Photoinduced Chemical Vapor Deposition of Amorphous Carbon Films from Chloromethane Using a VUV Laser (157 nm)

摘要

Amorphous carbon (a-C) films with low hydrogen content were deposited at low substrate temperatures from a chlorinated hydrocarbon (CH_3Cl) by photoinduced chemical vpaor deposition with a fluorine laser (157 nm). The optical gap, as determined by photothermal deflection spectroscopy (PDS), decreased from 2.3 to 0.1 eV when the substrate temperature was increased from 303 to 643 K. The films were further characterized by FTIR spectroscopy. micro-Raman spectroscopy, surface acoustic wave spectroscopy (SAWS), and atomic force microscopy (AFM). The presence of chlorine residues in the films was examined by energy-dispersive X-ray fluorescence(EDXRF) spectroscopy. The amount of chlorine decreased significantly between 493 and 518 K, causing the carbon network to restructure into a more graphtic form. Deposition at 643 K produced a chlorine-free a-C film on the quartz substrate.