Mechanical and electronic characteristics of scanning probe microscopy probes based on coaxial palladium nanowire/carbon nanotube hybrid structures

Abstract

The authors present the mechanical and electronic characterization of a novel kind of scanning probe microscopy probe fabricated by the microwave plasma-enhanced chemical vapor deposition growth of carbon nanotubes using a catalytic palladium film deposited only near the apices of commercial tapping mode atomic force microscopy (AFM) cantilevers with the use of a newly developed controlled-area electroplating method. This process is shown to result in the growth of coaxial palladium nanowire/carbon nanotube composite structures (PdNWCNTs). The authors demonstrate that neither the cantilever quality factor nor the cantilever spring constant is significantly degraded by PdNWCNT growth, and show that PdNWCNT probes are adequate for standard tapping mode AFM imaging. Low resistance Ohmic contact between PdNWCNT probes and metal surfaces is demonstrated. Importantly, repeated surface contact and current flow is shown to not damage the PdNWCNTs, indicating that the probes are appropriate for multiprobe conductivity measurements. A brief overview of the fabrication process is also provided.