Nanoprobes for near-field optical microscopy manufactured by substitute-sheath etching and hollow cathode sputtering

This article reports a new approach for probe manufacturing, which is the key component in scanning near-field optical microscope (SNOM). The wet-etching process, to create the tip at the apex of a tapered fiber, has been optimized. Typical tip features are short tapers, large cone angles (30 degrees), and very small diameters (< 50 nm). Next process steps are performed in an original arrangement of plasma device, based on a modified hollow cathode discharge. It is used for both, to remove the dust particles or the etching residues from the tip surface and to coat the tapered region with a metallic ultrathin and compact film. To complete the probe's fabrication, the tips are opened by dry electrolytic erosion. These probes have been successfully tested for SNOM applications. (c) 2006 American Institute of Physics.