摘要 |
An auto-switching sub-atmospheric pressure gas delivery system, for dispensing gas to a gas-consuming process unit, e.g., a semiconductor manufacturing tool. The gas delivery system uses a multiplicity of gas panels, wherein one panel is in active gas dispensing mode and supplying gas from a sub-atmospheric pressure gas source coupled to the flow circuitry of the panel. During the active gas dispensing operation in such panel, a second gas panel of the system undergoes purge, evacuation and fill transition to active gas dispensing condition, to permit switching to the second panel upon exhaustion of the sub-atmospheric pressure gas source coupled to the first gas panel without the occurrence of pressure spikes or flow perturbations.
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