Electrical Properties of Single Carbon Nanofibers Grown on Tips of Scanning Probe Microscope Cantilevers by Ion Irradiation

The Ar ion irradiation method has a high potential for the batch fabrication of single carbon nanofibers (CNFs) onto the tip of cantilevers, and is known to have excellent mechanical characteristics. In this study, we analyzed the electrical properties of ion-induced CNFs. For this purpose, current–voltage (I–V) properties were measured using an atomic force microscope (AFM). Commercial-type Si probes (without CNFs) showed a typical diode characteristic. By contrast, Si probes with ioninduced CNFs (CNF probes) showed a metallic characteristic similar to that of Pt-coated Si probes. The Pt-coated Si probes were completely damaged at an applied voltage of 5V, whereas the CNF probes retained their metallic I–V characteristic and no increase in resistance was detected even at 10V. Electrical properties were further investigated by scanning spreading resistance microscopy (SSRM) measurements. Compared with electroconductive diamond probes, which are commonly used for SSRM measurements, CNF probes were superior in the sensitivity for measuring surface roughness owing to both the small radial curvature of the tip and a high aspect ratio. Thus, it was believed that the CNF probes are quite promising as electroconductive probes. [DOI: 10.1143/JJAP.46.5607]