Fast atom bombardment onto vertically aligned multi-walled carbon nanotube bumps to achieve low interconnect resistance with Au layer

Bump-shaped vertically aligned multi-walled carbon nanotubes (MWNTs) were bonded to a Au substrate by a surface activated bonding method using Ar fast atom bombardment (FAB). After carrying out Ar-FAB for 1200 s at a bonding load of 0.74 MPa, the interconnect resistance reduced to 1/1000 of the original resistance. The lowest resistance of 5.2 Ω was achieved for the bonded specimens. Torn graphite layers were observed in the MWNT that was processed by Ar-FAB for 2400 s, and the ratio of the G-band to the D-band in the Raman spectra indicated that the peaks attributable to the defects in the carbon nanotubes increased in response to the Ar-FAB process. These findings indicate that the torn graphite layers were exposed and were in contact with the Au layer, which caused the conductivity path between MWNTs and Au substrates to increase.