Process gas distribution system and method

摘要

Gas flow control units in cabinet are connected to distribute process gas, on demand, to a plurality of utilization locations known as "tool" locations in a semi-conductor manufacturing plant. The flow control units are adapted to deliver process gas selectively from one of two supply tanks to any one or all of four different tool locations. Simple, fast, low-cost purging of the gas delivery conduits is provided to facilitate maintenance, gas cylinder changes, etc. Means are provided to enable pulse purging of the long gas delivery conduit from the cabinet to the tool when flow-through or other purging is not possible.