Effect of an Alkoxyliertes Beta Naphthol on Cu Electrodeposition for Application to Low‐Resistivity Cu Interconnects

Cu thin films were electrodeposited using electrolytes containing alkoxyliertes beta naphthol (ABN) as an organic additive, which shows a strong suppressing effect similar to PEG10000. The surface roughness of Cu thin film decreased, while the grain size remained unchanged with increasing ABN concentration. Consequently, the resistivity of Cu thin film was reduced by 41% compared to Cu thin film electrodeposited using pure electrolyte. In addition, the void free interconnect wire was fabricated by filling of 70‐nm wide trench using only ABN, without the help of any accelerator or leveler. Gap‐fill of 70‐nm‐wide Cu interconnects for various concentrations of an additive, Alkoxyliertes Beta Naphthol.