Effects of the ion-beam voltage on the properties of the diamond-like carbon thin film prepared by ion-beam sputtering deposition

• Published in: Chinese physics B Vol. 24; no. 6; pp. 581 - 585
• Main Author: 孙鹏 胡明 张锋 季一勤 刘华松 刘丹丹 冷健
• Format: Journal Article
• Language: English
• Published: 01.06.2015
• Subjects: Bonding; Carbon; Diamond-like carbon films; DLC膜; DLC薄膜; Electric potential; Infrared; Ion beams; Thin films; Voltage; 性能; 电压; 离子束溅射沉积; 类金刚石碳薄膜; 红外光学特性; 靶制备
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/24/6/067803

Diamond-like carbon （DLC） thin film is one of the most widely used optical thin films. The fraction of chemical bondings has a great influence on the properties of the DLC film. In this work, DLC thin films are prepared by ion-beam sputtering deposition in Ar and CH4 mixtures with graphite as the target. The influences of the ion-beam voltage on the surface morphology, chemical structure, mechanical and infrared optical properties of the DLC films are investigated by atomic force microscopy （AFM）, Raman spectroscopy, nanoindentation, and Fourier transform infrared （FTIR） spec- troscopy, respectively. The results show that the surface of the film is uniform and smooth. The film contains sp2 and sp3 hybridized carbon bondings. The film prepared by lower ion beam voltage has a higher sp3 bonding content. It is found that the hardness of DLC films increases with reducing ion-beam voltage, which can be attributed to an increase in the fraction of sp3 carbon bondings in the DLC film. The optical constants can be obtained by the whole infrared optical spectrum fitting with the transmittance spectrum. The refractive index increases with the decrease of the ion-beam voltage, while the extinction coefficient decreases.