An electrostatic force probe for surface profile measurement in noncontact condition

A scanning probe microscope with an electrostatic force probe has been introduced for the dimensional measurement of the surface profile measurement. Since the intensity of the electrostatic force is strongly depended on the distance between a probe and the sample surface, the electrostatic force probe can be used for the measurement of the surface profile in non contact condition. In order to detect the electrostatic force between the probe tip and the sample surface, a method of the frequency modulation AFM has been employed. When the bias voltage is applied between the probe and the surface, the resonance frequency of the probe oscillation is shifted owing to the electrostatic force. In this paper, the basic characteristics of the electrostatic probe are investigated, experimentally. And then, the absolute distance between the probe tip and the sample surface is calculated by using the differences of the frequency shift of the probe. Finally, the measurement of surface profile is demonstrated in non-contact condition by utilizing the developed electrostatic force probe.