NITROGEN GAS SUPPLY SYSTEM

摘要

A nitrogen gas supply system which can efficiently supply nitrogen gas to a wafer processing unit 31 for applying a predetermined processing to wafers and to a nitrogen gas tunnel type wafer conveyor 32 for transporting the wafers to the wafer processing unit 31 through a gate valve 37 in sufficient and necessary amounts and with sufficient and necessary purity levels, respectively. This nitrogen gas supply system has a passage 38 for supplying high-purity nitrogen gas obtained in a cryogenic air separation plant 33 serving as a nitrogen gas generator to the wafer processing unit 31, a circulating passage 40 securing communication between outlet 32a and inlet 32b of the conveyor 32 via a purifier 39, and a replenishing passage 44 for replenishing nitrogen gas from a liquid nitrogen tank 36 to the circulating passage 40.