INFICON XTC/3 Thin Film Deposition Controller Operating Manual - Manual (Page 176)

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XTC/3 Operating Manual
5. thermal instability: large
changes in thickness reading
during source warm-up
(usually causes thickness
reading to decrease) and after
the termination of deposition
(usually causes thickness
reading to increase) a. inadequate cooling
water/cooling water
temperature too high a. check cooling water flow
rate, be certain that cooling
water temperature is less than
30°C; refer to appropriate
sensor manual
b. excessive heat input to the
crystal b. if heat is due to radiation
from the evaporation source,
move sensor further away from
source and use sputtering
crystals for better thermal
stability; install radiation shield
c. crystal not seated properly in
holder c. clean or polish the crystal
seating surface on the crystal
holder
d. crystal heating caused by
high energy electron flux (often
found in RF sputtering) d. use a sputtering
sensor head
e. poor thermal transfer from
water tube to body (CrystalSix
or Crystal12 sensor) e. use a new water tube
whenever the clamping
assembly has been removed
from the body; if a new water
tube is not available, use a
single layer of aluminum foil
between the cooling tube and
sensor body, if your process
allows
f. poor thermal transfer
(Bakeable) f. use Al or Au foil washer
between crystal holder and
sensor body
Table 6-2 Troubleshooting transducers/sensors (continued)
SYMPTOM CAUSE REMEDY