Hello,
   Plasma needs to be grounded properly otherwise, the flickering
occurs. Now in case of sputtering of polymers, deposition of teflon
etc etc causes the deposition of insulators on the walls and
electrodes of the plasma source. This is one of the main reasons why
the plasma flickers. You may run argon plasma for 1-2 hours to sputter
clean all the surface.
Nabhiraj
Variable Energy Cyclotron Centre
Dept Of Atomic Energy
1/AF, Salt Lake,
Kolkata

On Nov 13, 2007 5:08 AM, PRAMOD GUPTA  wrote:
> Hi
>
>   Does any one know what could be the reasons for Plasma Flickering in Oxford
Plasmalab 80 Plus RIE system?. I am trying to etch polymers with SF6/O2/CHF3 gas
chemistry at 30mTorr, 200W. The recipe was working perfect earlier. Pure O2
plasma, even at 30mTorr, does not flicker at all. It starts flickering when you
mix O2 with SF6 and/or CHF3. What could be the reasons?