Effect of DL-alanine as an auxiliary complexing agent in TSV copper film CMP

The quality of the chemical mechanical polishing (CMP) process of the reactive Through Silicon Via (TSV) copper (Cu) film depends in large part on the slurry's planarization characteristic. Due to their non-polluting and excellent performance qualities, amino acid chemical additives have been extensively employed in the semiconductor and microelectronics sectors for the development of novel CMP slurries. In this investigation, the slurries used to create the TSV copper film contained DL-alanine as a key chemical constituent. It was discovered through CMP tests, UV–Vis spectroscopy, X-ray photoelectron spectroscopy, and electrochemical measurements that alanine could interact in a specific ratio with copper ions to form stable water-soluble Cu-alanine complexes, which could hasten the chemical dissolution of copper surface during CMP process. Additionally alanine was utilized as a supplementary complexing agent in glycine-based Cu film slurries, which resulted in a high removal rate, low static etching rate, and excellent surface quality. Graphical abstract