InSbTe phase change materials for high performance multi-level recording

The accuracy of achieving each of the specified levels in multi-level optical disk media determines the maximum number of levels that can be used to write data. If the standard deviation of the written reflectivity levels is large, the levels need to be spaced further apart for accurate identification of the levels. If the reflectivity range can be increased, additional levels can be used. This relationship is expressed as a ratio between the standard deviation and the dynamic range (SDR). AgInSbTe materials show the ability to achieve very low SDR at low recording speeds (/spl sim/2-4 m/s) but most often show increasingly higher SDR at higher speeds (>5 m/s). We describe an InSbTe eutectic-based phase change material that can achieve a low SDR at high as well as low speeds (2-6 m/s).