Structure modification of M-AFM probe for the measurement of local conductivity

In order to realize the evaluation of electrical properties of materials in nanometer scale, a method to measure the local conductivity of materials was demonstrated. A microwave atomic force microscope (M-AFM) probe which can propagate and emit microwave signals was fabricated. An open structure of a waveguide at the tip of the probe was introduced by focused ion beam fabrication. The M-AFM combined a network analyzer and an AFM was used to measure a sample. The amplitude and phase of the reflection coefficient of the microwave signals were measured, thereby the electrical conductivities of metallic materials were determined. The conductivity obtained by this method is agreement well with that measured by a high-frequency conductometry.