Fabrication of Coaxial and Triaxial Atomic Force Microscope Imaging Probes

Abstract

Herein, we detail the fabrication of atomic force microscope (AFM) probes that have two and three coaxial electrodes at their tips. This fabrication strategy leverages the availability of conductive AFM probes and encompasses a general method for processing their complex and delicate structure through the deposition of insulating and conductive layers by shadow masked chemical and physical vapor deposition, respectively. Focused ion beam milling is used to expose the two electrode (coaxial) or three electrode (triaxial) structures at the tip of the AFM probe. Finally, we discuss new imaging modalities enabled by these probes including electrically-driven contact resonance imaging for nanoscale mechanical characterization, imaging the local dielectric constant by quantifying the dielectrophoretic force, and trapping functional particles at the tip of a probe using dielectrophoresis. These imaging techniques illustrate the generality and utility of this fabrication approach and suggest that such probes could be widely applied to image many nanoscale materials.