Epitaxial Growth by D.c. Magnetron Sputtering of Carbyne (Chaoite) Microcrystals on CVD-Deposited Polycrystalline Diamond - Polyynes: Synthesis, Properties, and Applications - page 41

deposition time, diamond crystals with a preset size and preferred orienta-
tion of growth, i.e. (111) can be deposited.

3.3.2 D. C .M AGNETRON

An existing D.c. magnetron sputtering system (series 2200, model 2305,
Vacuum Industries Inc.) was completely redesigned to house a tungsten
filament, an optical system for remote temperature measurement, a cassette-
type moveable 6-position sample holder, a set of permanent magnets, an
electron gun sample heating system, a sample temperature control system,
a gas supply and distribution system as well as a pneumatic lift system for
the heavy vacuum chamber top (Figure 3.4).
The magnetron sputtering device uses a magnetic field, created by per-
manent magnets behind the carbon target, that passes through the target
and is traverse to the electric field generated by application of a D.c. poten-
tial to the target. This magnetic field traps electrons formed by ionization of

the residual gas (argon) and emits them from the target surface ( Figure 3.5 ) .

This greatly enhances the deposition rate by intensifying the plasma owing
to the higher density of electrons and the resultant high ionization prob-
ability of the argon gas atoms. When an electron collides with an Ar atom
the latter can be ionized, e Ar þ , and both residual electrons þ Ar ! e þ e þ

FIGURE 3.4 Schematic view of the dedicated D.c. magnetron sputter apparatus.