2 monitoring - systems with a source shutter, 3 rate sampling – INFICON XTM/2 Thin Film Deposition Monitor User Manual
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XTM/2 Operating Manual
2.6.2 Monitoring - Systems with a Source Shutter
In addition to measuring rate and thickness, these instruments can be used to
terminate the deposition at the proper thickness. Implementation requires that
the deposition system have a source (or substrate) shutter capable of automatic
operation. The source shutter controller must be wired through the SYSTEM I/O
connector on the rear panel of the instrument. The following parameters (in
addition to those required in
) must also be
programmed.
FINAL THICKNESS . . . . . . . . . . . Program to the desired film thickness (or
mass).
The operator manually increases the source power (using the source power
supply’s control) to the nominal operating level. Once the user is satisfied, the
deposition begins when the OPEN switch is pressed. This action zeros the
accumulated thickness display and opens the source shutter. The operator
must then adjust the source power manually to achieve the desired rate. The
shutter will close automatically when the final thickness set point is achieved.
2.6.3 Rate Sampling
It is possible to use these instruments to periodically sample the rate in a
deposition system. A shuttered transducer must be used, see
NOTE: It will be useful to refer to the separate INFICON Crystal Sensor Manual
(see list below) for transducer and actuator control valve installation.
IPN
Type
074-154 . . . . . . Bakeable
074-155 . . . . . . CrystalSix
074-156 . . . . . . Standard, Compact and Dual
074-157 . . . . . . Sputtering
1
Electrically connect the pneumatic shutter actuator control valve (IPN
007-199) to the sensor shutter pins (1, 2) of the SYSTEM I/O connector.
2
Program the FINAL THICKNESS parameter to a value which allows
approximately 20 seconds of material accumulation onto the sensor head.
For example, if the nominal rate is 20 Å/sec, set the final thickness to 20 sec
x 20 Å/sec = 400Å. If the sample time is too short there could be errors
induced by temperature transients across the monitor crystal.
A sample is initiated by pressing OPEN. This zeros the displayed thickness and
opens the sensor shutter. The operator may view the deposition rate display
(allowing it to stabilize) and then comparing it to the desired rate. If a time longer
than the programmed sample time is required to adjust the actual deposition
rate the operator can increase the FINAL THICKNESS value.
NOTE: This arrangement does not allow automatic substrate final thickness
termination.