In this article, we report results of an extensive characterization study involving scanning electron microscopy, spectroscopic ellipsometry (SE), photothermal deflection spectroscopy (PDS), x-ray photoelectron spectroscopy, x-ray Auger electron spectroscopy (XAES), current-voltage (I-V) measurements, hydrogen content evaluated from Fourier transform infrared spectroscopy and elastic recoil detection analysis, and also measurement of stress and hardness of diamond-like carbon (DLC) films. These films were grown using methane (CH4), acetylene (C2H2) gases, and benzene (C6H6) vapors into a saddle-field fast-atom-beam (FAB) source. DLC films formed by the saddle-field FAB source technique exhibit extremely low residual stress (0.12-0.26 GPa) and high Knoop hardness (9-22 GPa) measured at 50 g load. The values of optical constants (n, k, epsilon(1), epsilon(2)) evaluated from SE, characteristic energy of band tail (Urbach energy, E-0) evaluated from PDS studies, sp(2) percentage evaluated from XAES data, the density of states [N(E-F)] derived from space-charge-limited conduction, and the hydrogen content are found to decrease, and the sp(3)/sp(2) ratio evaluated are found to increase with the increase of carbon-to-hydrogen ratio in the hydrocarbon gases/vapors used for growing DLC films by this technique. The values of E-0, N(E-F), hydrogen content, and sp(3)/sp(2) ratio of these DLC films are found to be in the range of 180-280 meV, 1-6 X 10(17) eV(-1) cm(-3), 3-8 at. % and 5.2-12.3, respectively, which are lower than the values of E-0 (300-500 meV), N(E-F) (similar to 10(18) eV(-1) cm(-3)), and hydrogen content (15-40 at. %) and higher than sp(3)/sp(2) ratio (1.3-2.5) of DLC films grown by the more conventional rf self-bias technique reported in the literature.