INFICON XTM/2 Thin Film Deposition Monitor - Manual (Page 112)

6 - 10
IP
N 07
4-
18
6S
XTM/2 Operating Manual
6. poor thickness
reproducibility a. variable source flux
distribution a. move sensor to a more
central location to reliably
sample evaporant, ensure
constant relative pool height
of melt, avoid tunneling into
the melt
b. sweep, dither, or position
where the electron beam
strikes the melt has been
changed since the last
deposition b. maintain consistent
source distribution by
maintaining consistent
sweep frequencies, sweep
amplitude and electron
beam position settings
c. material does not adhere
to crystal c. make certain the crystal’s
surface is clean; avoid
touching crystal with
fingers, make use of an
intermediate adhesion layer
d. cyclic change in rate d. make certain source’s
sweep frequency is not
"beating" with the
measurement frequency
[nearly the same frequency
or a near multiple of the
measurement (4 Hz)]
7. large drift in thickness
(greater than 200 Å for a
density of 5.00 g/cc) after
termination of sputtering a. crystal heating due to
poor thermal contact a. clean or polish the crystal
seating surface on the
crystal holder
b. external magnetic field
interfering with the sensors
magnetic field (sputtering
sensor) b. rotate sensor magnet to
proper orientation with
external magnetic field,
refer to sputtering sensor
manual IPN 074-157
c. sensor magnet cracked
or demagnetized
(sputtering sensor) c. check sensor magnetic
field strength, the maximum
field at the center of the
aperture should be 700
gauss or greater
Table 6-2 Troubleshooting Transducers/Sensors (continued)
SYMPTOM CAUSE REMEDY