title: Reactive ion etching of Si(x)Sb2Te in CF4/Ar plasma for nonvolatile phase-change memory device.
abstract: Si(x)Sb2Te material system is novel for phase-change random access memory applications. Its properties are more outstanding than the widely used material Ge2Sb2Te5. Etching process is one of the critical steps in the device fabrication. The etching characteristics of phase-change material Si(x)Sb2Te were studied with CF4/Ar gas mixture by a reactive ion etching system. The changes of etching rate, etching profile and surface root-mean-square roughness resulted from variation of the gas-mixing ratio were investigated under constant pressure (50 mTorr) and applying power (200 W). Si0.34Sb2Te is with the highest phase-change speed and the lowest power consumption in the PCRAM memory among these compositions, which means it is the most promising candidate for the PCRAM applications. So the most optimized CF4/Ar gas ratio for Si0.34Sb2Te was studied, the value is 25/25. The etching rate is 155 nm/min, and the selectivity of Si0.34Sb2Te to SiO2 is as high as 3.4 times. Furthermore, the smooth surface was achieved with this optimized gas ratio.
authors: State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors: Yifeng
authors: Y
authors: Gu
authors: Sannian
authors: S
authors: Song
authors: Zhitang
authors: Z
authors: Song
authors: Yan
authors: Y
authors: Cheng
authors: Xuyan
authors: X
authors: Liu
authors: Xiaofeng
authors: X
authors: Du
authors: Bo
authors: B
authors: Liu
authors: Songlin
authors: S
authors: Feng