In-depth research on azole corrosion inhibitors - effect of N atoms position and quantity on copper corrosion inhibition performance in alkaline environments: Experimental evaluation and theoretical analysis

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2024-10, Vol.698, p.134624, Article 134624
• Main Authors: Liu, Renhao, Han, Xinyu, Tan, Baimei, Li, Wei, Wang, Fangyuan, Wang, Xiaolong, Zhao, Jiadong, Zhao, Xinyu
• Format: Article
• Language: English
• Subjects: Adsorption configuration; Copper; Corrosion inhibitor; Density functional theory; Nitrogen-atoms
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2024.134624

Copper's superior electrical properties make it ideal for multi-layer interconnections in integrated circuits. Chemical mechanical polishing (CMP) is the main method for achieving copper wiring flatness. However, copper is susceptible to corrosion in glycine-based alkaline polishing solutions. This study examines benzimidazole, indazole, and benzotriazole as corrosion inhibitors for copper in an alkaline environment (pH=9), focusing on the impact of nitrogen atom arrangement on inhibition efficiency. Through electrochemical, contact angle, static corrosion, and surface characterization tests, it's demonstrated that these inhibitors protect copper surfaces effectively. The adsorption of these inhibitors follows the Langmuir equation with a mixed adsorption mode. X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy tests, and density functional theory calculations elucidate the adsorption configuration and corrosion inhibition mechanism. The scope of this research extends beyond merely analyzing the performance of the three corrosion inhibitors; more importantly, it has yielded novel insights that are broadly applicable to the field of corrosion inhibitors. The findings are as follows: 1. The coupled structure of dinitrogen and trinitrogen facilitates charge accumulation, manifesting as the formation of additional Cu-N bonds, which prevents desorption; 2. The multi-nitrogen coupled structures provide sites for the formation of intermolecular hydrogen bonds, which is essential for the establishment of an orderly and dense passivation layer. It is expected that this study will provide valuable insights into the development and design of new and efficient copper corrosion inhibitors. [Display omitted] •Adding corrosion inhibitors is an effective method to prevent excessive corrosion of copper wiring.•The mechanism of corrosion inhibitors is to adsorb on metal surfaces and isolate corrosive media.•The position of N atoms in corrosion inhibitors are crucial for improving their corrosion inhibition performance.•N atoms can promote the formation of more Cu-N and enhance the stability of the passivation layer.