Prospects of Doped Sb–Te Phase-Change Materials for High-Speed Recording

Recording parameters such as crystallization rate, archival life stability and media noise have been studied for phase-change optical discs based on doped Sb–Te materials. It has been found that the crystallization rate can be tuned easily by varying the Sb/Te ratio or the dopant atom; higher crystallization rates are obtained for higher Sb/Te ratios and for In- and Ga-doped Sb–Te. However, it has been found that measures that enhance the crystallization rate often also influence other material properties, such as archival life stability and media noise. For example, a higher Sb/Te ratio leads to a lower archival life and higher media noise. As a consequence, the demands on doped Sb–Te materials to combine sufficiently high crystallization rate, good archival life stability and low media noise become increasingly difficult to satisfy for high recording speeds.