Voluteer needed to run AMTEtcher Arc Subpression Tests
mcvittie at snf.stanford.edu
Fri Jun 11 11:55:00 PDT 2004
We are still having lots of so called arcing problems with the
Amtetcher. We have tried lots of things to correct the problem but so
far nothing has worked. I believe it is actually a hollow cathode effect
where we are getting a temporary plasma filament going from the plasma
to the hexode or cathode through small spaces between the plastic
shields covering the hexode. Exactly why these filament are forming so
often now compared to the past, I do not know. Mostly likely some
internal component is failing or has changed. Rather than taking the
whole system apart to find this component, I would like to try a few
more less disruptive tests.
My latest thought is that we may be able to suppress this effect if we
switch the rf power control from constant bias voltage (-530V) to
constant power. The thought here is that when a hollow cathode filament
forms, it probably lowers the bias voltage which causes the delivered
power to increase. In the constant power mode, the power would not
increase and hopefully this would help kill or subpress the filament.
I am looking for a volunteer, who could run some process tests for me to
see if idea will work without affecting the process results.
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 422 bytes
Desc: Card for Jim McVittie
More information about the amtetcher