Environmentally friendly novel macromolecular leveller imidazole-pentaerythritol glycidyl ether with high electroplating performance

Abstract

In this study, a novel environmentally friendly leveller, imidazole-pentaerythritol glycidyl ether (IMDPGE), which is free of sulfur (S) and other pollutant elements, was developed by chemical synthesis for blind-hole filling in acidic copper electroplating. The chemical structure of IMDPGE was characterized using Fourier transform infrared spectroscopy and mass spectrometry. The molecular properties of IMDPGE were investigated through quantum chemical calculations and molecular dynamics simulations, and its levelling performance was predicted accordingly. The electrochemical characteristics of IMDPGE, as well as its interactions with the accelerator bis-(3-sulfopropyl) disulfide (SPS) and the suppressor propyleneoxide (PO)-ethylene oxide (EO)-propylene oxide (PO), named PEP (EPE), were evaluated using galvanostatic potential transient measurements, cyclic voltammetry and linear scan voltammetry. The results demonstrated that IMDPGE exhibited strong polarization capability, which persisted even in the absence of SPS. Additionally, a kinetically controlled competitive adsorption existed between IMDPGE and SPS, while a synergistic inhibitory effect was observed between IMDPGE and EPE. The blind-hole filling performance of IMDPGE was verified through electroplating experiments. For the optimized EPE-SPS-IMDPGE additive system, a filling rate of 90.7% and a surface copper thickness of 7.7 µm were achieved after electroplating at a current density of 2 A dm–² for 30 minutes.