新型相变材料Ti_(0.5)Sb_2Te_3刻蚀工艺及其机理研究

Study on Etching Process and Mechanism of New Phase Change Material Ti_(0.5)Sb_2Te_3

采用CF4和Ar混合气体研究了新型相变材料Ti0.5Sb2Te3(TST)的刻蚀特性,重点优化和研究了刻蚀气体总流速、CF4/Ar的比例、压力和功率等工艺参数对刻蚀形貌的影响。结果表明,当气体总流量为50 sccm、CF4浓度为26%﹑刻蚀功率为400 W和刻蚀压力为13.3 Pa时,刻蚀速度达到126 nm/min,TST薄膜刻蚀图形侧壁平整而且垂直度好(接近90°)﹑刻蚀表面平整(RMS为0.82 nm)以及刻蚀的片内均匀性等都非常好。

The dry etching characteristic of new Ti0.sSbzTe3 （TST） phase change material was investigated by using the CF4 and Ar gas mixture. The research mainly focuses on how to optimize the experimental parameters such as gas flow rate within the chamber, CFa/Ar flow ratio, the chamber background pressure and the incident RF power applied to the lower electrode. The results show that CF4 mainly plays a role of chemical etching and Ar plays a role of physical bombardment. The etching rate of TST films increases with the increasing concentration of CF4 in the gas mixture. The etching chamber pressure has less effect on the TST film etching speed, while the etching power has larger effect. The etch rate is up to 126 nm/min with the smooth etched surface （RMS=0.82 nm） and TST film profile is almost vertical （approaching 90 using optimized etching parameters, including the total flow rate of 50 sccm, CF4 concentration of 26%, power of 400 W and pressure of 13.3 Pa.