Synthesis and mechanism of quaternary ammonium salts based on porphyrin as high-performance copper levelers

Abstract

The molecular structure and energy distribution of organic compounds have a great influence on their adsorption capacity on the metal surface. However, there are still insufficient researches on the influence of energy distribution on adsorption properties of organic molecules. Herein, a family of porphyrin derivatives (TPyP-Et, TPyP-Oct, TPyP-Bn and TPyP-Al) bearing quaternary ammonium groups were synthesized for the first time as promising levelers for through-hole copper electrodeposition. Electrochemical tests revealed that all four TPyP derivatives displayed enhanced electrochemical properties. Theoretical calculations and molecular dynamics simulations were carried out to investigate the physisorption capacity and chemical reaction activity of the TPyP molecules, as well as the adsorption capacity on the surface of the copper layer. Through optical and scanning electron microscopy as well as X-ray diffractometry, it was demonstrated that TPyP molecules are effective electroplating levelers. TPyP-Oct, with its longer carbon chain substituent, exhibited superior hole-filling performance in practical PCB experiments among the four compounds. This study expandes the application range of porphyrin compounds, analyzes the influence of organic molecular adsorption properties in copper electrodeposition, and provides theoretical guidance for the future study of organic compounds adsorbed on metal surfaces.