From kavehm at snf.stanford.edu Thu Aug 2 12:56:07 2012 From: kavehm at snf.stanford.edu (kavehm at snf.stanford.edu) Date: Thu, 2 Aug 2012 12:56:07 -0700 Subject: Problem pquest SNF 2012-08-02 12:56:07: DC Bias and backside Message-ID: Ran two sets of etches, first set using durimid recipe went fine. Had problems during second set using gratan1 recipe. Backside He shot up to to 18.1 sccm when etch started and dc bias was about 1/3 of typical value. From jimkruger at snf.stanford.edu Fri Aug 3 16:37:45 2012 From: jimkruger at snf.stanford.edu (jimkruger at snf.stanford.edu) Date: Fri, 3 Aug 2012 16:37:45 -0700 Subject: Problem pquest SNF 2012-08-03 16:37:45: PQuest bias voltage "jumping"; RF effect on He Message-ID: PQuest bias voltage "jumping". It was mostly OK but someties droped to about half the expectted value. This can be a symtom of a lost chip, fallen doen the dark-space shield. Keep an eye on it and report. One other user has verbally reported this recently. The He backside flow is sometime jumping to eratic values once ther RF starts. I believe the pre-RF value is good, so ignore it after RF comes on until Elmer can take a look at the flowmeter shielding/RF grounding.