Doped Ge–Sb–Te phase-change materials for reversible phase-change optical recording

Abstract

Differently doped Ge–Sb–Te phase-change recording films were prepared by the individual dc magnetron sputtering of Sn 5Ge 3Sb 72Te 20, In 5Ge 3Sb 72Te 20, Ga 5Ge 3Sb 72Te 20 and Bi 5Ge 3Sb 72Te 20 targets. A close relationship was observed between surface roughness and reflectivity. The Ge–Sb–Te films doped with Bi showed the highest surface roughness and reflectivity. The phase-change optical disks with Bi-doped Ge–Sb–Te recording films showed the best overwriting characteristics. Therefore, the reversible recording properties of the phase-change optical disk were dominated by the composition of the recording film.