Atomic resolution force imaging through the static deflection of the cantilever in simultaneous Scanning Tunneling/Atomic Force Microscopy

Abstract

We report simultaneous Force -static deflection of the cantilever-, Force Gradient and Scanning Tunneling topography images of Si(111)(7 × 7) surface using an off-resonance small amplitude non-contact atomic force microscopy technique with improved force sensitivity. The signal-to-noise ratio of the fiber interferometer used to detect the deflections of the cantilever was improved by applying an RF-modulation into the diode laser, which suppresses the noise in the laser. The measured sensitivity of ∼20 fm/√Hz allows us to obtain atom resolved images of the surface in static deflection of the cantilever, simultaneously with the other imaging channels.