INFICON IQM-233 Thin Film Deposition Controller PCI-Express Card Operating Manual - Manual (Page 83)

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IQM-233 Operating Manual
Thickness reproducibility
is poor. Erratic evaporation flux
characteristics. Move sensor to a different
location.
Check the evaporation
source for proper operating
conditions.
Ensure relatively constant
pool height and avoid
tunneling into the melt.
Assign multiple sensors to
the source.
Material does not adhere well
to the crystal. Check for contamination on
the crystal’s surface.
Evaporate an intermediate
layer of appropriate material
onto the crystal to improve
adhesion.
Use gold, silver, or alloy
crystals, as appropriate.
Rate control is poor. PID control loop parameters
are incorrect. Test in Manual mode to
ensure a stable rate is
possible.
Change PID control loop
parameters. Refer to
section
6.5.2, Loop Tuning
Procedure, on page 6-7
.
Electron beam sweep
frequency “beating” with the
IQM-233 card's
measurement frequency. Adjust the sweep frequency
so it is not in phase with the
IQM-233 card's
measurement frequency.
Resolution is too low. Increase the measurement
period.
Use measurement
averaging.
Table 5-1 Symptom/Cause/Remedy Chart (continued)
SYMPTOM CAUSE REMEDY