Investigation of molybdate–benzotriazole surface treatment against copper tarnishing

Abstract

The synergistic effect of benzotriazole (BTAH) and molybdate on the inhibition of copper tarnish was studied in this paper. The antitarnish treatment of copper was conducted with BTAH solution containing molybdate. The surface morphology observation and composition analysis were investigated by SEM with energy dispersive X-ray (EDX) spectroscopy. The addition of molybdate improved the protection of BTAH significantly. The BTAH + molybdate treated copper specimen has higher N concentration in its surface. The structure of the protective film was studied by XPS and AES measurements. It was characterized to be a complex of Cu(I)BTA. The antitarnish effect is certified by the formation of the protective Cu(I)BTA film. Molybdate does not participate in the formation of the protective film. The presence of molybdate promotes the passivation of copper. This facilitates the stabilization of the cuprous oxide film, and strengthens the adsorption of BTAH.

Surface characteristics of ruthenium in periodate-based slurry during chemical mechanical polishing

“…7(a) shows the element depth profiles of the ruthenium surface under a pH 6 condition. After 20 min, the Ru atomic concentration increases to greater than 90%, and the film thickness is thereby estimated to about 80 nm [41]. Fig.…”

Self-healing coatings

“…Silyl ester [38,39], silanes [117,[160][161][162], mercapto compounds [149,159], azolesparticularly benzotriazole [163][164][165][166][167] prevention, with some listed in Table 8.2. The key to a successful design is to find a good inhibitor system with the correct solubility.…”

Discoloration Resistance of Electrolytic Copper Foil Following 1,2,3-Benzotriazole Surface Treatment with Sodium Molybdate

“…In XPS analysis ( Figure 6), all of the groups (irrespective of Na 2 MoO 4 content) contained C 1s, N 1s, O 1s, Cu 3d, Cu 3p 1/2, Cu 3s and Cu 2p 1/2 peaks. The C, N, O elements were components of the BTA and the peaks related to Cu-BTA formation [25]. When 1 mM Na 2 MoO 4 was added, Mo-related peaks were not detected in the surface components (binding energy = 228 eV: Mo 3d 5/2, 231 eV: Mo 3d 3/2, Figure 6(b1)), suggesting that Na 2 MoO 4 was involved in the formation of the Cu-BTA film but was not itself part of the chemical bonding [25].…”

“…Increasing the amount of Na 2 MoO 4 (i.e., over 5 mM) did not affect the rate of corrosion, because Na 2 MoO 4 at 0.01 M concentration in the electrolyte represents a critical quantity for stable passivation [32]. The presence of molybdate results in the passivation of copper, which enhances the adsorption of BTA [25]. Moshier et al [33] showed that both the Mo +4 and Mo +6 states is limited by solubility and the molybdate had been reduced during the formation of the passive film.…”

“…The addition of sodium molybdate (Na 2 MoO 4 ) to low-concentration solutions is often used in combination with other inhibitors because it accelerates corrosion resistance due to oxidation [24]. Ramesh [22] reported the rust-inhibition effect for copper by mixing a triazole compound with molybdate but relatively few studies have considered the complex anti-rusting effect of BTA and molybdate [16,25].…”