Comparison of Bottom‐up Filling in Electroless Plating with an Addition of PEG, PPG and EPE

Abstract

The bottom-up filling capabilities of electroless copper plating bath with an addition of additives, such as polyethylene glycol (PEG), polypropylene glycol (PPG) and triblock copolymers of PEG and PPG with ethylene oxide terminal blocks termed EPE, were investigated by the cross-sectional scanning electron microscopy (SEM) observation of sub-micrometer trenches. Though three additives had inhibition for electroless copper deposition, the suppression degrees of three additives were different. EPE-2000 had the strongest suppression for electroless copper deposition, and the suppression of PEG-2000 was the weakest. The bottom-up filling capability of electroless copper was investigated in a plating bath containing different additives with the concentration of 2.0 mg/L. The cross-sectional SEM observation indicated the trenches with the width of 280 nm and the depth of 475 nm were all completely filled by the plating bath with an addition of EPE-2000, but the trenches were not completely filled by the plating bath with an addition of PEG-2000 or PPG-2000, and some voids appeared. Linear sweep voltammetry measurement indicated that three additives all inhibited the cathodic reduction reaction and the anodic oxidation reaction, and the inhibition of EPE-2000 was the strongest among three additives, which agreed with that of the deposition rate of electroless copper. Significant differences in surface roughness of deposited copper film were observed by UV-visible near-infrared for different suppressors, and the bright and smooth of deposited copper film were in accordance with the inhibition of three additives.

Electroless Plating of Palladium Membranes on Porous Substrates for Hydrogen Separation and the Effects of Process Factors on Plating Rate and Efficiency: A Review

“…But the phenomenon is only at low concentrations because at concentrations above 2 mg/l of 2 MBT, the plating rate begins to reduce steadily [21]. All the organic compounds investigated by this group exhibited similar trend which was also reported by Yang, Z et al (2011) [33] in their investigation on the addition of Polyethylene glycol (PEG), Polypropylene glycol (PPG) and ethylene oxide terminal blocks termed EPE. Pizzi, et al (2008) [34] also discovered that the plating rate decreases with an increase in the concentration of the additive up to 2 mg/l.…”

Non-sintering Preparation of Copper (II) Oxide Powder for Electroplating via 2-step Chemical Reaction

“…In this reported study, copper (II) oxide was produced from a copper (II) chloride solution via a twostep chemical reaction. Basic copper carbonate was synthesized by reacting copper chloride with sodium carbonate (Na 2 CO 3 , 99 wt.%, OCI product) as shown in Equations (1) and (2), which formed the first reaction step in the process. Copper oxide (CuO) was then synthesized by reacting copper carbonate and sodium hydroxide as shown in equation (3).…”

“…The copper electroplating processes generally requires virgin plating solutions composed of copper sulfate, chloride compounds, and brighteners, as well as a soluble copper ball anode containing 0.04-0.06% phosphate to supply the Cu 2+ makeup cations to the solution. Recently, however, sludge emanating from phosphorous impurities and difficulties in the control of the copper ion concentration in the plating bath have forced the replacement of the copper ball with an insoluble anode together with a copper (II) oxide solution as the copper source in the plating process [1][2][3]. Copper (II) oxide facilitates the generation of fine patterns and fine-hole plating by reducing the surface tension of the plating bath.…”

Improvement of plating uniformity for copper patterns of IC substrate with multi-physics coupling simulation

“…The secondary current distribution based on electrochemical adopt pulse waveform current was another way to refine uniformity (Nikolić and Branković, 2010). The tertiary current distribution was influenced by additives (Cao et al , 2013; Dow et al , 2009; Huang et al , 2012; Kreider, 2012; Kudelski, 2003; Mcfadden et al , 2003; Yang et al , 2011). Moreover, auxiliary cathode (AC) is an important impact factor during bottom-up plating of IC substrate (Tan and Lim, 2003).…”