Calculation of the current density distribution of submicron copper electroplating based on uneven adsorption of poly(ethylene glycol)

Abstract

Uneven adsorption of polyethylene glycol (PEG) along a submicron feature enabling the occurrence of void-free deposition has been identified and we have developed a simplified 1-D model to explain the phenomenon based on the distribution of hydrodynamic driving force along the trench depth. We also verified this new model based on the uneven PEG adsorption via an electrochemical quartz crystal microbalance study. The model shows that with only moderate PEG concentration, void-free deposition can be realized. Some parameters used in the modeling were developed from chronopotentiometry and rotating disc electrode experiments.

Evaluating the Filling Performance of a Copper Plating Formula Using a Simple Galvanostat Method

“…In particular, the synergistic inhibition effect of a suppressor with a leveler is accessible to the forced convection. Wu et al 16 reported that the coverage of PEG on a copper surface is a function of the Reynolds number. Furthermore, it was reported that JGB can only effectively exert its inhibiting effect on copper electrodeposition in the presence of PEG.…”

Leveling of Microvias by Electroplating for Wafer Level Packaging

“…For diameters of several tens of µm, a molecular weight of 8000 had the best efficiency in the investigated diameter range. The coverage of PEG on copper surface is a function of the Reynolds number (15). Furthermore, among four common levelers, Janus Green B (JGB) induces the highest overpotential drop observed as the difference between two galvanostatic measurements performed at slow and fast rotation speed of the working electrode and therefore a good filling performance is achieved (16,17).…”