Nanowear of GeSbTe thin film under atmospheric environment

Abstract Nanowear behaviors of GeSbTe against SiO2 microsphere were investigated by using an atomic force microscope under atmospheric environment. During the wear tests, the normal load and wear time was set as 5–10 μN and 1–50 s, respectively. The experimental results showed that the normal load and wear time played an important role in the nanowear of GeSbTe. With the increase of the normal load and wear time, the depth of wear scar formed on GeSbTe surface would increase. According to the nanowear tests in pure nitrogen, it was suggested that the nanowear of GeSbTe under atmospheric environment with different loading conditions was dominated by mechanical interactions. Further calculations indicated that the nanowear of GeSbTe under atmospheric environment was caused by the strong shear stress. Meanwhile, the nanowear of GeSbTe would also be affected by the dissipated energy generated in the friction process. Using one single SiO2 tip with different cleanness, it was verified that the wear debris generated during the wear process acted as a lubricant. Consequently, the nanowear of GeSbTe under atmospheric environment was restrained by the wear debris. The results of this study may help us understand the polishing mechanism of GeSbTe during CMP process.