Patent ID: 7278812

Claim:
A wafer conveyance system for transporting one or more wafers that undergo, while being transported, different processes at a plurality of wafer processing apparatuses inside which one or more wafers are processed, the wafer conveyance system comprising: (a) a hermetically closed chamber that defines an isolated environment inside which a controlled atmosphere is provided; (b) at least one guide path provided inside the hermetically closed chamber; (c) a plurality of ducts that each communicate the isolated environment of the hermetically closed chamber with the inside of one wafer processing apparatus such that the hermetically closed chamber is in communication with one or more wafer processing apparatuses; (d) at least one mobile element being movable inside the hermetically closed chamber along the at least one guide path to transport one or more wafers from one wafer processing apparatus to another; (e) at least one arm provided on each mobile element, each arm being accessible to the inside of each wafer processing apparatus through a corresponding duct to load one or more wafers into a wafer processing apparatus and unload the same therefrom; and (f) a plurality of position sensors that detect positions of the at least one mobile element, the position sensors being deployed along each of the at least one guide path in such a manner that they are deployed at intervals close together when near the wafer processing apparatuses and deployed at wider intervals elsewhere.