摘要 |
A semiconductor production system comprising a section for processing a substrate to fabricate a semiconductor device thereon, a passage for supplying the processing section with fluid required for processing the substrate, a section for outputting a set voltage corresponding to a set flow rate of the fluid, a mass flow controller located in the fluid supply passage and regulating flow rate of the fluid based on the set voltage, a first shut-off valve located on the upstream side of the mass flow controller in the fluid supply passage, and a second shut-off valve located on the downstream side of the mass flow controller in the fluid supply passage. The mass flow controller comprises a section for detecting actual flow rate of the fluid and outputting a corresponding detection voltage, a section for comparing the set voltage with the detection voltage and outputting an operation signal, and a section for regulating flow rate of the fluid based on the operation signal. Furthermore, a storage section is provided to store, a detection voltage being outputted from the detecting section of the mass flow controller when the first and second shut-off valves are closed. A correcting section is provided to correct the set voltage based on the detection voltage stored in the storage section to compensate for a variation in detection voltage when the actual flow rate of fluid is zero.
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