Patent attributes
A phase feedback AFM (atomic force microscope) and method for the phase feedback AFM. A cantilever is driven to oscillate at a constant frequency close to the resonance frequency of the cantilever by a driving signal. The distance between the probe and the sample is controlled such that the phase difference between the driving signal and a cantilever deflection signal indicating deflections of the cantilever is kept constant. The phase feedback AFM has an amplifier-controller for receiving the cantilever deflection signal, the output from an oscillator for driving the cantilever into oscillation, and a signal representing a reference amplitude of oscillation of the cantilever. The phase feedback AFM further includes a feedback circuit which receives the output from the amplifier-controller which controls the cantilever deflection signal to a preset amplitude.
