The mechanical and protective properties of plasma enhanced chemical vapor
deposition (PECVD) a-C:H films were studied in terms of their use as wear r
esistant and chemically inert coatings for optical and electronic products,
The effect of the discharge power and gas mixture composition on the hardn
ess and wear resistance of a-C:H films, as well as on the level of mechanic
al stresses in the film-substrate system, has been studied. By varying the
synthesis parameters we have succeeded in obtaining films of hardness up to
16 GPa. Diamond-like films are shown to exceed monocrystalline silicon in
wear resistance. Internal stresses in the film-substrate system attain 1 GP
a. The introduction of nitrogen into the methane-hydrogen gas mixture cause
s the strength to increase and internal stresses to halve. Atomic force mic
roscopy (AFM) was used to study variations in the surface morphology of a-C
:H films synthesized under different conditions. The stability of a-C:H fil
m to annealing in the air, light irradiation, chemically active etching sol
utions, and to environmental factors (enhanced humidity, salt fog, temperat
ure, dynamic dust, etc.) was also studied. Diamond-like carbon (DLC) films
have been applied to germanium products as external protective layers of in
frared multilayer antireflection coatings. The use of DLC film as a barrier
coating for the heating layer of inkjet print cartridges has enabled a ten
fold increase in service life. (C) 2000 Elsevier Science S.A. All rights re
served.