Quinacridone skeleton as a promising efficient leveler for smooth and conformal copper electrodeposition

Abstract Superconformal copper electrodeposition of nano-micro printed circuit board (PCB) is of prime importance in microelectronics manufacturing. It is very challenging and still remains deficient exploration to fully realize efficient conformal electrodeposition in the emerging organic additives. Herein, a family of quinacridone (QA) derivatives bearing quaternary ammonium groups were synthesized via two steps with high yields. These compounds were functionalized as promising levelers for superconformal Cu deposition for the first time. Alkyl chains and aryl groups tuning strategies were performed to precisely synthesize and optimize these QA levelers. The optimal leveling agent (DCQA-C8-QAS) and electrodeposition formula were obtained through electrochemical measurements, theoretical calculations and through-hole (TH) electrodeposition experiments. The superior leveling behavior of DCQA-C8-QAS was mainly attributed to the strong interaction and adhesion ability towards copper surface, which were verified by X-ray photoelectron spectra (XPS), atomic force microscope (AFM) and contact angle detection (CA).