Properties Of DLC Films Deposited By Using XeCl Excimer Laser With High Power And High Repetition Frequency

Diamond-like carbon films possess a series of unique virtues close or similar to that of diamonds, such as high hardness, low coefficient of friction, large band gap, excellent field electron emission property, transmittance, high thermal conductivity, chemical inert, et al. Especially for the smoothness and much lower substrate temperatures which allowed DLC films to be deposited on heat sensitive materials, such as optical components, glasses and polymers. Hence, a wide variety of applications have been found for these films, primarily in the microelectronics, optics, acoustics and mechanics industries. The research for the preparation, properties and applications of the DLC films has attracted much attention and has progressed quickly during the past decade. Among all the developed techniques used to grow DLC films, pulsed laser deposition (PLD) offers a quick way to deposit films besides another merit of simple operation to vary deposition parameters. Compare to other PVD techniques, the carbon atoms and clusters in the plume generated by excimer laser ablation are more energetic, so they can condense into a film with increased diamond-like characters. But in general, limited by the laser technique, the power and repetition rate of the excimer lasers used in PLD technique do not exceed a hundred Walt and 50Hz, respectively. In this thesis, lots of DLC films were prepared by using an excimer laser with power and repetition frequency as high as 200～500W, 200～500Hz ,respectively. The effects of some parameters such as the laser power density, the repetition rate, the plasma technique and ambient gases on the structure and character of the DLC films under such extreme power and repetition rate conditions were studied seldom. The results indicated that: ⑴The optical properties of the films (UV transmittance, infrared transmittance, band gap) and the containing of sp3 site in the films were increased with the laser power density when its varied from 108W/cm2 to 1010W/cm2; ⑵Keeping the laser power density at 1010W/cm2 , setting the frequency rate at 200Hz, 300Hz and 500Hz,respectively...