cantilever excitation method and atomic force microscope in an atomic force microscope

摘要

PROBLEM TO BE SOLVED: To provide a spurious-free cantilever excitation method capable of measuring a sample with high accuracy when the sample immersed in a liquid is measured in spite of a simple configuration and low cost.;SOLUTION: An excitation voltage generated by amplitude modulating a carrier wave signal of a high frequency wave is applied between a thin metallic film 5a formed on a back surface of a cantilever 5 and a counter electrode 9 formed on an undersurface of a transparent body 4a of a pedestal portion 4 to which the cantilever 5 is fixed. Since an electric double layer capacity formed on an interfacial surface between the cantilever 5 and a liquid 8 undergoes dielectric relaxation, force by interfacial tension effect becomes a negligible degree and action by electrostatic force becomes dominant. Accordingly, an excitation spectrum becomes close to an ideal harmonic oscillator model and, in a frequency region of which a frequency is sufficiently lower than a resonant frequency, the amplitude and a phase have flat characteristics not depending on frequencies.;COPYRIGHT: (C)2013,JPO&INPIT