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Tergeo plasma cleaner operator’s manual
Revision: B3, Year 2020
10.5 Recipe execution stuck in the pumping down state.
Check the “Upper limit pressure before cleaning starts” in the settings screen. If the background
pressure in the sample chamber fails to be pumped to below the set value, the recipe will not start.
Please wipe clean the front surface of the door o-ring. Dust particles on the O-ring can increase the gas
leak rate. This is a very common issue. Please refer to section 10.1
10.6 Gas flow rate can’t reaching the set value
If the gas input port is at atmospheric pressure, the maximum gas flow rate that can be achieved is
around 40 sccm for air. If a higher gas flow rate is required, input gas pressure should be raised to 10 psi
above the atmospheric pressure. Please do not raise the input gas pressure above 15 psi.
10.7 Flow controller oscillate at the set point.
Sometimes when the gas input pressure varies a lot, the noise on the flow meter may temporarily
increase. When this issue happens,
1.
Reduce the inlet pressure to 7 psi. Keep the inlet gas pressure stable.
2.
Power off the system. Wait for 10 minute. Power up the system again.
3.
Set MFC server speed to 5 or less in system screen.
10.8 How to check the leak rate on the gas delivery system
Step 1: Set gas flow rate to zero on all input ports. Pump down the system for more than 15 minutes.
Write down the ultimate pressure.
Step 2: Use ¼” Swagelok caps to close the gas input ports on the back of the enclosure. Set the gas flow
rate to 90sccm and let system pump down the internal gas lines for half an hour. Write down the
ultimate pressure again. If the ultimate pressure is more than 10 mTorr higher than the ultimate
pressure obtained in step 1, it may indicate a leak in the internal gas delivery system. The increase of the
ultimate pressure may vary greatly depending on the pumping speed. For a pump with slow pumping
speed or high ultimate pressure, this value could be significantly higher than 10mTorr.
Step 3: Connect the external gas delivery line, close gas bottle valve. Let it pump down the external gas
lines. If the ultimate pressure is more than 20mTorr higher than the ultimate pressure obtained in step 1,
it may indicate a leak in the external gas delivery system.
Once the internal gas lines are evacuated to vacuum condition, MFCs may show a flow rate below or
above zero. This is normal because the flow sensor zero point may drift under vacuum conditions.
