Evaluation of K₃Fe(CN)₆ on Deposition Behavior and Structure of Electroless Copper Plating

Abstract

Potassium ferricyanide (K 3 Fe(CN) 6) as a stabilizer was used for electroless copper plating in EDTA/THPED dualligands system. The deposition behavior and surface structure of copper layer were studied systematically. The results indicated that the overall deposition process was divided into three regions designated as induction, transitional and stable regions. It was confirmed that K 3 Fe(CN) 6 can delay the fall-off trend of electrode potential, which may be related to the competitive adsorption between Fe(CN) 6 3− with large radius and OH − with small radius on the electrode surface. The addition of K 3 Fe(CN) 6 led to a decrease of 70% in redox current density, which reduced obviously Cu deposition rate. Meanwhile, the decomposition time of electroless solution sharply increased and the reoxidation of Cu(I) ion was effectively inhibited in the presence of K 3 Fe(CN) 6. Metallographic studies of copper layers with and without K 3 Fe(CN) 6 stabilizer revealed that surface structures and fine particle distribution were uniform. The resultant product was high-purity without detectable iron impurities. Moreover, the addition of K 3 Fe(CN) 6 was favorable to the formation of the preferred orientation on (220) crystal plane, and the grain size decreased from 61.5 nm to 40.4 nm with the addition of 50 mg L −1 K 3 Fe(CN) 6 .

Effect of Current Density on Crystallographic Orientation, and Oxidation Behavior of Copper Plated on Aluminum Substrate

“…Jianhong et al investigate K3Fe(CN)6 addition on electro less copper plating. Without K3Fe(CN)6 addition, preferred orientation is seen on (111) plane, and more addition of K3Fe(CN)6 will increase the (022) plane resulting in the preferred orientation of (002) plane [6]. These phenomena are contradictive with our result, the preferred orientation of (111) plane is seen on Cu-3, Cu10, and Cu-40.…”

“…The FWHM of the various sample used to determine the crystallite size of the copper film. Crystallite size can be calculated using the following Debye-Sherrer equation [6], [23].…”

“…The copper layer, prepared by copper deposition on an aluminum substrate, offers many benefits over bulk copper, namely cost advantage [1], [2]. Copper deposition can be achieved by many techniques, such as physical vapor deposition (PVD) [3], chemical vapor deposition (CVD) [4], electroplating [5] and electro less plating [6]. Electroplating one of the easiest to control and cheapest for deposition methods [7].…”

Nickel layers properties produced by electroplating were influenced by spinning permanent magnet

“…Base plating bath Before and after electroplating, a specimen was weighed to determine deposition rate and cathodic current efficiency. The following expression calculated the deposition rate and cathodic current efficiency [12].…”

Magnetic field exposure on electroplating process of ferromagnetic nickel ion on copper substrate

“…All XRD data were refined with high score plus software. The deposition rates were measured with equation 1 [12], a digital scale was used for weighing the samples before and after the electroplating process.…”