Preparation And Structure Of Nitrogen-doped Dlc Films With Optical And Electrical Properties

In this paper, hydrogen-free diamond-like films and nitrogen doped diamond-like carbon films were prepared on glass substrates by direct current magnetron sputtering with Ar,N₂ as work gas and graphite as target. Atomic force microscope (AFM), X-ray diffraction (XRD), Raman spectroscopy (Raman), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to Characterize and analyze the surfaces and structures of the films. The transmittances, absorption coefficients and optical band-gaps of nitrogen-doped films were studied by a UV - visible spectrometer (UV-VIS) ; the insulation resistance tester and an analysis of bridge-resistant nitrogen-doped were used to study the insulation resistance and dielectric constant influence which caused by introducing nitrogen into the DLC.The results show that diamond-like carbon films and nitrogen-doped diamond-like carbon films can be successfully deposited on glass substrates by DC magnetron sputtering with graphite as target, Ar and N₂ as work gas. diamond-like carbon film and nitrogen-doped diamond-like carbon films. With incorporation of nitrogen in the films, CN, C = N and C≡N bonds were formed , and nitrogen exists mainly in the form of C = N bond . With the nitrogen flux ratio increased, the nitrogen content in the film ascend too, but the proportion of sp³/sp² first increasing and then decreased; increasing nitrogen flux ratio made optical band gap become larger and then decreases, while insulation resistance first increased and then decreased as well as the dielectric constant has been increasing all the time.influences led by process parameters, such as different sputtering powers and substrate temperatures on the films surface morphology, deposition rate, Raman spectroscopy, optical band gap, insulation resistance and dielectric constant were discussed. With other process parameters unchanged, to improve the sputtering power only makes the surfaces of films worse; deposition rate as well as film insulation resistance and optical band gap shows the trend of first increase and then decrease; Keeping Other parameters immovable, the surfaces of films become more uniform and dense after increasing the sputtering substrate temperature; meanwhile, G peak of Raman spectra of films deposited at higher substrate temperature moves to high frequency, indicating more content of sp² in the films; In addition, high substrate temperature makes absorption coefficient of films increase, optical band gap become smaller and the dielectric constant enhanced. The reason is that more carbon atoms and nitrogen atoms were deposited on the substrate in the form of to C-C, C-N bond binding when deposited at a higher substrate temperature, therefore there are more sp² in the films relatively.