OpAL Oxford Instruments Plasma Technology System Manual
3.12.3 Internal gas pod
The purpose of the internal gas pod is to provide two gases dedicated for inert gas
purging and inert gas bubbling of precursors. The controls are provided from a CAN unit
sited inside the main console. A further two gases which are process gases may be
housed inside the precursor cabinet. In the unlikely event that a leak occurs in the
precursor cabinet, an extraction collar at the rear of the case enables any leaked gas to be
safely removed by a laboratory extraction system. Selection of gases and flow rates are
determined by the system controller.
The outputs from the two gas lines dedicated for purge and bubbling are fed separately
into the chamber. The two process gases housed inside the precursor cabinet are
connected to the process chamber gas line.
Pneumatically operated shut-off valves in each gas line are driven by associated SMC
valves mounted on the associated gas pod CAN PCB. Each SMC valve is powered by
compressed air and controlled by signals from the system controller.
All gas pod functions are controlled by interlocks, refer to sub-section
3.6.2.2 for details.
A gas pod cover interlock microswitch disables all gas pod functions unless the cover is
correct
ly fitted.
A CAN (Controller Area Network) PCB is fitted, controlling the gas lines.
The Gas Pod CAN PCB receives signals from the system controller, to control the SMC
valves, and the Mass Flow Controllers (MFC) fitted in the gas lines. For a circuit diagram of
the Gas Pod CAN PCB, refer to the electrical drawings in Volume 2 of this manual.
.
WARNING
THE CONNECTION FROM THE GAS POD MANIFOLD TO THE PROCESS
CHAMBER SHOULD NOT INCLUDE ANY SHUT OFF VALVE, UNLESS
THIS HAS BEEN CLEARED WITH OXFORD INSTRUMENTS PLASMA
TECHNOLOGY. A BLOCKAGE HERE COULD CAUSE PROCESS GASES TO
MIX AND CROSS CONTAMINATE IN THE HIGH PRESSURE GAS
DELIVERY PIPEWORK.
Description
Issue 1: August 07 Page 3-38 of 46 Printed: 07 August 2009 07:42
To Next Page
