Problem amtetcher SNF 2010-10-19 19:08:31: asml marks come out shallow

echo user "yeh" on the slow si etch rate and nonuniformity. i ran program #4 for 5 minutes (after 20 minute season) and etched the marks into a layer of polysilicon.
wafer #1: 98-105nm range (n=4 measurements)
wafer #2: 89-92nm range (n=2)
spec etch rate is 240A/min for poly. measured varies from 180-210 A/min with ~5% variation on a single wafer and 10% wafer to wafer.
this agrees with substantial WQ% variation i've been seeing between wafers and for marks on a single wafer (e.g. 40-80% range on a single wafer). something for asml users to be aware of.