INFICON STM-2XM 2-Channel Rate/Thickness Monitor - Manual (Page 34)

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STM-2XM Operating Manual
Substrate shutter (optional)
The substrate shutter blocks the evaporant stream from reaching the substrate. A
closed substrate shutter will not allow material to reach the substrate but will allow
evaporant to reach the sensor(s). With a substrate shutter installed, it is possible
to have a shutter delay, where the rate can be pre-established before exposing the
substrate to the evaporant stream. STM-2XM automatically accounts for a
substrate shutter (if programmed) and will not display thickness accumulation while
the substrate shutter is closed. The displayed rate is always "live" even if the
substrate shutter is closed.
NOTE: If STM-2XM is programmed to use a substrate shutter, it ignores changes
in substrate thickness when the substrate shutter is closed. Therefore,
program STM-2XM for a substrate shutter only if a substrate shutter
actually exists in the system.
Sensor shutter (optional)
The sensor shutter blocks the evaporant stream from the sensor. Shuttered
sensors are required for rate sampling, where the sensor monitors the source for a
portion of the deposition. Shuttered sensors are also used in multiple-sensor,
multi-layer systems to keep the sensor from being contaminated with incompatible
materials on different layers
In-Vacuum Cable
The in-vacuum cable connects the sensor to the feedthrough.
Feedthrough
A feedthrough provides isolation between vacuum and atmosphere for electrical
and cooling lines.
15.2 cm (6 in.) BNC Cable
A BNC cable provides a flexible connection from the feedthrough to the oscillator.
Oscillator
The oscillator contains the electronics to operate the quartz crystal. The length from
the oscillator to the crystal should be under 1 m (40 in.).
BNC Cable
A BNC cable connects the oscillator to STM-2XM.
Ground Wire
The ground wire is preferably a solid copper ground strap that connects the
earth-grounded vacuum system to the STM-2XM ground terminal (refer to
section
2.1.2, Ground Requirements, on page 2-2 ).