Phase Change Optical Storage - A Critical Assessment

Abstract

-Recently there has been renewed interest in phase transformation based optical storage technology. Included among the many reasons for this interest has been the achievement of: (1) fast erase in conjunction with data stability, (2) demonstration of direct overwrite with good erasability, and in the last couple of years, (3) good progress in increasing the cyclability of the media. Direct overwrite has been demonstrated at media speeds from 1.25 to 22m/s. More than 2x10 6 cycles have been achieved with low BER. In addition, phase change media exhibits strong signal response at wavelengths shorter than 830nm and requires a much simpler optical head. In this paper we review past progress and assess the current status.

The influence of oxygen and nitrogen doping on GeSbTe phase-change optical recording media properties

“…The crystallization temperature on the other side is found empirically to fall in the range of 1/3 and 2/3 the melting temperature [9]. It was furthermore established [10] that materials, which crystallize at more than 423 K (10 K/min heating rate) are preferable to ensure archival stability of the amorphous data. Finally the glass transition temperature T g , which is a measure for the stability of the amorphous state, is typically 50-70% of T x .…”

Optical and electrical properties of amorphous thin films in Gex Te1-x system

“…GeTe-based alloys are used in erasable phase change optical data storage due to their fast crystallization [7][8][9]. The composition dependency of laser-induced crystallization characteristics as well as the annealing effects of GexTe~.~ thin films have been investigated [10].…”