Dry etching of new phase-change material Al _1.3Sb ₃Te in CF ₄/Ar plasma

The dry etching characteristic of Al _1.3Sb ₃Te film was investigated by using a CF ₄/Ar gas mixture. The experimental control parameters were gas flow rate into the chamber, CF ₄/Ar ratio, the O ₂ addition, the chamber background pressure, and the incident RF power applied to the lower electrode. The total flow rate was 50 sccm and the behavior of etch rate of Al _1.3Sb ₃Te thin films was investigated as a function of the CF ₄/Ar ratio, the O ₂ addition, the chamber background pressure, and the incident RF power. Then the parameters were optimized. The fast etch rate was up to 70.8 nm/min and a smooth surface was achieved using optimized etching parameters of CF ₄ concentration of 4%, power of 300 W and pressure of 80 mTorr.