title: Advanced fabrication process for combined atomic force-scanning electrochemical microscopy (AFM-SECM) probes.
abstract: An advanced software-controlled focused ion beam (FIB) patterning process for the fabrication of combined atomic force-scanning electrochemical microscopy (AFM-SECM) probes is reported. FIB milling is a standard process in scanning probe microscopy (SPM) for specialized SPM probe fabrication. For AFM-SECM, milling of bifunctional probes usually requires several milling steps. Milling such complex multi-layer/multi-material structures using a single milling routine leads to significantly reduced fabrication times and costs. Based on an advanced patterning routine, a semi-automated FIB milling routine for fabricating combined AFM-SECM probes with high reproducibility is presented with future potential for processing at a wafer level. The fabricated bifunctional probes were electrochemically characterized using cyclic voltammetry, and their performance for AFM-SECM imaging experiments was tested. Different insulation materials (Parylene-C and SixNy) have been evaluated with respect to facilitating the overall milling process, the influence on the electrochemical behavior and the long-term stability of the obtained probes. Furthermore, the influence of material composition and layer sequence to the overall shape and properties of the combined probes were evaluated.
authors.affiliation: Institute of Analytical and Bioanalytical Chemistry, University of Ulm, Ulm, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Eifert
authors.affiliation: Institute of Analytical and Bioanalytical Chemistry, University of Ulm, Ulm, Germany.
authors.forename: Boris
authors.initials: B
authors.lastname: Mizaikoff
authors.affiliation: Institute of Analytical and Bioanalytical Chemistry, University of Ulm, Ulm, Germany. Electronic address: christine.kranz@uni-ulm.de.
authors.forename: Christine
authors.initials: C
authors.lastname: Kranz
keywords: AFM tip-integrated electrode; AFM-SECM; Atomic force-scanning electrochemical microscopy; FIB milling; Steady-state current simulation