Patent ID: 6343239
Filing Date: 2002-01-29
Classification: H01L

Abstract:
A transportation method for substrate wafers wherein substrate wafers are transported between transportation chamber s attached to processing apparatuses and holding an inert gas atmosphere using a transportation robot provided with a storage chamber which can store substrate wafers under an inert gas atmosphere, comprising the steps of:disposing a connection chamber between the storage chamber and the transportation chamber, wherein the volume of the storage chamber, the transportation chamber, and the connection chamber are respectively V1 [cm3], V2 [cm3], and V3 [cm3], the ratio of impurities in each chamber are respectively &ggr;1, &ggr;2, and &ggr;3, and the entire surface area of the substrate wafers is S [cm3]; opening the gate of the storage chamber and transportation chamber after introducing an inert gas into said connection chamber under a condition of lower pressure, and placing and removing substrate wafers between the storage chamber of said transportation robot and the transportation chamber of the processing apparatus when the condition 2.7Ã—1019 [molecules/cm3]Ã—(V1Ã—&ggr;1+V2Ã—&ggr;2+V3Ã—&ggr;3) &lE;1013 [molecules/cm2] Ã— S â€ƒis satisfied.