Copper Bottom-up Deposition by Breakdown of PEG-Cl Inhibition

摘要

Copper bottom-up deposition in 200 nm trenches by an acid-copper sulfate with only two additives [poly (ethylene glycol) (PEG) and Cl~-] is achieved. The inhibiting effect of electrodeposition by PEG is strongly related to Cl~- Concentration. Secondary-ion mass spectroscopy measurements show that Cl~- is consumed in the electroplating process. The explanation of bottom-up deposition realized in copper superfilling, in which the decrease of Cl~- concentration causes rapid electrodeposition on trench bottoms, is verified experimentally.