A novel phase change material, Si<sub>2</sub>Sb<sub>2</sub>Te<sub>3</sub> has been reported to show good phase change abilities. Etching of this material is a critical step in the fabrication of phase change memory devices. In this paper, the characteristics of Si<sub>2</sub>Sb<sub>2</sub>Te<sub>3</sub> etched in CF<sub>4</sub>/Ar atmosphere are investigated. The influence of the etching rate and surface roughness with different CF<sub>4</sub>/Ar ratio, pressure, and power are systematically studied. Furthermore, our X-ray photoelectron spectroscopy test results show that Te is the bottleneck to accelerating the etching rate.