Ge/sub 2/Sb/sub 2/Te/sub 5/ thin film doped with silver [optical disc storage]

The reflectivity and thermal properties are the main problems in GeSbTe phase-change disks that must be improved (N. Nobukuni et al., J. Appl. Phys. vol. 78, p. 6980, 1995; A. Hirotsune et al., Jpn. J. Appl. Phys. vol. 35, p. 346, 1996; C.M. Lee et al., J. Appl. Phys. vol. 89, p. 3290, 2001; S.Y. Kim et al., Jpn. J. Appl. Phys. vol. 38, p. 1713, 1997). We found that a small amount of Ag addition to the Ge/sub 2/Sb/sub 2/Te/sub 5/ film can increase the reflectivity, crystalline temperature, and the fcc to hcp phase-transition temperature. In addition, the activity energy of the amorphous to fcc phase transition was decreased.