离子束辅助沉积对类金刚石膜结构影响的计算机模拟

采用分子动力学(MD)模拟研究了离子束辅助沉积(1BAD)生长类金刚石(DLC)膜的物理过程.分 别选C₂分子和Ar离子作为沉积源和辅助沉积粒子.改变Ar的入射能量和到达比(A r／C)，研 究了它对DLC膜结构的影响.重点讨论了Ar辅助沉积引起表面原子的瞬间活性变化对薄膜结构 产生的影响.分析表明，由于Ar离子的轰击引起的能量和动量的传递，大大地增强了C原子在 表面的反冲动能及迁移概率，增加了合成薄膜的SP³键含量.研究结果和实验 观察一致，并从合成机理上给出了一些定量解释. 关键词： 类金刚石膜 离子束辅助沉积 分子动力学模拟

Simulations of the structure characteristic of diamond-like carbon films formed by ion-beam-assisted deposition

Molecular dynamics (MD) simulation was used to study the growth process of dia mond_like carbon (DLC) films synthesized via ion_beam_assisted deposition (IBAD ). The C₂ molecules and Ar ions were selected as deposition and assis tance pr ojectiles, respectively. The influence of the impact energy of Ar as well as the assistance/deposition atomic ratio (Ar/C), on the film structure was investiga ted. The transient mobility and the migration of C adatoms caused by Ar impact were studied. Our results indicate that the impact-induced high recoil energy a nd displacement of deposited C atoms play a leading role in the growth of DLC f ilms. This can be attributed to the incident energy and momentum of assistance Ar. Our results agree well with the experimental observation. Furthermore, it e xplains the growth mechanism partly.