A radio frequency power supply structure and a plasma CVD device
comprising the same are provided in which reflection of radio frequency
power at a connecting portion where an RF cable connects to an electrode
is reduced so that incidence of the radio frequency power into the
electrode increases. In the radio frequency power supply structure for
use in a device generating plasma by charging a plate-like electrode with
a radio frequency power, the radio frequency power supply structure
supplying the electrode with the radio frequency power from an RF cable,
the RF cable is positioned on an extended plane of a plane formed by the
electrode to connect to the electrode at a connecting portion provided on
an end peripheral portion of the electrode. The RF cable connects to the
electrode substantially in the same plane as the plane formed by the
electrode. Voltage acting after the connecting portion becomes symmetric
relative to the plane formed by the electrode and the electric line of
force also becomes symmetric. Thereby, change of impedance at the
connecting portion is reduced, reflection of the radio frequency power at
the connecting portion is reduced, incidence of the radio frequency power
into the electrode increases and the efficiency of film forming and
surface treatment is enhanced.