High density optical disc mastering using photobleachable dye

Abstract

To realize the next generation DVD having a 13〜15 Gbyte recording capacity, we studied mastering processes to extend a resolution limit of the Laser Beam Recorder (LBR) and devised a new mastering process. It uses photobleachable dye which is coated over the photoresist layer. Approximately 20% improvement resulted in a line recording density resolution in the case where the photobleachable dye, having large A parameter and small B parameter, is used together with a photoresist, whose sensitivity was adjusted to that of the photobleachable dye. By this process, a glass master was made having a 0.175 μm pit-length and a 0.4μm track-pitch. These figures show that this new technology can be applied to make a 15 Gbyte glass master still leaving some margin.