| The objective of this dissertation research was to create a high-density optical memory device. From an engineering point of view, to create a promising durable optical memory device with high density requires a simple, efficient, effective storage method. This need led to the concept of creating a three-dimensional memory by storage of many bits data in a single physical location. Unlike conventional multi-layer 3D structure, this was accomplished in a single layer structure using a dielectric thin film. The resulting digital thin-film (DTF) structure was investigated in order to prove and demonstrate that the vertical interference properties of micro-scale Fabry-Perot filters array can be used as the basis for optical data storage cells.; Optical memory devices are conventionally fabricated by laser beam processing. In this work, a Ga+ focused ion beam was used to “write” data on a SiO2 film grown on Si as proof of concept and demonstration of this DTF structure. The use of FIB milling has the advantage of creating smaller data storage elements and higher data density since the ion beam can be focused into a much smaller spot size than that of lasers. The FIB-written data creates a sub-micron structure with multiple bit capacity per physical location and can be read by far-field optical detection methods. A bit density of 5 Gbit/in2 which is roughly double the current storage density of a DVD has been obtained. The extended lifetime of data stored on a robust material such as SiO2/Si produces a data storage option with excellent survival under harsh environment such as high temperature, radiation, etc. |
