Fabrication of Micro-Pyramidal Probe Array with Aperture for Near-Field Optical Memory Applications

A new optical memory system is urgently required to realize high memory capacity and fast data transfer rates in the coming multimedia era. To overcome the current capacity barrier of far-field techniques, a novel near-field optical memory of evanescent wave has been proposed using a vertical cavity surface emitting laser (VCSEL) probe array, consisting of the VCSEL array as a light source and the micro-pyramidal probe array as an evanescent wave exit. The design and fabrication for the aperture probe array were developed in this research. An array of up to 10,000 pieces was prepared successfully using microfabrication processes, including photolithography, silicon wet etching, thermal oxidation and thin film deposition. The pyramidal probes in the array show little variation in size and are sufficiently sharp to apply to the near-field recording head. The probe tip has a small size of 100 nm and the aperture has a diameter of around 150 nm. A smaller aperture can be fabricated with more careful control of the experimental procedures, including the etching process and thermal wet oxidation.