Abstract: A valve structure without dead-legs is provided for controlling the flow of gases in a semiconductor fabrication facility. The valve structure comprises a conduit forming a loop with three ports. Flexible metallic diaphragms are selectively operable to open and close two of the ports.

Abstract: A gas cabinet manifold is free of dead-legs both during delivery of process gas to a semiconductor fabrication tool location and during purging of the manifold. The manifold includes three similar dual valve assembly blocks. Each valve assembly block includes two valves and each of the valves has a valve chamber in which are formed three ports. Each valve also includes a mechanism for selectively closing one of its three ports. Each of the valves has one of its non-closeable ports connected via a conduit to a corresponding non-closeable port of the other valve, and the other non-closeable ports are connected by a second conduit which is connected by a third conduit to a port by which gas may be introduced into the valve block. A vacuum venturi or other vacuum source is used to vent process gas from a high pressure area of the manifold by way of a pressure regulator and a low pressure area of the manifold.

Abstract: A system including a plurality of gas flow control units in cabinets which are connected to distribute process gas, on demand, to a plurality of utilization locations known as "tool" locations in a semi-conductor manufacturing plant. Transducers are used in the system to measure pressures and other control parameters. Zero calibration of the transducers is provided by automatically subjecting each transducer to a reference computer routine to compute the difference between the standard value and the transducer output, and store the difference as an "offset" to correct the output of the transducer. Thus, re-calibration is performed simply and quickly, at a relatively low labor cost and with relatively little downtime for the system.

Abstract: A system including a plurality of gas flow control units in cabinets which are connected to distribute process gas, on demand, to a plurality of utilization locations known as "tool" locations in a semi-conductor manufacturing plant. Transducers are used in the system to measure pressures and other control parameters. Zero calibration of the transducers is provided by automatically subjecting each transducer to a reference computer routine to compute the difference between the standard value and the transducer output, and store the difference as an "offset" to correct the output of the transducer. Thus, re-calibration is performed simply and quickly, at a relatively low labor cost and with relatively little downtime for the system.

Abstract: 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.

Abstract: Gas flow control units in cabinets are connected to distribute process gas, on demand, to a plurality of utilization locations known as "tool" locations in a semi-conductor manufacturing plant. Each gas flow control cabinet has an exhaust duct which connects to an exhaust duct in the plant through which waste gases from the cabinet are exhausted by a fan to the atmosphere. Low flow alarm signals are generated if the exhaust flow is below a desired level. A programmable controller is provided for controlling the alarm function according to the size of the exhaust ducting from the plant so as to facilitate installation and operation of each cabinet in a variety of locations with different duct sizes.

Abstract: A plurality of gas flow control units in cabinets are connected to distribute process gas, on demand, to a plurality of utilization locations known as "tool" locations in a semi-conductor manufacturing plant. Each gas flow control unit is connected to a single tool interface controller over a single communications cable. The status and operational characteristics of the individual units are communicated through the tool interface controller to a supervisory control computer by means of polling. Each flow control cabinet has its own data processor, and can be operated alone. Also, the supervisory computer can be used to operate each cabinet, as well as to monitor operations of the system. Gas demand and other signals are communicated from each tool location to the control units through a single cable connected to the interface controller, thus reducing the original wiring cost.