Determination of the Cu2O Thickness on BTAH-Inhibited Copper by Reconstruction of Auger Electron Spectra.

The influence of the benzotriazole (BTAH) inhibitor on the thickness of the Cu₂O oxide layer formed on Cu immersed in 3% NaCl solution was studied with angle-resolved X-ray photoelectron spectroscopy. The X-ray-induced Auger Cu L₃M_4,5M_4,5 spectra were reconstructed with the Monte Carlo algorithm using the spectra of the basic constituents [Cu(I)BTA, Cu₂O, and Cu] formed on the surface. The relative contributions of the basic constituents to the composite Cu L₃M_4,5M_4,5 spectra measured at different emission angles were then used to estimate the thickness of the Cu₂O oxide layer. The results show that the presence of BTAH substantially reduces the thickness of the Cu₂O oxide layer formed on Cu in chloride media. The average thickness of the Cu₂O layer below the Cu(I)BTA layer is estimated to be 1.3 ± 0.2 nm, whereas the Cu₂O thickness of the noninhibited sample is 2.2 ± 0.3 nm. [ABSTRACT FROM AUTHOR]