Description
5
GA 05.141/6.02 - 07/2003
1.2 Compatibility with
pumped media
The MAG are specifically designed for the needs of the
semiconductor industry.
All materials used inside the pump are compatible with
typical gases used for semiconductor processes.
Caution
Please consult Leybold for recommendati-
ons on pump models for specific processes
and application requirements.
Corrosion protection
To protect the pump from corrosive gases it is mandatory
to use dry Nitrogen purge during operation of the
pump.The purge gas protects the bearing section and
the motor from corrosive gases.
The rotor and the stator of the pump are KEPLA
®
-coated
to prevent corrosive attack caused by the process
gases. The corrosion protection of the pump is effective
only when the pump is protected from moisture during
standstill and storage. If the process gas contains moi-
sture, contact Leybold for recommendations.
Sublimation
Some media (e.g. AlCl
3
) can sublimate in the pump and
form deposits. Thick coatings can infringe on the requi-
red operating clearence and ultimately cause the pump
to seize. These deposits can also react with moisture
and generate corrosive gases (e.g. HCl).This can beco-
me very critical when the pump is exposed to air. Depo-
sits can be avoided in many processes by heating the
pump with TMS (Temperature Management System).
The TMS is integrated in all CT-versions. The purpose of
the TMS is to keep the pump temperature in a constant
range. To achieve the temperature the pump is equipped
with a heaterband.
Some media ( e.g. metall organic compounds ) can
decompose at the hot surface of the pump and build lay-
ers. Please direct any inqueries to the manufacturer.
Caution
In order to handle gases or media (e.g.
AlCl
3
, WOCl
4
) which can form deposits insi-
de the pump it is required to use the TMS
(Temperature Management System). The
temperature selected for such processes
has to be set to the maximum value.
Ignition danger
During operation the pressure inside the MAG is so low
that there is no danger of ignition (at pressures below
about 100 mbar). A hazardous condition will be created
if flammable mixtures enter the hot pump at pressures
above 100 mbar. During operation the pump can reach
temperatures as high as 120
°
C (248
°
F). If the pump is
damaged, sparks could occur which could ignite explosi-
ve mixtures.
