INFICON XTC/C Thin Film Deposition Controller User Manual
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XTC/C - XTC/2 Operating Manual
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 senor cable,
connector, contact springs,
connecting wire inside sensor,
and feedthroughs
d. check for thermally induced
electrical short or open
condition
d. see "c" above
NOTE: Crystal life is highly dependent on process conditions of rate, power radiated from
source, location, material, and residual gas composition.
3. crystal does not oscillate or
oscillates intermittently (both
in vacuum and in air)
a. intermittent or poor
electrical contact (contacts
oxidized)
a. use an ohm meter or DVM
to check electrical continuity,
clean contacts
b. leaf springs have lost
retentivity (ceramic retainer,
center insulator)
b. rebend leafs to
approximately 60°. See
.
c. RF interference from
sputtering power supply
c. verify earth ground, use
ground strap adequate for RF
ground, change location of
instrument and oscillator
cabling away from RF power
lines, connect instrument to a
different power line
d. cable/oscillator not
connected, or connected to
wrong sensor input
d. verify proper connections,
and inputs relative to
programmed sensor
parameter
4. crystal oscillates in vacuum
but stops oscillation after
open to air
a. crystal was near the end of
its life; opening to air causes
film oxidation which increases
film stress
a. replace crystal
b. excessive moisture
accumulates on the crystal
b. turn off cooling water to
sensor prior to venting, flow
warm water through sensor
while chamber is open
Table 6-2 Troubleshooting Transducers/Sensors (continued)
SYMPTOM
CAUSE
REMEDY