INFICON Cool Drawer Single Sensor - Manual (Page 46)

4 - 6
PN
07
4-
60
9-
P1
A
Cool Drawer Single and Dual Sensors Operating Manual
Crystal does not oscillate or
oscillates intermittently (both
in vacuum and in air). Damaged crystal. Replace the crystal.
Existence of electrical short
or poor electrical contacts. Check for electrical continuity
and short in sensor contacts;
check for electrical continuity
in feedthroughs, refer to
section 4.1.1 on page 4-1 .
NOTE: Check the leaf spring contact shape as part of a routine maintenance inspection.
Flattened or deformed leaf spring contacts in the retainer are common causes of
crystal problems. Lift up each retainer contact spring to a height of approximately
3.3 mm (0.13 in.). See
section 4.3.6 on page 4-9 .
Crystal oscillates in vacuum
but stops oscillation after
open to air. Crystal is near the end of its
life; opening to air causes
film oxidation, which
increases film stress. Replace the crystal.
Excessive moisture
accumulation on the crystal. Turn off cooling water to
sensor before opening it to
air; flow hot water through
the sensor when the
chamber is open.
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). Crystal not properly seated. Check and clean the crystal
drawer. See Figure 4-5 on
page 4-12 .
Excessive heat applied to the
crystal. If heat is due to radiation
from the evaporation source,
move sensor farther away
from source and use Low
Thernal Shock crystals for
better thermal stability; if the
source of crystal heating is
due to a secondary electron
beam, change to a sputtering
sensor.
No cooling water. Check cooling water flow
rate.
Heat is from electron flux. Use sputtering head for
non-magnetron sputtering.
Table 4-1 Symptom, Cause, Remedy (continued)
SYMPTOM CAUSE REMEDY