In contrast, copper was deposited not only on the surface but also in the interior of the SWCNT film when using the plating baths containing at least PEG and Cl−, resulting in copper/SWCNT composites. Electrodeposition of copper inside the SWCNT film was accelerated dramatically when all four additives (PEG, Cl−, SPS, and JGB) were added to the basic bath. This novel fabrication method of copper/CNT composites using CNT films as templates can be applied to the fabrication of various types of metal/CNT composites.

Surface morphology of copper deposits by using azine derivatives on an ecofriendly electroless bath

This article reports the effect of azine stabilizers such as pyridine, 2,2'-bipyridine and 1,10-phenanthroline during electroless deposition of copper. In this work, the biodegradable copper methanesulphonate was used instead of the traditionally used copper sulphate and the environmentally safe polyhydroxylic compound xylitol was used as the complexing agent. Commercial para-formaldehyde was used as the reducing agent and potassium hydroxide (KOH) was used to optimize the bath in alkaline medium at pH 13.25. Surface morphologies of the electroless coated copper (Cu) substrates were investigated by atomic force microscopic (AFM) analysis. Crystallite size and specific surface area of copper thin film were observed by x-ray diffraction (XRD). Electrochemical characteristics were studied by cyclic voltammetry (CV) and Tafel polarization. The value of charge transfer resistance and double layer capacitance were determined by impedance techniques. In this xylitol bath, 2,2'-bipyridine was found to act as an enhancer but the results are not very different from the plain xylitol bath. Pyridine acted as a strong inhibitor and 1,10-phenanthroline was a good accelerator. All stabilizers provide high stability to the bath at 28 ± 2°C with 1 ppm addition.

Morphology of Copper Deposits Obtained by Metallic Electrodeposition

Electrochemical deposition of copper from copper nitrate aqueous electrolyte on graphite substrate was investigated at current densities between 0.03mA/cm2 - 1.36mA/cm2 and in the voltage range of 3V to 15V. The surface morphology and elemental composition of the resultant deposit were characterized by electron microprobe analysis (EMPA). These images illustrate the influence of current density on the shape of copper electrodeposited on the electrode surface. Rods, polyhedral bodies, pentagonal pyramids, dendritics, spiked spheres or cauliflower-like shapes are observed depending on the electrodeposition conditions.

Copper Deposition and Formation of Nano-Particles

The cementation of copper ions from copper sulfate solution was studied using iron wire and iron powder. The influence of initial copper concentration has considerable effect on cumulative copper deposition. The copper deposition rate data could be interpreted by using shrinking core model. The effects of temperature and pH were substantial and have been studied and interpreted. The activation energy of the system within the temperature range of 23–54°C was found to be 14.23 (iron wire) and 30.20 kJ per mol (iron powder), respectively. The morphology of copper deposits studied showed that the reactions have the potential to produce particle sizes within nano range.

English

This article focuses on the effects and applications of ethylenediamine dithiocarbamate (EDADTC) on coordination and electro chemistry. EDADTC shows stable palladium (II) metal complex in organosulphur chemistry. Since they have soft sulphur donor atoms can make a strong metal binding property, act as the ligand and stable above pH 12. Due to their water soluble tendency, flow of electron from alkyl group to nitrogen, inductive effect and conjugation effect proved the stabilizing property in electroless plating process. EDADTC has improved the physical property and produce the quality deposits in electroless copper plating process. The palladium (II) metal complex was characterized by Rapid Elemental Analysis. The structure of the stable complex was confirmed with Electronic and I.R Spectral Analysis. The surface morphologies of copper deposits were characterized by AFM studies. The crystallite sizes of the copper deposits were measured by XRD studies and the quality of the copper deposits was investigated by cyclic voltammetry studies

Influence of imidazole and benzotriazole on electroless copper plating

In this study, the effect of imidazole and benzotriazole as primary stabilisers in saccharose and xylitol based copper electroless baths were studied. Copper methane sulphate was used as the complexing agent instead of copper sulphate and para formaldehyde was used as the reducing agent in the bath. The surface morphologies of copper deposits were characterised by SEM, AFM and XRD studies. The electrochemical characteristics were studied by cyclic voltametry to understand the role of the stabilisers in electroless deposition. In the saccharose bath, the imidazole and benzotriazole acted as inhibitors and best deposition was obtained at pH of 12·75. Benzotriazole afforded smoother and shiner deposits than imidazole. In xylitol bath, the stabilizers acted as accelerators and optimum deposition occurred at a pH of 13·25.

AFM Studies of the Effect of Chloride Ion on the Morphology of the Copper Electroplating Surface

The influence of plating mode, chloride ion on morphology of copper deposits has been studied on pure copper substrate. The electroplating was conducted at 50mA/〖cm〗^2 , 25°C in cupric sulfate-sulfuric acid bath with various chloride additions 0.001-0.01 ml. The morphology and grain sizes of the electrodeposited copper were examined by atomic force microscopy. The maximum surface roughness and grain sizes of copper deposit were obtained when it was deposited with 0.01 ml of chloride ions. Small particles were observed on the surface of the copper film electroplated with the addition of chloride ions up to the amount of 0.001 ml.

Influence of the Hydrophobic Groups on Quaternary Ammonium Additives for Copper Electrodeposition

A series of quaternary ammonium compounds with different hydrophobic groups as spacers were synthesized. The influence of the hydrophobic groups on the additives for copper electrodeposition was investigated using a galvanostatic measurement on a RDE electrode. The increase of the length of the alkyl chain within the compounds enhances the suppressing capability. The introduction of a hydroxyl group or a phenyl ring into the hydrophobic groups in the molecular structures reduces the suppressing capacity. The results obtained from SEM measurements indicate that the presence of the quaternary ammonium compounds in the electrolytes may produce regular and relative leveling morphologies of copper deposits. The via-filling experiments without SPS exhibit that an almost complete filling was achieved for compound 1d (C6 alkyl chain as a hydrophobic group), whereas a bad filling was obtained for compound 1a (C3-OH chain as a hydrophobic group). With SPS, the vias were perfectly filled both for compound 1a and 1d. However, the initial increment of growth was still conformal for the compound 1a. These results indicate the influence of the hydrophobic groups of the quaternary ammonium compounds on the filling behaviors and they are in agreement with the galvanostatic measurements at different electrode rotation speeds.

Comparison of open porous copper structures obtained by the different current regimes of electrolysis

Formation of open porous copper structures by the electrodeposition processes in the hydrogen co-deposition range was considered. Morphologies of copper deposits obtained by the reversing current (RC) regimes at the same average current density but with the different the anodic current density/anodic pulse ratios were compared with those obtained by the pulsating current (PC) regime at the same average current density and in the constant galvanostatic mode at the current density which was equal to this average current density. The considerable increase of the specific surface area of the honeycomb-like structures, determined by the increase of number of holes, as well as by the decrease of both holes size and wall width among them, can be attained if the appropriate parameters of the RC regimes are applied. In this way, it is shown that the regime of reversing current (RC) is superior in the production of open porous structures suitable to be used as electrodes in many electrochemical devices in relation to other current regimes of electrolysis, such as the PC and the galvanostatic regimes.

Effect of the anodic current density on copper electrodeposition in the hydrogen co-deposition range by the reversing current (RC) regime

In this study, the effect of the anodic current density in the regime of reversing current (RC) on the quantity of evolved hydrogen and morphology of copper deposits was considered. The quantity of evolved hydrogen was quantified by the determination of the average current efficiency for hydrogen evolution reaction, while morphology and internal structures of electrodeposited copper were analyzed using scanning electron (SEM) and optical microscopy techniques, respectively. In all RC experiments, the cathodic current density of 440 mA/cm 2, cathodic pulse of 10 ms and anodic pulse of 5 ms were applied, while the analyzed anodic current densities were: 40, 240, 440 and 640 mA/cm 2. The number, size and shape of holes formed of detached hydrogen bubbles strongly depended on the selected parameters of square waves RC. Due to the decrease of the quantity of evolved hydrogen with the increasing anodic current density, the change of morphology of copper deposits formed around holes from cauliflower-like agglomerates of copper grains to dendrites was observed. Honeycomb-like structures were formed with the anodic current density values up to 440 mA/cm 2. The compactness of the honeycomb-like structures increased with the increase of the anodic current density. The improvement of structural characteristics of the honeycomb-like electrodes was achieved by the application of the RC regime in comparison with both the pulsating current (PC) and constant galvanostatic regimes. It was found that the regime of reversing current is superior in the production of the honeycomb-like electrodes in relation to other current regimes of electrolysis.

Effect of carbon fiber surface treatment on Cu electrodeposition: The electrochemical behavior and the morphology of Cu deposits

The relationship between surface functional groups and electrochemical behaviors of polyacrylonitrile (PAN)-based carbon fibers (CFs) differentiated by oxidation treatment in air was studied. The chemical character of the CFs surface was estimated by X-ray photoelectron spectroscopy (XPS) and the electrochemical behavior of treated CFs in CuSO4 plating solution was studied by electrochemical setup. The influence of functional groups on the morphology of copper deposits was characterized by field-emission scanning electron microscopy (FESEM). It was found that the O/C atomic ratio rose rapidly from 23.05% (as-received carbon fibers) to 42.83% as the oxidation temperature was increased to 400°C and the content of –CO was the highest. Concentrations and types of the functional groups on CFs surface showed a close connection with the electrochemical response of CFs in CuSO4 plating bath. It was showed that Cu electrodeposition was the interaction of applied voltage and the reduction of surface functional groups. With the functional groups increased, the quantities of the Cu nuclei increased, further the morphology of deposited Cu was affected.

Influence of ionic equilibrium in the CuSO4–H2SO4–H2O system on the formation of irregular electrodeposits of copper

The relative concentration of hydrogen ion (H+) as a function of sulfuric acid (H2SO4) concentration (calculated using Pitzer's model) and the electrochemical processes by which irregular copper deposits are formed were correlated. Irregular deposits are formed by potentiostatic electrodeposition at a high overpotential where the hydrogen evolution reaction occurs parallel to copper electrodeposition. Two sets of acid sulfate solutions were analyzed. In one set of experiments, the concentration of CuSO4 was constant while the concentration of H2SO4 was varied. The other set of experiments was performed with a constant concentration of H2SO4 and different concentrations of CuSO4. Then, the volumes of the evolved hydrogen (calculated as the average current efficiencies of hydrogen evolution) and the morphologies of copper deposits, characterized by the SEM technique, obtained for the same ratio of CuSO4/H2SO4 were mutually compared and discussed in terms of the relative concentrations of hydrogen ions (H+) as a function of the H2SO4 concentration. Good agreement between the ionic equilibrium in the CuSO4–H2SO4–H2O system and the results of the electrochemical processes was obtained. In this way, it was shown how this ionic equilibrium can be applied to predict and analyze the solution composition in electrolytic copper deposition processes.

Effect of Current Density and Plating Time on the Morphology of Copper Electrodeposits on an AFM Tip

An attempt was made to electrodeposit copper on a nanosize atomic force microscopy (AFM) tip by varying the magnitude of current densities with plating time and vice versa. Changes in the current density and plating time resulted in significant changes in the morphology of copper deposits on the AFM probe containing the tip. Scanning electron microscopy (SEM) results revealed that a nonuniform layer of copper was formed on the open areas surrounding the tip; however, no copper deposition was observed on the AFM tip in the absence of photoresist poly(methyl methacrylate) (PMMA). The electron-beam lithography technique proved to be a versatile tool for the electrodeposition of copper on the AFM tip in the presence of photoresist PMMA. Copper was electrochemically deposited on the e-beam modified regions of the AFM probe at a current density of with plating times ranging from 300 to 2400 s.

Formation of dish-like holes and a channel structure in electrodeposition of copper under hydrogen co-deposition

Copper electrodeposition from acid sulfate solutions at an overpotential of 1000 mV, which is about 250 mV outside the plateau of the limiting diffusion current density, was examined by the determination of the average current efficiency of hydrogen evolution and by the scanning electron microscopic (SEM) analysis of the morphology of the formed copper deposits. Craters or holes formed due to the attachment hydrogen bubbles were the dominant morphological forms of copper deposits obtained at this overpotential. In dependence of the concentration of Cu (II) ions in the plating solution, the two types of holes or craters were formed. One type of holes is obtained by electrodeposition from a solution with a concentration of Cu (II) ions of 0.075 M CuSO 4 in 0.50 M H 2SO 4, and a honeycomb-like structure was formed from these holes. The other types of holes are formed from a solution with a higher concentration of Cu (II) ions (0.60 M CuSO 4 in 0.50 M H 2SO 4) and the formed holes were dish-like. A mixture of both types of holes was obtained by electrodeposition from 0.30 M CuSO 4 in 0.50 M H 2SO 4. The obtained morphologies of copper deposits are discussed in terms of the effect of hydrogen evolution on the hydrodynamic conditions in the plating solution.