An EQCM Study of the Electrochemical Copper(II)/Copper(I)/Copper System in the Presence of PEG and Chloride Ions

Doblhofer, Karl; Wasle, Sabine; Soares, David Mendez; Weil, K. G.; Ertl, G.

doi:10.1149/1.1602083

Cited by 79 publications

(83 citation statements)

References 39 publications

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“…Higher Cl concentrations lead to precipitation of CuCl salt. 6 Voltammetric experiments in PEG solutions with Cl − concentrations significantly lower than 1 mM were reported by Jovic and Jovic, and are displayed in Fig. 1.…”

Section: Part Of the Chemical Engineering Commonsmentioning

confidence: 59%

Role of Chloride Ions in Suppression of Copper Electrodeposition by Polyethylene Glycol

Hebert

2005

J. Electrochem. Soc.

100

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Chloride ions and polyethylene glycol ͑PEG͒ are used together as additives to copper damascene electroplating baths, in which they suppress deposition. When the Cl − concentration is lower than the order of 1 mM, suppression abruptly breaks down below a critical potential, around which hysteresis between active and inhibited deposition is observed. A mathematical model is presented which successfully predicts the observed Cl − concentration-dependent breakdown of PEG suppression and currentpotential hysteresis. The model assumes that adsorbed Cl − ions are involved in binding of PEG to the Cu surface, and that these ions are incorporated in the deposited film. The expressions for Cl − incorporation and adsorption are consistent with experimental measurements of Cl in deposits. Hysteresis was found to depend on the high sensitivity of polymer surface coverage to the concentration of adsorbed Cl − ions, possibly because each PEG molecule has a small number of binding sites to the surface.

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Section: Part Of the Chemical Engineering Commonsmentioning

confidence: 59%

Role of Chloride Ions in Suppression of Copper Electrodeposition by Polyethylene Glycol

Hebert

2005

J. Electrochem. Soc.

100

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“…When both PEG and Cl − are present, a surface layer forms on the copper electrode that constitutes a barrier for charge transfer [2][3][4]. Healy et al suggested that the polymer can adsorb in two different ways.…”

Section: Introductionmentioning

confidence: 99%

Effect of additives on Cu electrodeposits: electrochemical study coupled with EQCM measurements

Eyraud¹,

Kologo²,

Bonou³

et al. 2006

J Electroceram

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The effect of polyethylene glycol (PEG) and chloride ions on Cu electrodeposition mechanism is investigated. Using blank electrolyte, electrochemical measurements show that PEG adsorbs more or less on the electrode surface depending on the nature of this surface (copper, gold). Alternative current techniques and electrochemical quartz crystal microbalance (EQCM) experiments are performed at open circuit and under polarisation. They show that the PEG adsorption on the Cu electrode is weak at open circuit, but increases under polarisation. In complementary EQCM tests made on Au and on electrodeposited Cu, we conclude that the H 2 gas production reduces the apparent mass of the gold surface. In contrary on Cu, H 2 entrapped in the Cu deposit increases the mass. In all cases, there is an important mass hysteresis. Whatever the substrate, the addition of PEG + Cl − to solution has a beneficial effect by reducing this hysteresis due to the H 2 production. For Cu electrolytes, the PEG addition to solution has little effect, while the simultaneous PEG + Cl − addition inhibits both the Cu 2+ reduction current and the mass increase. Atomic force microscopy (AFM) images made on the deposits confirm the beneficial effect of the two additives in solution.

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“…The synergy of these additives stemmed from the adsorptive and transport characteristics of chloride ions and from the competitive interaction between the suppressor, accelerator, and leveler. 13,[35][36][37][38][39][40][41][42][43][44][45][46][47] In order to further analysis the function of Polyquaternium-2 in TH electroplating process, the addition sequence was changed again (the addition sequence followed the description in Table 1) and the result was shown in Fig. 9.…”

Section: Resultsmentioning

confidence: 99%

Polyquaternium-2: A New Levelling Agent for Copper Electroplating from Acidic Sulphate Bath

Chen

Wang

et al. 2016

Electrochemistry

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Poly[bis(2-chloroethyl)ether-alt-1,3-bis [3-(dimethylamino)propyl]urea] (Polyquaternium-2) was employed as a leveler in the through-hole (TH) electroplating experiments from an acidic sulphate bath. The interaction between Polyquaternium-2 and copper surface was investigated using Field Emission Scanning Electronic Microscope (FE-SEM) and X-ray Photoelectron Spectra (XPS). The electrochemical behavior of Polyquaternium-2 and its interaction with other additives, such as a suppressor and an accelerator were characterized using rotating disk electrode. Polyquaternium-2 could absorb on copper surface to form an adsorption layer and inhibit the copper electrodeposition. As shown in the TH electroplating experiments, a copper deposit with uniform thickness was obtained when 0.17 µmol/L Polyquaternium-2 was added. The addition of Polyquaternium-2 could also increase the cathodic polarization, which is attributed to the adsorption of Polyquaternium-2 on the cathode in the process of TH electroplating. The results indicate that Polyquaternium-2 is an effective leveler used for TH electroplating, having a good synergy with SPS, PEG and Cl − .

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An EQCM Study of the Electrochemical Copper(II)/Copper(I)/Copper System in the Presence of PEG and Chloride Ions

Cited by 79 publications

References 39 publications

Role of Chloride Ions in Suppression of Copper Electrodeposition by Polyethylene Glycol

Role of Chloride Ions in Suppression of Copper Electrodeposition by Polyethylene Glycol

Effect of additives on Cu electrodeposits: electrochemical study coupled with EQCM measurements

Polyquaternium-2: A New Levelling Agent for Copper Electroplating from Acidic Sulphate Bath

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