高能氮离子轰击对四面体非晶碳膜的表面改性和摩擦系数影响的研究

摘要

利用过滤阴极真空电弧技术制备了sp3键含量不小于80%的四面体非晶碳(ta-C)膜.利用冷阴极潘宁离子源产生不同能量的氮离子对制备的ta-C薄膜进行轰击,通过X射线光电子能谱和原子力显微镜对薄膜表面结构与形貌进行分析研究.研究表明,随着氮离子的轰击能量的增大,薄膜中的CN键结构略有增大,形成了轻N掺杂;同时,在薄膜表层发生了sp3键结构向sp2键结构的转化;薄膜的表面粗糙度在经过氮离子轰击后从0.2 nm减小至0.18 nm,然后随着轰击能量的增大,表面的粗糙度又增大到0.33 nm.氮离子轰击前后的ta-C薄膜的摩擦系数发生显著改变,从轰击前的0.09 nm左右增大至0.16 nm左右,但是轰击后的薄膜的摩擦系数与氮离子轰击能量没有明显的依赖关系.%The ta-C films with more than 80% sp3 fraction were deposited by FCVA technique, and then were bombarded by energetic N ion. The composition and structure of the ta-C films prior to and after the bombardment of energetic N ion is analyzed by x-ray photoelectron spectroscopy. The surface morphology is investigated by Atomic force microscopy . The result shows that the N concentration in the films slightly increase from 10% to 12% when N ion bombardment energy increases from 1000 Ev to 2200 Ev. The bombardment of energetic N ion induces the conversion of sp3 bond to sp2 bond. The CN bonds can be formed in the films after energetic N ion bombardment. Energetic N ion bombardment is implanted superficially. The RMS of the films decreases from 0. 2 to 0. 18 nm after the bombardment, and then increases again to 0. 33 nm with the increment of the N ion energy. The friction test indicates that the minimum of friction coefficient is about 0. 09 nm before ta-C film was bombarded by energetic N ion. The friction coefficient increased to about 0. 16 nm after the bombardment of N ions. But the friction coefficient does not depend on the N ion energy.