MeVSi离子轰击SiO_2溅射行为研究

Study on the sputtering mechanism of SiO_2 irradiated with MeV Si ions

利用飞行时间谱仪 (TOF)技术测量了 1— 5MeVSi离子轰击SiO2 产生的Si+ 二次离子动能分布和溅射产额 .实验发现 ,当入射离子能量在 1— 2MeV时 ,溅射产额随离子能量上升而下降 ,这个趋势利用核溅射理论可以较好地解释 ;当入射离子能量高于 3MeV时 ,溅射产额随离子能量上升而增加 ,电子溅射机理开始占主要地位 ,并且溅射规律与热峰模型的预期符合 .通过对实验结果的综合分析 ,得到了重离子溅射SiO2 的普适溅射产额公式 .

Sputtering yield and kinetic energy distribution (KED) of Si+ from the SiO 2 sample bombarded with 1—5 MeV Si ions were measured with a conventional time of flight (TOF) facility. The results show that the sputtering yield decreases when the ion energy increaseed from 1 to 3MeV, and then it increases quickly if the ion energy is further increaseed. However, the average kinetic energy of the sputtered secondary ions always drops while the incident ion energy is increased. These phenomena can be explained by the mixture of the nuclear sputtering and the electronic sputtering processes. With the experimental data obtained in this study, and the data from other papers, a general function for calculating the total sputtering yield for heavy ions bombarding SiO 2 has been derived.