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What sensors work with SC20Fast?

simon.spicerconsulting • Apr 09, 2015

The SC20Fast is for use with clean room CDSEM tools. It is able to cancel the approximately 9 kHz fields made by overhead wafer transport systems. This post explains the rules for selecting the sensors for use with the SC20Fast.

1. The SC20Fast has two sensor inputs "Sensor1(left)" and "Sensor2(right)"
2. The sensors plugged in to the two inputs must be the same.
3. You must not plug "Sensor SC20/AC" or "Sensor SC20/DCMR" into these inputs.
The system will oscillate. It probably will not break.
4. If you are using one "Sensor SC20Fast/AC" it must be in "Sensor1(left)"
The mixer will be disabled.
5. If you are using two "Sensor SC20Fast/AC" (one in each input) the mixer is enabled.
6. If you need DC cancelling you need a DC combiner. (This is not a mixer)
It has inputs for one "Sensor SC20Fast/AC" and one "Sensor SC20/DCMR".
The Combiner output is plugged into "Sensor1(left)". (The mixer is disabled)
This Combiner contains a 25Hz crossover network.
The SC20Fast uses "Sensor SC20/DCMR" below 25Hz, "Sensor SC20Fast/AC" above 25Hz
7. If you need better AC cancelling at 60Hz you need an AC combiner. (this is not a mixer)
It has inputs for one "Sensor SC20Fast/AC" and one "Sensor SC20/AC".
The Combiner output is plugged into "Sensor1(left)". (The mixer is disabled)
This Combiner contains a 800Hz crossover network.
The SC20Fast uses "Sensor SC20/AC" below 800Hz, "Sensor SC20Fast/AC" above 800Hz
You position "Sensor SC20Fast/AC" in the tool for best 9kHz cancelling
You position "Sensor SC20/AC"in the tool for best 60Hz cancelling

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