Problem tylan1 SNF 2007-10-29 14:09:20: actual thickness significantly off from target

[yenilmez at snf.stanford.edu]

I used wet1000 recipe for 4000A target thickness. The actual 
thickness turned out to be 3400 +/- 50 A. 
I ran three wafers in the middle of the boat. The measured thickness was similar on all wafers.