Copper electrodeposition in sulphate solutions in the presence of benzotriazole

Abstract

DC and pulse plating of copper in acidic sulphate solutions containing benzotriazole (BTA) has been studied. When BTA is the only additive present, it generally has a stronger effect than the plating mode and significantly enhances deposit morphology and surface brightness over that produced in additive-free solutions. XPS and voltammetry analyses indicate that BTA is present at the surface of the deposit, but not through the entire coating, and does not become depleted within the solution over the course of plating. This may help explain why the initial surface smoothness and brightness is maintained as the coating grows beyond 5 lm thick. Plating mode does have a strong effect on deposit morphology under specific conditions. Pulse current plating at low frequency (50 Hz) and low duty cycle (20%) produces deposits with poorer quality than that obtained by DC plating. Pulse reverse plating yields very coarse and dull coatings when the frequency is low enough for metal dissolution to occur during the reverse time. Regardless of the plating mode, the addition of Cl ) eliminates most of the beneficial effects of BTA and leads to very rough and dull deposits. The observed effects are discussed in light of previous research on the electrodeposition and corrosion of the Cu-BTA and Cu-BTA-Cl systems.

Experimental Design and Response Surface Analysis as Available Tools for Statistical Modeling and Optimization of Electrodeposition Processes

“…For example, Healy & Pletcher (1998a, 1998b have shown that the studied additives (Cl -, polyethylene glycol, and 4,5-dithiaoctane-l,8-disulfonic acid) adsorbed on the electrode at different deposition potentials and stirring speeds influences in the copper reduction mechanism. Similar results were observed by Bozzini et al (2006) and Tantavichet & Pritzker (2006), who studied the effects of polyethylene glycol and benzotriazole, respectively. Nayana et al (2011) have investigated the influence of additives on the morphology and brightness of nanocrystalline zinc electrodeposited from an acid sulfate bath.…”

Inhibition of copper local depassivation in alkaline media with oxygen-containing anions

“…On the one hand, this film [Cu(I)-BTA] is a physical barrier screening the metal surface from the corrosive ions present in solution, and on the other hand, it binds copper atoms, preventing anodic dissolution and decreasing the electrical conductivity of the surface layer [7]. The following reactions [7][8][9][10] …”

Kinetics of corrosion inhibition of benzotriazole to copper in 3.5% NaCl

“…Benzotriazole (C 6 H 5 N 3 , BTAH) has been extensively studied as an inhibitor for the corrosion of copper and many of its alloys [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16], for dezincification of brass [17,18], and as an additive in the etching [19], electrodeposition [20][21][22], and in the chemical mechanical polishing of copper [23][24][25]. It has also been reported to inhibit the corrosion of iron [26][27][28], cobalt [29], zinc [30], and nickel [28] and to enhance the resistance of tin bronze to oxidation in air up to 500 8C [31].…”