The effect of thickness on the Bi–Ge–Sb–Te films for reversible phase-change optical recording

The Bi–Ge–Sb–Te phase-change recording films were prepared by the dc magnetron sputtering of a Bi5Ge9Sb68Te18 target in an atmosphere of Ar. The surface of the Bi–Ge–Sb–Te films grew in the form of needles as the film thickness increased. There was the close relation among the film thickness, surface roughness, and optical properties. The Bi–Ge–Sb–Te film with a thickness of 16 nm had the lowest jitter value and the highest modulation value. As the results, the film thickness affected the Bi–Ge–Sb–Te film for phase-change optical recording significantly.