From the above discussion, it is clear that significant R&D activity is in place both in the United States and Japan to develop alternative storage techniques to address windows of opportunity that may present themselves in the second part of the next decade as shown in Fig. 7.20.
At this point it appears that magnetic perpendicular recording and structured media are well placed to take hard disk drives well into the next decade, satisfying general purpose computing requirements. It is possible that with these technologies 200 GB capacity hard disk drives will be available within the next decade.
In terms of replacing conventional removable optical disk storage for video-type applications, the United States seems to put more emphasis in its R&D effort into SIL lens approaches with Terastor and into true volumetric storage development with holographic storage and two-photon recording technologies. Most Japanese effort in this area seems to be focused on improving conventional optical disk technologies where the Japanese have a strong lead. Both countries are investigating the merits of thermo-mechanical recording on moving polymer disks, perhaps for mastering purposes.
Both countries seem to be pursuing parallel accessing techniques for optical storage, relying on progress made in optoelectronic array devices as well as MEMS actuators.
Fig. 7.20. Possible roadmap for alternative technologies (derived from various data obtained from Terastor Web site, OITDA storage roadmap, private communications with Holoplex researchers and Call/Recall, Inc. internal reports).
Both Japan and the United States are strongly involved in the development of various probe storage techniques. The Japanese effort seems to lead in materials and system development. The United States seems to have a slight lead in terms of development of parallel access probe storage, possibly because of its present lead in MEMS development. Fig. 7.21 shows the possible evolution of storage capacities in several systems. Unlike in the United States, metrology and mastering technology is an area of high investment in Japan with significant ongoing research in large area e-beam, deep UV laser development, and probe mastering.
Fig. 7.21. Potential evolution of capacity vs. transfer rate and comparison with conventional techniques (Call/Recall 1997 storage survey).