15 - 20
IPN 074-505-P1E
IC6 Operating Manual
15.7.2 Troubleshooting Transducers/Sensors
NOTE: Many sensor head problems may be diagnosed with a DVM (Digital Volt
Meter). Disconnect the short oscillator cable from the feedthrough and
measure the resistance from the center pin to ground. If the reading is less
than 1-2 megohms, the source of the leakage should be found and
corrected. Likewise, with the vacuum system open check for center
conductor continuity, a reading of more than 1 ohm from the feedthrough
to the transducer contact indicates a problem. Cleaning contacts or
replacing the in-vacuum cable may be required.
A somewhat more thorough diagnosis may be performed with the optional
Crystal Sensor Emulator, 760-601-G1. See section 15.9 on page 15-33 for
a discussion of its use and diagnostic capabilities.
NOTE: A more detailed troubleshooting guide is shipped with the sensor. Refer to
that manual for more detailed information in some cases
.
Table 15-8 Troubleshooting Transducers/Sensors
SYMPTOM CAUSE REMEDY
1. Large jumps of thickness
reading during deposition
a. Mode hopping due to
defective crystal
a. Replace crystal, use
ModeLock™ measurement
system
b. Stress causes film to peel
from crystal surface
b. Replace crystal or use
high performance
RunSaver™ crystal; consult
factory
c. Particulate or "spatter"
from molten source striking
crystal
c. Thermally condition the
source thoroughly before
deposition, use a shutter to
protect the crystal during
source conditioning
d. Scratches or foreign
particles on the crystal holder
seating surface (improper
crystal seating)
d. Clean and polish the
crystal seating surface on the
crystal holder
e. Small pieces of material
fell on crystal (for crystal
facing up sputtering
situation)
e. Check the crystal surface
and blow it off with clean air
f. Small pieces of magnetic
material being attracted by
the sensor magnet and
contacting the crystal
(sputtering sensor head)
f. Check the sensor cover's
aperture and remove any
foreign material that may be
restricting full crystal
coverage
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