Surface Morphology Of Carbon Films Research Articles

Photo-induced Electron Emission of Nanostructured Carbon Thin Film Based Transmission Photocathodes at Different Electric Field

Very thin nanostructured carbon films were deposited on quartz substrate by reactive magnetron sputtering using graphite target and gas mixture of Ar and reactive gas N_2 or N_2+H_2. Film thicknesses were in the range of 20-25 nm. Rutherford backscattering spectrometry and Elastic recoil detection analytical method determined the concentration of elements in the films. Scanning electron microscopy scanned the surface morphology of carbon films. Raman spectroscopy was used for chemical structural properties determination of very thin carbon films. Raman spectra intensities were fitted with Gaussian peaks. The photo-induced (pulsed laser - 266 nm) electron emission properties of very thin nanostructured carbon films were investigated by the measurement of cathode bunch charge at different electric field and calculate quantum efficiency. The influence of different electric field on the photo-induced electron emission characteristics of prepared transmission photocathodes are discussed.

Chemical and physical sputtering effects on the surface morphology of carbon films grown by plasma chemical vapor deposition

We have studied the influence of chemical and physical sputtering on the surface morphology of hydrogenated carbon films deposited on silicon substrates by bias-enhanced electron cyclotron resonance chemical vapor deposition. Atomic force microscopy based power spectrum density (PSD) and roughness analysis have been used to investigate the film morphology. This study has been possible due to the appropriate choice of the experimental variables, in particular, gas mixture, resulting in either nitrogen-free (a-C:H) or nitrogenated carbon (a-CN:H) films, and substrate bias (Vb). Under these conditions, chemical sputtering is present for a-CN:H deposition but it is negligible for a-C:H film growth, while physical sputtering processes appear for both systems for Vb≤−85 V. When physical sputtering does not operate, the film growth with simultaneous chemical sputtering leads to a characteristic a-CN:H granular surface morphology. Furthermore, PSD analysis reveals that a spatial correlation of the a-CN:H film surface roughness, up to distances ∼300 nm, becomes a fingerprint of the coexistence of growth and chemical erosion processes on the film morphology. However, once physical sputtering takes place, the influence of chemical sputtering by reactive nitrogen species on the final surface morphology becomes negligible and both a-CN:H and a-C:H film morphologies are ultrasmooth.

Properties of Carbon for Application of New Light Source Technology

Carbon films was grown on Si substrates using the method of electrolysis for methanol liquid. Deposition parameters for the growth of the carbon films were current density for the electrolysis, methanol liquid temperature and electrode spacing between anode and cathode. We examined electrical resistance and the surface morphology of carbon films formed under various conditions specified by deposition parameters. It was clarified that the high electrical resistance carbon films with smooth surface morphology are grown when a distance between the electrodes was relatively wider. We found that the electrical resistance in the films was independent of both current density and methanol liquid temperature for electrolysis. The temperature dependence of the electrical resistance in the low resistance carbon films was different from one obtained in graphite.

Influence of ion energies on the surface morphology of carbon films

Diamond-like carbon (DLC) films were deposited using vacuum arc deposition (VAD) and plasma immersion ion implantation and deposition (PIII and D). The surface morphologies of these films were investigated using atom force microscopy (AFM). Raman spectroscopy results show that the films have different microstructures. Based on the AFM images and Raman spectra, the aromatic ring cluster diameters hardly affect the surface morphology of the films, but the surface growth and nucleation are all subjected to the ion energies and the substrate temperature determines the surface morphology of the films.

Effect of technological parameters on the structure and surface morphology of carbon films

Technological parameters and conditions providing control over the process of surface morphology formation in the films of the various allotropic carbon phases are established. Using these conditions, it is possible to obtain carbon films with preset properties, in particular, the values of surface density and the size of diamond-like or graphite nano-and microcrystallite.