Micromachined probe for high density data storage

Near-field aperture probes with high optical transmittance efficiency for optical recording and multi-probes with a metal wire as a heater for thermal recording are batch-fabricated by silicon micromachining. The aperture with diameter sizes from 10 to 500 nm at the apex of a SiO₂ tip on a Si cantilever is fabricated using a "Low temperature Oxidation & Selective Etching" technique. The SiO₂ tip is formed by nonuniform Si wet oxidation at 950°C. The aperture is created at the apex of SiO₂ tip by selective etching SiO₂ in a buffered-HF. The aperture shows a high optical transmittance because the SiO₂ tip has a large opening angle. This fabrication technique is extended to fabricate a metal nanowire at the apex of the SiO₂ tip by embedding a metal into the aperture. By flowing a current into the metal wire, the tip can be heated. This probe array is fabricated, and the basic characteristics are evaluated.