Growth of Pd-Filled Carbon Nanotubes on the Tip of Scanning Probe Microscopy

Abstract

We have synthesized Pd-filled carbon nanotubes (CNTs) oriented perpendicular to Si substrates using a microwave plasma-enhanced chemical vapor deposition (MPECVD) for the application of scanning probe microscopy (SPM) tip. Prior to the CVD growth, Al thin film (10 nm) was coated on the substrate as a buffer layer followed by depositing a5∼40 nm-thick Pd film as a catalyst. The diameter and areal density of CNTs grown depend largely on the initial Pd thickness. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images clearly show that Pd is successfully encapsulated into the CNTs, probably leading to higher conductivity. Using optimum growth conditions, Pd-filled CNTs are successfully grown on the apex of the conventional SPM cantilever.