Metal-containing (Co, Al and Ti) amorphous carbon composite films (a-C:Me)
have been prepared by the filtered cathodic are technique using metal-conta
ining graphite targets at room temperature. Field emission properties of th
e heat-treated a-C:Me films were improved and were found to be dependent on
the metal content and variety of metals. After heat-treatment at 550 degre
esC in a mixture of acetylene and nitrogen gases, the field emission proper
ties of a-C:Co films were significantly improved, in which Co acted as cata
lysts to enhance graphitization as well as formation of carbon nanotubes du
ring heat-treatment. A threshold electric field of less than 2 V/mum was ob
tained from the heat-treated a-C:Co composite films without conditioning. T
he heat-treated a-C:Al and a-C:Ti films, though the conditioning step could
be avoided and relatively low threshold fields could be obtained, exhibite
d relatively low emission site densities, however. The a-C:Me films, which
can be deposited with a high rate at room temperature and require a relativ
ely low temperature, heat-treatment process to enhance electron emission, a
re promising for practical applications in field emission display. (C) 2001
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