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XTC/3 Operating Manual
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Table 6-2 Troubleshooting transducers/sensors
SYMPTOM
CAUSE
REMEDY
1. large jumps of thickness
reading during deposition
a. mode hopping due to
defective crystal
a. replace crystal
b. stress causes film to peel
from crystal surface
b. replace crystal
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
2. crystal ceases to oscillate
during deposition before it
reaches its "normal" life
a. crystal struck by
particulate or "spatter" from
molten source
a. thermally condition the
source thoroughly before
deposition, use a shutter to
protect the crystal during
source conditioning
b. material on crystal holder
partially masking crystal
cover aperture
b. clean crystal holder
c. existence of electrical
short or open condition
c.using an ohm meter
or DVM, check for electrical
continuity in the sensor
cable, connector, contact
springs, connecting wire
inside sensor, and
feedthroughs
d. check for thermally
induced electrical short or
open condition
d. see C above