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In this paper we present the application of cantilever based sensors combining scanning force microscopy (SFM) and scanning near-field optical microscopy (SNOM). Microstructure technology processes are employed to fabricate probes with reproducible mechanical and optical properties for both SFM and SNOM applications. The cantilever probe allows simultaneous measurement of the sample topography and the optical transmission of samples with high lateral resolution. The probe consists of a hollow metal tip integrated in a conventional silicon cantilever. The pyramidal tip has at its apex an aperture of sub-wavelength dimensions which is used as a confined light source. Because the tip opening angle is 70.5 • the extent of the tapering region is in the order of a quarter wavelength, which improves the optical transmission efficiency and avoids thermal effects.The probes were optically characterized. In particular the polarization properties of the optical aperture have been investigated in the far field as well as the near field. Furthermore, preliminary magneto-optical measurements have been performed on a thin garnet film to demonstrate the usefulness of the probes in view of their application in polarization near-field optical microscopy.

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SummaryThe reproducible micromachining of hollow metal tips on Si cantilevers and their applicability to scanning near-field optical microscopy (SNOM) is described. This sensor is fabricated using semiconductor compatible technologies. A hollow metal pyramid is employed as an optical aperture sensor for SNOM and simultaneously as a force sensor for scanning force microscopy applications. Apertures down to 120 nm were realized. To confirm the feasibility of the sensor we present measurements on microstructured chromium films as well as on hot filament chemical vapour deposition grown (111) diamond membranes. The SNOM images show a resolution of about 100 nm, demonstrating the usefulness of these probes.

We report on a silicon‐based microfabrication process to generate apertures with dimensions of less than 100 nm at the apex of hollow silicon dioxide tips. The fabrication process is self‐adjusting and leads to highly reproducible aperture dimensions. It relies substantially on the inhomogeneous thickness distribution and modified etch rate of a silicon dioxide layer thermally grown on structured (001) oriented silicon wafers at relatively low temperatures of about 900–950°C. Process parameters are presented to obtain single or double aperture tips. Once the apertures are fabricated, a further reduction of aperture size below 80 nm is achieved by thin film deposition of, e.g., metal layers or other materials. The possibility of fabricating apertures reliably and reproducibly on large areas, e.g., complete silicon wafers, is emphasized. © 2000 The Electrochemical Society. All rights reserved.