Accuracy Improvement in Cyclic Voltammetry Stripping Analysis of Thiourea Concentration in Copper Plating Baths. Issue 4 (14th February 2015)

• Record Type: Journal Article
• Authors: Choe, Seunghoe; Kim, Myung Jun; Kim, Kwang Hwan; Kim, Hoe Chul; Song, Jae Chun; Kim, Soo-Kil; Kim, Jae Jeong
• Is Part Of: Journal of the Electrochemical Society. Volume 162:Issue 4(2015)
• Page Start: H294
• Page End: H300
• Publication Date: 2015-02-14
• Subjects: Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0051506jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Cyclic voltammetry stripping (CVS) has been regarded as a powerful tool for monitoring the concentrations of organic additives in plating baths. In this study, the dilution titration (DT) method of CVS was modified to improve the measurement accuracy of thiourea (TU) concentrations in Cu plating baths. The conventional DT-CVS method cannot guarantee high accuracy because the electrochemical behavior of TU is concentration and potential dependent, which can cause disturbances in the response signals. In this study, by adding polyethylene glycol (PEG) as an organic additive, the undesirable electrochemical behavior of TU was suppressed and the accuracy of DT-CVS was greatly improved. Using the improved method, the concentrations of TU and its derivatives in the plating bath were measured. The errors between the real and measured concentrations were reduced from 15.0%, 36.0%, and 15.0% using the conventional DT-CVS method to within 3.00%, 6.00%, and 6.00% for TU, N-ethyl thiourea, and N ′, N-diethyl thiourea, respectively, using the improved method.