Influence of carbon nanotubes on the electrodeposition of copper interconnects

Abstract

The electrochemistry of the co-deposition of Cu with carbon nanotube, CNTs is studied by voltammetry and chronoamperometry experiments. Electrochemical data shows CNTs have a slightly accelerating influence on the Cu electrodeposition when nafion was added in the bath as a surfactant of CNTs. The amount of CNTs in the deposit is up to 2% by weight. Kinetic data confirms that the addition of CNTs to the Cu baths increases the Cu exchange current density and decreases the equilibrium potential value. The electrical resistivity results show that at room temperature the resistivity of Cu/CNT composites film (2.47 μΩ-cm) is close to the resistivity of Cu film (2.15 μΩ-cm). A clear decrease of sample resistivity is observed with increasing anneal temperature upto 315ºC. The resistivity also increases when the concentration of CNTs is increased from 10 mg/l to 100 mg/l in the bath.