Sf. Rusli,"yoon et al., Metal-containing amorphous carbon film development using electron cyclotron resonance CVD, DIAM RELAT, 10(2), 2001, pp. 132-138
A technique for depositing metal-carbon (Me-C:H) thin films is demonstrated
based on two metal screen grids embedded within an electron cyclotron reso
nance chemical vapour deposition (ECR-CVD) system. The grids are negatively
biased and supported at adjustable distances above the substrate holder in
the deposition chamber. With source gases of methane and argon, sputtering
of the metal grids by Ar+ results in the incorporation of metal in the gro
wing carbon films. The amount of metal in the films can be very well contro
lled over a wide range by varying the bias voltage at the grids, the separa
tion of the grids from the substrate holder and the ratio of CH4/Ar. Furthe
rmore, by separately biasing the substrate holder, the properties of the fi
lms can be varied resulting in the formation of a great variety of Me-C:H f
ilms with very different mechanical and structural properties. Tungsten (W-
C:H) and molybdenum (Mo-C:H) incorporated carbon films were deposited using
this technique, with the metal fractions controlled by varying the flow ra
tio of CH4/Ar and the bias at the substrates. The films were characterised
using Rutherford backscattering, X-ray diffraction and Raman scattering mea
surements, and also in terms of their conductivity, optical absorption and
hardness. Large changes are observed in the conductivity and optical gap of
the films even at low fraction of metal incorporated. Metal carbides forma
tion was observed for films deposited under bias. The results suggest that
the substrate bias has a crucial effect on the incorporation of metal into
the a-C:H films and their resulting microstructures. (C) 2001 Elsevier Scie
nce B.V. All rights reserved.