Quantitative measurement of submicrometre electrical conductivity

Electrical conductivity of a 99.999% aluminium wire with a 400 nm width and a 350 nm thickness was measured using the four-point atomic force microscope (AFM) technique. This technique is a combination of the principles of the four-point probe method and standard AFM. The equipment is capable of simultaneously measuring both surface topography and local electrical conductivity. Experiments show the microprobe to be mechanically flexible and robust. The repeatability of conductivity measurements indicates that this four-point AFM probe could be used for fast in situ characterization of local electrical properties of nanocircuits and nanodevices.