Solid-state wetting experiments were carried out to derive the work of adhesion (adhesion energy) of pertinent Cu/liner interfaces via the Young–Dupré equation using contact-angle measurements of the Cu equilibrium crystal shape on Ta and TaNx liners. Four types of liner surfaces were examined: untreated sputtered Ta (uSp-Ta), untreated sputtered TaNx (uSp-TaN), untreated atomic layer deposited (ALD) TaNx (uALD-TaN), and indium surfactant-treated ALD TaNx (tALD-TaN). All Cu-liner stacks were subsequently annealed at 600 °C for 48 h in a forming gas (95% Ar/5% H2) ambient. For Cu/uSp-Ta, the work of adhesion was found to be 2170 mJ/m2, corresponding to an average contact angle of 74°, while for Cu/uSp-TaN, the work of adhesion amounted to 1850 mJ/m2 for an average contact angle of 85°. Alternatively, the work of adhesion for Cu/uALD-TaN was determined to be 1850 mJ/m2, corresponding to an average contact angle of 85°, while for Cu/tALD-TaN, the work of adhesion was 2280 mJ/m2, at an average contact angle of 70°. These findings indicate that the highest degree of surface wetting occurs for the indium surfactant-treated ALD TaNx. It is thus suggested that surfactant treatment causes a reduction in the energy barrier to Cu nucleation, resulting in an enhancement in Cu wetting characteristics and a more uniform concentration of Cu nucleation sites. A critical potential outcome is the formation of atomically smooth Cu-liner interfaces with enhanced adhesion characteristics.

A Focused Ion Beam (FIB) microscope was to locally deposit platinum contacts on Multiwalled Carbon Nanotubes (MWNTs) for resistance and current carrying capability measurements. We have determined the resistivity of these ultra-thin Pt lines and the MWNT-Pt contact resistance to account for contributions to the MWNT measurements. We have studied the effects of secondary mental deposition around the contacts (‘halo’ effect) on the MENT electrical measurements as well as effects of ion beam exposure and possible ways to avoid/minimize them. Transmission Electron Microscopy data was used to evalutate MWNT surface modifications due to ion beam exposure and Pt deposition.

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It is proposed to measure the cross sections of steep-sided etched lines and similar deep surface topography on partially completed silicon integrated circuit wafers using either the backscattered electron (BSE) or the low-loss electron (LLE) image in the scanning electron microscope (SEM). These images contain regions where the collected signal is zero because there is no direct line of sight between the landing point of the electron beam on the specimen and the BSE or LLE detector. It is proposed to use the boundary of such a region in the SEM image as a geometrical line to measure the surface topography. Or alternatively, a shadow can be seen in the distribution of either BSE or LLE with an image-forming detector system. The use of this shadow position on the detector to measure deep surface topography will be demonstrated.