OIPT Systems
Oxford Instruments Plasma Technology
System Manual
5.
Nitrogen
Nitrogen is required to vent and purge process chambers, load locks and pumps.
2 MICRON
FILTER
REGULATOR
1/4"
SWAGELOK
CONNECTOR
TO PLASMALAB
OR IONFAB
SYSTEM
TO PUMP
PURGE
CONNECTOR
0 TO 1 SLM
FLOW CONTROL
ROTAMETER
(IF REQUIRED)
Fig 5.1: Recommended nitrogen supply installation
Semiconductor grade fittings and pressure regulators, together with electropolished
stainless steel tube must be used to ensure that gas quality is not degraded. Purges to
turbo pumps are supplied by OIPT as part of the system. The customer will usually need
to fit a purge to the rotary pump. See below.
5.1
Mandatory specifications for Nitrogen supplies
•
Pipework fittings and
pressure regulators:
Semiconductor grade
•
Gas handling tubing:
Electropolished stainless steel
•
Purity:
At least 99.99% or higher to satisfy process
requirements.
•
Filtration:
2 micron filter mounted adjacent to the system.
•
Regulation:
0.5 to 5 bar (7.5 to 75 psig)
•
Minimum pressure at input to
system:
3 bar (45 psig). Certain pumps, for example
Edwards Drystar pumps, may need up to 5 bar
(75psig) to ensure satisfactory purging. Check
with the vendor's instructions.
•
Rotary pump purging
It is the customer’s responsibility to ensure that a rotary pump purge connection is
fitted and used correctly. This is needed to ensure the protection of the pumping
system from the customer’s process, and may also be required by local safety
regulations. Because customers’ requirements vary, components are not supplied
automatically by OIPT. Kits of parts are available if required. Contact OIPT for further
information.
It may be safe to omit this feature on certain systems, such as Ionfab machines
running inert gas processes. However, unless the customer has written agreement on
this point from OIPT, any damage caused by the omission cannot be covered by the
system warranty.
Services Specifications
Issue 21: January 10
Page 14 of 22
Printed: 6-Jan-10, 8:53
Summary of Contents for OpAL
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