Comment innotec SNF 2006-09-26 10:41:46: Intermittant crystal monitor OK?

[jimkruger at snf.stanford.edu]

Gibby had reported poor behavior of the crystal monitor.
When I replaced the crystal, I noticed flaking from the face of the crystal holder.  With a litle pursuation, everything peeled back to what appeared to be a Cu layer.  I surmise that the flaking was due to the weak oxide formed on Cu when open to the air.  If  the Cu to Oxide interface fails, overlayers will peel.
I suggest that the crystal and holder be replaced after each deposition of materials with mechanically weak oxides like Cu.
jim