Bl. Druz et al., FIELD ELECTRON-EMISSION FROM DIAMOND-LIKE CARBON-FILMS DEPOSITED USING RF INDUCTIVELY-COUPLED CH4-PLASMA SOURCE, DIAMOND AND RELATED MATERIALS, 7(2-5), 1998, pp. 695-698
Diamond-like carbon (DLC) films 4-400 nm thick were deposited on condu
ctive n-Si and metal substrates using direct ion beam deposition from
an RF inductively coupled CH4-plasma (ICP) source. The held electron e
mission of the films was examined as a function of deposition conditio
ns and post-deposition surface modification by Ni ultrathin coatings.
Electrical properties of the films were studied as well. A specially d
esigned high vacuum scanning tunnelling-field emission microscope was
employed for simultaneous mapping of the topography, work function and
local held electron emission intensity. Stable, low voltage emission
was observed after the emission electric field/current activation proc
ess. The activation mechanism was probably the formation of conductive
channels in the films to supply electrons for emission from low work
function surface areas. Deposition of ultrathin metal coatings on the
DLC films reduced both the effective barrier height and the held emiss
ion threshold. The DLC films surface coated with ultrathin Ni films re
sulted in electron emission at fields as low as 20-25 V mu m(-1). It w
as shown that DLC films with thicknesses in the range 5-15 nm demonstr
ated efficient field emission long-term stability. The results are int
erpreted based on the reduced electrical resistivity of nanometer scal
e thick films, and deviation of resistivity over the surface. (C) 1998
Published by Elsevier Science S.A.