Patent ID: 8535504
Filing Date: 2013-09-17
Classification: C25D,G01N

Abstract:
1. A method for determining the concentration of an auxiliary leveler additive in an acid copper electroplating bath also containing a suppressor additive, an anti-suppressor additive and a leveler additive, comprising the steps of: (1) cycling the potential of a rotating disk electrode between a predetermined negative potential limit and a predetermined positive potential limit in the oxygen evolution region positive of 1.9 V vs. SSCE/M in a background electrolyte of the acid copper electroplating bath comprising predetermined concentrations of sulfuric acid (H (2) measuring the current response as the potential of the rotating disk electrode is cycled in step (1) so as to produce a normalization cyclic voltammogram; (3) selecting a baseline current a (I (4) integrating the portion of the current in the normalization voltammogram that is greater than the baseline current so as to determine an A (5) cycling the potential of the rotating disk electrode between the predetermined negative potential limit and the predetermined positive potential limit in a plurality of calibration solutions comprising the background electrolyte and different predetermined concentrations of the auxiliary leveler additive; (6) measuring the current response as the potential of the rotating disk electrode is cycled in step (5) so as to produce a plurality of calibration cyclic voltammograms; (7) integrating the portion of the current in each of the calibration cyclic voltammograms that is greater than the baseline current so as to determine a plurality of A (8) plotting the ratio A (9) cycling the potential of the rotating disk electrode between the predetermined negative potential limit and the predetermined positive potential limit in a measurement solution comprising predetermined volume fractions of the supporting electrolyte and a sample of the acid copper electroplating bath; (10) measuring the current response as the potential of the rotating disk electrode is cycled in step (9) so as to produce a measurement cyclic voltammogram; (11) integrating the portion of the current in the measurement cyclic voltammogram that is greater than the baseline current so as to determine an A (12) comparing the ratio A