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Tergeo plasma cleaner operator’s manual
Revision: B3, Year 2020
8.4 Manual operation
In the middle panel, the user can manually pump down and vent the sample chamber, set gas flow rate,
set up rf power supply, switch between immersion and remote processing modes and set the timer.
8.4.1 Pumping down the chamber.
Once the vacuum pump has been manually turned on by the user, the user can then click the “Pump
Down” in the right panel to open the valve between the plasma sample chamber and the vacuum pump.
Sample chamber will then be pumped down.
8.4.2 Set the gas flow rate
Once the background pressure stabilizes during pumping down, the user can set gas flow rate to provide
40~300mTorr pressure in the sample chamber. If the pumping speed is too low, the user may need to
increase the operation pressure further. The labels (white boxes below the Vent, 1, 2, 3 channel names)
for each gas input channels can be updated to corresponding gas species.
8.4.3 Set up the timer
Click the timer button will enable or disable the timer. The box on the left indicates the number of
minutes. The box on the right indicates the number of seconds.
The timer can be triggered by either “plasma on” event or “rf on” event. The trigger option for the timer
can be changed in the system screen. It is suggested to use “plasma on” event as the timer trigger. If the
plasma is too weak to be detected by the plasma sensor, the user can then use “rf on” event as the
timer trigger.
8.4.4 Change the cleaning mode
Default cleaning mode is the direct/immersion cleaning mode. RF power supply will be connected to the
plasma source for the sample chamber in this mode. If the downstream cleaning mode option is
purchased, rf power can be switched to the remote plasma source by clicking the button to the right of
the “cleaning mode” label.
8.4.5 Set up the rf power supply
The user can start rf power supply by typing a value between 1~75watt (for 75watt rf power supply) or
1~150 watt (for 150watt rf power supply) in the top box in the RF power supply subpanel. Duty ratio of
the rf power supply can be adjusted between 0~255 if the pulsing mode option is purchased. For
continuous rf output, the duty ratio should be set to 255. The percentage of the duty ratio can be
calculated as N/255, here N is the value specified in the box. If user set 0 in the pulse ratio box, there will
be no rf power output. Default rf output mode is CW mode, e.g. N=255. The pulsed mode (N<255 ) may
fail to ignite the plasma if the pressure is far above 300mTorr or rf power is too low. For local plasma
source, it is usually easier to ignite plasma when chamber pressure is lower than 50mTorr. For remote
plasma source, the optimal pressure to ignite plasma is about 100mTorr.
