Document No.: 1P0446-1 Rev. B, April 7, 2014
20
NOTE:
The sample holder must make secure contact with both RF and Ground feedthough rails for
proper plasma processing. The IoN 3 MHz should always be operated with the sample holder in place.
The reaction chamber is accessed by opening a hinged door. The chamber door is held in place when
the system is put under vacuum, and a gasket around the rim of the chamber ensures vacuum-tight
sealing between the chamber door and the rest of the chamber. The chamber door hinges are
designed to be loose and slightly offset in order to equalize the inward force on the chamber.
The chamber and chamber door material is extruded, not welded, from 6061-T6 high grade
aerospace aluminum. This ensures good vacuum integrity.
The vacuum system includes a VACUUM PORT (to which the vacuum pump is attached), VENT VALVE
and EXHAUST MANIFOLD. The VENT VALVE
is a “normally open” valve that will allow the chamber to
vent to atmosphere whenever the VACUUM PORT is not activated.
This “normally open” vent valve is
also a safety feature.
When the VACUUM switch is released or turned off (no illumination), the chamber is isolated from the
pump and the VENT VALVE allows air to pass into the vacuum chamber through the VENT VALVE,
venting the system to atmospheric pressure.
The IoN 3 MHz has an electronically controlled gas solenoid valve that will open to allow gas into the
chamber when the RF comes on. If the process is stopped, timed out or aborted, the gas inlet
solenoid valve will close. It is a
“
normally closed
”
valve, and in case of loss of electrical power, it will
close preventing gas from entering the chamber.
5.2
Controls and Indicators
This section describes the controls and indicators on the front and rear of the IoN 3 MHz system.
Figure 5-2
front panel
