Patent ID: 7874782

Claim:
A wafer transfer apparatus for transferring a wafer, comprising: an interface space forming portion defining an interface space, the interface space forming portion having a front wall and a rear wall which are arranged at a predetermined interval in forward and backward directions, the front wall having a front opening formed therein, and the rear wall having a rear opening formed therein; a FOUP opener configured to open and close the substrate container located adjacent to the interface space and the front opening of the interface space forming portion; and a wafer carrying robot located in the interface space and configured to carry the wafer between the front opening and the rear opening, wherein the wafer carrying robot includes: a base which is fixed to the interface space forming portion and at which a predetermined pivot axis is set; a robot arm having a proximal end and a distal end, the robot arm including a plurality of link members connected with one another in succession in a direction from the proximal end to the distal end, the proximal end being connected with the base, the distal end being provided with a robot hand for holding the wafer, the robot arm being configured to be angularly displaced about the pivot axis; and a drive unit configured to drive each of the link members of the robot arm so that the link members are angularly displaced, individually, about each corresponding axis, wherein, in a minimum transformed state where the robot arm is transformed such that a distance defined from the pivot axis to an arm portion which is farthest in a radial direction relative to the pivot axis is minimum, a minimum rotation radius R, as the distance defined from the pivot axis to the arm portion which is the farthest in the radial direction relative to the pivot axis, is set to exceed ½ of a length B in the forward and backward directions of the interface space, the length B corresponding to a length between the front wall and the rear wall of the interface space forming portion, and is further set to be equal to or less than a subtracted value (B−L 0 ) to be obtained by subtracting a distance L 0 in the forward and backward directions from the rear wall of the interface space forming portion to the pivot axis, from the length B in the forward and backward directions of the interface space (i.e., B/2<R≦B−L 0 ), and the minimum rotation radius R is set to be equal to or less than an allowable length (B−L 0 −E) to be obtained by subtracting the distance L 0 in the forward and backward directions from the rear wall of the interface space forming portion to the pivot axis and a length E of a robot invasion restricted region, which is set for the FOUP opener and is measured from the front wall in the forward and backward directions toward the rear wall, from the length B in the forward and backward directions of the interface space (i.e., R<B−L 0 −E).