HPQ2-IP SP101009.102 – 10 October 2012
MKS Instruments, Spectra Products
20
4.3 Installing the Analyser
The vacuum chamber in which you intend to mount the analyser must have a 2.75
inch UHV Conflat flange fitted with a tube of 35.0mm (1.378 ") minimum inner
diameter inclusive of a good welded joint.
The distance from the end of the analyser to its mounting flange is 1.0 inches
(25.4mm).
There must be at least the distance given above free of obstructions inside the
vacuum chamber. We recommend you to allow an extra 3mm (0.125 inch) just to
be sure. If your chamber does not have that much room or only a small flange you
should use a specially designed adapter so that the analyser can be mounted
outside the chamber. Please contact your local Spectra facility for assistance.
4.4 Checking the System Pressure
The HPQ2-IP analysers must not be operated at pressures higher than 2 x 10
-2
mBar (1.6 x 10
-2
Torr).
If you intend to monitor a process where the pressure exceeds the above you must
make sure you switch off the filaments. We would recommend using a cold cathode
gauge or capacitance manometer with a set point and relay contacts connected to
the external trip socket on the HPQ2-IP control unit. It is permissible to expose the
analyser to high pressure, even above atmosphere, but the filament must be
switched off.
CAUTION
- A worse problem exists in sputter processes where sputtering is meant
to 'throw' materials around corners. If the quadrupole analyser extends into the
'throw area' of the sputtering deposition, it will rapidly become coated and cease to
function properly. Turning off the power to the Quad during sputtering or etching
will not prevent this contamination. It is most important to ensure that the analyser
is shielded from his type of contamination.
Remember the warranty does not cover cleaning of the analyser.
4.5 Mounting the Analyser
The standard 2 ¾ inch Conflat flange on the analyser can be sealed to the vacuum
chamber with either a copper gasket or a Viton® gasket with a square cross
section. Which one you choose depends on the ultimate pressure you expect in
your system.