**Acknowledgements**

in Cu/MWCNT composites is expected to be between the resistance value of Cu (284 Ω) and MWCNT (hundreds kΩ). The resistance of the line filled with Cu/CNTs could be improved

> **-0.015 -0.01 -0.005 0 0.005 0.01 0.015 Voltage (V)**

**Figure 12.** Current vs. voltage curve of the 110 nm line width which was filled with electrodeposited Cu/MWCNT

In this chapter we have reported the influence of surfactants on the properties of Cu/CNT composites on Si substrates. Cu/CNTs composite films were co-deposited by electrodeposi‐ tion. Before electrodeposition, CNTs were dispersed by a suitable surfactant. Electrochemi‐ cal data shows that nafion or SDS accelerates the co-deposition where as CTAB suppresses the deposition. Nafion and SDS surfactants result in a relatively smooth deposit whereas CTAB surfactant leads to rougher deposition of the composite. The amount of CNTs in the deposit was up to 2 % by weight using different surfactants and different length/diameter of CNTs. Our electrical analysis showed that for Cu/CNT composite samples maintained at room temperature, the resistivity over time did not change significantly. The electrical resis‐ tivity results also showed that at room temperature the resistivity of the Cu/CNT compo‐ sites film (2.43 µΩ cm) is close to the resistivity of Cu film (2.17 µΩ cm) when nafion was used in the bath to disperse the CNTs. The resistivity of Cu/CNTs film was higher when CTAB or SDS were used instead of nafion as a surfactant. The electrical resistivity results showed that at room temperature the resistivity increased 10% when the concentration of CNT in the bath was increased from 10 mg/l to 100 mg/l. A clear decrease of sample resistiv‐ ity of composite films was observed with increasing annealing temperature. Cu/CNT com‐ posites deposited at a test structure with submicron lines and vias with Cu/CNT composites was only possible from the nafion surfactant containing damascene. The electrical measure‐ ment of 110 nm line width filled with Cu/MWCNT showed that the I-V curves of the Cu/ MWCNT deposited line was linear and the resistance value was 29.7 kΩ which was signifi‐ cantly higher that the resistance value of Cu (284 Ω) deposited. Improvements on these val‐

composite. The concentrations of nafion and MWCNTs in the bath were 0.5% and 50 mg/l respectively.

by using SWCNT instead of the MWCNTs used in this composite.

388 Syntheses and Applications of Carbon Nanotubes and Their Composites

**-0.40 -0.30 -0.20 -0.10 0.00 0.10 0.20 0.30 0.40**

**Current (**m**A)**

**6. Conclusion**

This research was supported by the Irish Research Council for Science, Engineering and Technology (IRCSET) postgraduate scholarship Enterprise Partnership scheme in collabora‐ tion with Intel Ireland Ltd., funded under the National Development Plan.
