Micromachined AFM transducer with differential capacitive read-out

A differential capacitive atomic force microscope (AFM) transducer with integrated tip for use in ultra-high vacuum is presented. It is fabricated by the dissolved wafer technique with multiple etch stop using highly boron-doped epitaxial layers. The tip is fabricated using anisotropic etching and radii of curvature of the order of 60 nm were measured. Measured sensitivities agree well with the presented model.