Shutdown pquest SNF 2010-04-15 14:25:46: shutdown-wafer broke during unloading

[eenriquez at snf.stanford.edu]

Cleaned chamber.  Replaced the silicone o-ring with a viton o-ring to prevent the wafer from sticking to the o-ring. Please do not run the electrode temp > 160.  Also, do not run a process without a wafer.