Effects of nitrogen content and nitrogen plasma post-treatment on diamond-like carbon films

• Main Authors: Yan-Li Fang, 方彥理
• Other Authors: Shinn-Shyong Tzeng
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/35028240452638635714

碩士 === 大同大學 === 材料工程學系(所) === 97 === 英文摘要 Diamond-like carbon (DLC) films were deposited on silicon substrate using acetylene as carbon source by RF plasma enhanced chemical vapor deposition (RF-PECVD). The deposition at different acetylene/nitrogen ratios, different plasma post-treatment atmosphere and times, and nitrogen plasma post-treatment at different pressures were investigated. The surface roughness, microstructure and film thickness of DLC films were characterized by Atomic Force Microscopic (AFM), Raman Spectroscopy and Alpha-Step profilometer. The surface hardness,Young’s Modulus and residual stress were analyzed by nano-indenter and Michelson interferometer, respectively. The experimental results shows that the surface roughness of DLC film decreased slightly with increasing acetylene/nitrogen ratio. The Raman results indicate that sp2 proportion in DLC films increased when the acetylene/nitrogen ratio decreased. Also, the deposition rate showed a rapid reduction. For the hydrogen plasma post-treatment, the surface roughness decreased when raising the treatment time. On the other hand, it increased dramatically after nitrogen plasma post-treatment was performed. For the measurement of film thickness, it was found that the film thickness decreased after both nitrogen and hydrogen plasma post-treatments were performed. Nitrogen post-treatment at different pressures show that , post treatment at a higher pressure 0.9torr resulted in a rougher surface, and the hardness reduce a little. On the other hand, post-treatment at a lower pressure 0.15 torr, led to a smoother surface with a larger decrease in hardness.