离子轰击对金刚石核形成能影响的理论探讨

Theoretical Approach of Influence of Ion Bombardment on Forming Energy of Diamond Nucleus

金刚石核化是制备金刚石薄膜的关键。目前 ,负偏压是增强金刚石核化最有效的方法。本工作着重计算了在负偏压增强金刚石核化的过程中 ,金刚石在离子对衬底表面进行轰击导致衬底表面产生微缺陷 (凹坑 )上成核的形成能 ,给出了金刚石的核化能 ,核化密度以及核化速率与凹坑密度的解析函数。结果表明金刚石的核化能随凹坑密度的增大而降低 ,从而导致核化密度及核化速率的提高 ,与文献中的实验结果相一致。分析和讨论了凹坑降低金刚石核形成能的原因。

Diamond nucleation is the key of synthesizing diamond films. At present, the negative bias is the most effective method of enhancing diamond nucleation. In this work, the forming energy is emphatically calculated that a diamond nucleus is built up on a micro defect (pit) produced on the substrate surface by ion bombardment in the process of negative bias enhanced diamond nucleation. The analytic function between nucleation energy of diamond, nucleation density, nucleation speed and pit density is given in some reasonable formulas. The results indicate that descent of the nucleation energy of diamond with the pit density resulted in enhancement of nucleation density and nucleation speed, and the results are in agreement with experimental results in conferences. The reason of the pit reduced the nucleation energy is analyzed.