Case Number 100064 - Dielectric Thin-Film Color Optical Memory Device and Fabrication Process
Contact: Doug Nienaber
Description: The next generation of optical memory technology will be required to provide significant advances in capacity, data density, and data security. Current technology such as multi-layer CD-ROM structures have disadvantages: due to the higher numerical aperture, smaller laser spot size, and associated smaller depth-of-focus, overall capacity is limited. Similarly, structures comprised of metal thin films are limited by the strong optically reflective characteristics of the films and the difficulty of controlling metal thin-film deposition. Devices using color as memory, while known in the art, are limited by aging of the memory colorant, by the small practical number of colorants usable, and by difficulties in fabrication.
We have developed a dielectric thin-film (DTF) color optical memory device that overcomes these limitations. The invention introduces a new structure for optical memory devices utilizing reflection of a broad-band light source from the DTF structure and a process for creating such structure.
We have invented a technique for ?writing? the data with great precision using micromachining of fine structures with a focused ion beam (FIB) technique. FIB micromachining for the fabrication of optical/photonic devices is an area of expertise at the UC Nanoelectronics Laboratory (NanoLab). For related technology see UC Item # 102-004 and the NanoLab
- The invention promises the creation of structures with a storage density in excess of 5 gigabytes per square inch, more than double the density of present digital versatile disc (DVD) devices. With the addition of near-field detection technology, the invention provides a potential data density of 5 terabytes per square inch.
- The DTF optical memory devices of this invention are generally capable of operation in extreme environmental conditions, including temperatures as high as 1000 degrees C.
- In combination with non-contact optical read techniques, the DTF memory ensures that the data can be preserved over an extremely long time ? perhaps up to centuries.
- The FIB fabrication technique is simple and clean, without the problem of photoresist residues experienced in memory structures utilizing multiple metal film stacks fabricated using deposition and lift-off processes.
Issued US patent # 7,087,281, entitled "Dielectric thin-film color optical memory device and fabrication process"