Wafer transfer apparatus and substrate transfer apparatus

Abstract

A wafer transfer apparatus is provided. In a minimum transformed state where a robot arm is transformed such that a distance defined from a 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, is set to exceed ½ of a length B in the forward and backward directions of an 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 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 ).

What is claimed is: 
     
       1. 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).   
     
     
       2. The wafer transfer apparatus according to  claim 1 , wherein the robot arm includes:
 a first link member which is connected at its one end with the base, configured to be angularly displaced about the pivot axis, and at which a first joint axis is set in parallel to the pivot axis;   a second link member which is connected at its one end with an other end of the first link member, configured to be angularly displaced about the first joint axis, and at which a second pivot axis is set in parallel to the pivot axis; and   a third link member which is connected at its one end with an other end of the second link member, configured to be angularly displaced about the second joint axis, and includes the robot hand at an other end of the third link member for holding the wafer,   wherein a first link distance L 1  defined as a distance from the pivot axis to an end of the first link member, which is farthest in a radial direction toward the first joint axis relative to the pivot axis, is set to exceed ½ of the allowable length (B−L 0 −E) and to be equal to or less than the allowable length (B−L 0 −E) (i.e., ((B−L 0 −E)/2<L 1 ≤B−L 0 −E).   
     
     
       3. The wafer transfer apparatus according to  claim 2 ,
 wherein a first axis-to-axis distance L 11  from the pivot axis to the first joint axis and a second axis-to-axis distance L 12  from the first joint axis to the second joint axis are set to be equal to each other, and   wherein a second link distance L 2  defined as a distance from the second joint axis to an end of the second link member, which is farthest in a direction toward the first joint axis relative to the second joint axis, is set to exceed ½ of the allowable length (B−L 0 −E) and to be equal to or less than the allowable length (B−L 0 −E).   
     
     
       4. The wafer transfer apparatus according to  claim 3 , wherein a third link distance L 3  defined as a distance from the second joint axis to an end of the third link member or a portion of the wafer, which is farthest in a radial direction relative to the second joint axis, is set to exceed ½ of the allowable length (B−L 0 −E) and to be equal to or less than the allowable length (B−L 0 −E). 
     
     
       5. The wafer transfer apparatus according to  claim 4 , wherein the first link distance L 1 , the second link distance L 2  and the third link distance L 3  are respectively set to be equal to the allowable length (B−L 0 −E). 
     
     
       6. The wafer transfer apparatus according to  claim 1 ,
 wherein the front opening includes four openings which are formed in the interface space forming portion, the four openings being arranged in left and right directions orthogonal to both the forward and backward directions and a direction of the pivot axis, and   wherein the FOUP opener includes four openers which are provided in order to open and close the four openings, respectively.   
     
     
       7. A substrate transfer apparatus for transferring a substrate, relative to a substrate processing apparatus for processing the substrate, 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 in predetermined forward and backward directions at an interval, the front wall having a first transfer port formed therein, and the rear wall having a second transfer port formed therein;   an opening and closing unit configured to open and close the first transfer port of the interface space forming portion; and   a substrate carrying robot located in the interface space and configured to carry the substrate between the first transfer port and the second transfer port,   wherein the substrate carrying robot includes:
 a base which is fixed to the interface space forming portion and at which a predetermined pivot axis is set; 
 a first link member which is connected at its one end with the base, configured to be angularly displaced about the pivot axis, and at which a first joint axis is set in parallel to the pivot axis; 
 a second link member which is connected at its one end with an other end of the first link member, configured to be angularly displaced about the first joint axis, and at which a second pivot axis is set in parallel to the pivot axis; 
 a third link member which is connected at its one end with an other end of the second link member, configured to be angularly displaced about the second joint axis, and includes a robot hand at an other end thereof for holding the substrate; and 
 a drive unit configured to drive each of the link members so that the link members are angularly displaced, individually, about each corresponding axis, 
   wherein the pivot axis is located nearer to the rear wall than to the front wall or nearer to the front wall than to the rear wall in the forward and backward directions, and   wherein a first link distance L 1  defined as a distance from the pivot axis to an end of the first link member, which is farthest in a radial direction toward the first joint axis 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<L 1 ≤B−L 0 ), and   the first link distance L 1  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., L 1 ≤B−L 0 −E).   
     
     
       8. 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  set to be greater by a predetermined gap length Q than a radius T 2  of an outer circumference of the first link member about the pivot axis (L 0 =T 2 +Q), 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  set to be greater by the predetermined gap length Q than the radius T 2  of an outer circumference of the first link member about 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).   
     
     
       9. The wafer transfer apparatus according to  claim 8 , wherein the robot arm includes:
 a first link member which is connected at its one end with the base, configured to be angularly displaced about the pivot axis, and at which a first joint axis is set in parallel to the pivot axis;   a second link member which is connected at its one end with an other end of the first link member, configured to be angularly displaced about the first joint axis, and at which a second pivot axis is set in parallel to the pivot axis; and   a third link member which is connected at its one end with an other end of the second link member, configured to be angularly displaced about the second joint axis, and includes the robot hand at an other end of the third link member for holding the wafer,   wherein a first link distance L 1  defined as a distance from the pivot axis to an end of the first link member, which is farthest in a radial direction toward the first joint axis relative to the pivot axis, is set to exceed ½ of the allowable length (B−L 0 −E) and to be equal to or less than the allowable length (B−L 0 −E) (i.e., ((B−L 0 −E)/2<L 1 ≤B−L 0 −E).   
     
     
       10. The wafer transfer apparatus according to  claim 9 ,
 wherein a first axis-to-axis distance L 11  from the pivot axis to the first joint axis and a second axis-to-axis distance L 12  from the first joint axis to the second joint axis are set to be equal to each other, and   wherein a second link distance L 2  defined as a distance from the second joint axis to an end of the second link member, which is farthest in a direction toward the first joint axis relative to the second joint axis, is set to exceed ½ of the allowable length (B−L 0 −E) and to be equal to or less than the allowable length (B−L 0 −E).   
     
     
       11. The wafer transfer apparatus according to  claim 10 , wherein a third link distance L 3  defined as a distance from the second joint axis to an end of the third link member or a portion of the wafer, which is farthest in a radial direction relative to the second joint axis, is set to exceed ½ of the allowable length (B−L 0 −E) and to be equal to or less than the allowable length (B−L 0 −E). 
     
     
       12. The wafer transfer apparatus according to  claim 11 , wherein the first link distance L 1 , the second link distance L 2  and the third link distance L 3  are respectively set to be equal to the allowable length (B−L 0 −E). 
     
     
       13. The wafer transfer apparatus according to  claim 8 ,
 wherein the front opening includes four openings which are formed in the interface space forming portion, the four openings being arranged in left and right directions orthogonal to both the forward and backward directions and a direction of the pivot axis, and   wherein the FOUP opener includes four openers which are provided in order to open and close the four openings, respectively.   
     
     
       14. A substrate transfer apparatus for transferring a substrate, relative to a substrate processing apparatus for processing the substrate, 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 in predetermined forward and backward directions at an interval, the front wall having a first transfer port formed therein, and the rear wall having a second transfer port formed therein;   an opening and closing unit configured to open and close the first transfer port of the interface space forming portion; and   a substrate carrying robot located in the interface space and configured to carry the substrate between the first transfer port and the second transfer port,   wherein the substrate carrying robot includes:
 a base which is fixed to the interface space forming portion and at which a predetermined pivot axis is set; 
 a first link member which is connected at its one end with the base, configured to be angularly displaced about the pivot axis, and at which a first joint axis is set in parallel to the pivot axis; 
 a second link member which is connected at its one end with an other end of the first link member, configured to be angularly displaced about the first joint axis, and at which a second pivot axis is set in parallel to the pivot axis; 
 a third link member which is connected at its one end with an other end of the second link member, configured to be angularly displaced about the second joint axis, and includes a robot hand at an other end thereof for holding the substrate; and 
 a drive unit configured to drive each of the link members so that the link members are angularly displaced, individually, about each corresponding axis, 
   wherein the pivot axis is located nearer to the rear wall than to the front wall or nearer to the front wall than to the rear wall in the forward and backward directions, and   wherein a first link distance L 1  defined as a distance from the pivot axis to an end of the first link member, which is farthest in a radial direction toward the first joint axis 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  set to be greater by a predetermined gap length Q than a radius T 2  of an outer circumference of the first link member about the pivot axis (L 0 =T 2 +Q), from the length B in the forward and backward directions of the interface space (i.e., B/2<L 1 ≤B−L 0 ), and   the first link distance L 1  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  set to be greater by the predetermined gap length Q than the radius T 2  of an outer circumference of the first link member about 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., L 1 ≤B−L 0 −E).   
     
     
       15. 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 a wafer 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 the robot arm, 
   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 (i.e., B/2<R),   the minimum rotation radius R is set to be equal to or less than an allowable length (B−E) to be obtained by subtracting 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 (i.e., R≤B−E), and the minimum rotation radius R is set so that the robot arm in the minimum transformed state cannot enter the robot invasion restricted region, and   the robot invasion restricted region is defined by a distance which the FOUP opener moves in the forward and backward directions of the interface space, wherein the FOUP opener opens and closes an opener-side door and a FOUP-side door.   
     
     
       16. 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 a wafer 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 the robot arm, 
   wherein a first link distance L1 is defined as a distance from the pivot axis to an end of a first link member that extends from the proximal end, the end of the first link member being farthest in a radial direction toward a first joint axis of the first link member relative to the pivot axis, and the first link distance L1 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 (i.e., B/2<L1),   the first link distance L1 is set to be equal to or less than an allowable length (B−E) to be obtained by subtracting 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 (i.e., L1≤B−E), and the first link distance L1 is set so that the first link member cannot enter the robot invasion restricted region, and   the robot invasion restricted region is defined by a distance which the FOUP opener moves in the forward and backward directions of the interface space, wherein the FOUP opener opens and closes an opener-side door and a FOUP-side door.   
     
     
       17. The wafer transfer apparatus according to claim 15, wherein
 the minimum rotation radius R is further set to be equal to or less than a second allowable length (B−E−L0) to be obtained by subtracting (i) the length E of the robot invasion restricted region and (ii) a distance L0 set equal to Q+T2 where Q is a predetermined gap length and T2 is a distance from the pivot axis to an outer surface of a first link member of the plurality of link members that is adjacent one of the front and rear walls, from the length B (i.e., R≤B−E−L0).   
     
     
       18. The wafer transfer apparatus according to claim 17, wherein
 the predetermined gap length Q defines a space that is separate from a space defined by the length E of the robot invasion restricted region, and the predetermined gap length Q is the length of a gap provided to prevent interference that would be otherwise caused by the robot.   
     
     
       19. The wafer transfer apparatus according to claim 18, wherein
 the outer surface of the first link member adjacent the one of the front and rear walls is on an opposite side of the pivot axis with respect to a first joint axis, the first link member and a second link member of the plurality of link members being arranged to pivot relative to each other about the first joint axis.   
     
     
       20. The wafer transfer apparatus according to claim 19, wherein
 the predetermined gap length Q extends from the outer surface and in a direction toward the adjacent one of the front and rear walls.   
     
     
       21. The wafer transfer apparatus according to claim 16, wherein
 the first link distance L1 is further set to be equal to or less than a second allowable length (B−E−L0) to be obtained by subtracting (i) the length E of the robot invasion restricted region and (ii) a distance L0 set equal to Q+T2 where Q is a predetermined gap length and T2 is a distance from the pivot axis to an outer surface of the first link member that is adjacent one of the front and rear walls, from the length B (i.e., L1≤B−E−L0).   
     
     
       22. The wafer transfer apparatus according to claim 21, wherein
 the predetermined gap length Q defines a space that is separate from a space defined by the length E of the robot invasion restricted region, and the predetermined gap length Q is the length of a gap provided to prevent interference that would be otherwise caused by the robot.   
     
     
       23. The wafer transfer apparatus according to claim 22, wherein
 the outer surface of the first link member adjacent the one of the front and rear walls is on an opposite side of the pivot axis with respect to the first joint axis, the first link member and a second link member of the plurality of link members being arranged to pivot relative to each other about the first joint axis.   
     
     
       24. The wafer transfer apparatus according to claim 23, wherein
 the predetermined gap length Q extends from the outer surface and in a direction toward the adjacent one of the front and rear walls.   
     
     
       25. 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 wafer carrying robot located in the interface space and configured to carry the wafer between the front opening and the rear opening; and   a FOUP opener including an opener-side door, the FOUP opener being configured to open and close a wafer container which includes a FOUP-side door and is located adjacent to the interface space and the front opening of the interface space forming portion, the FOUP opener being configured to open and close the opener-side door and the FOUP-side door, and movement of the FOUP opener during such opening and closing defining a robot invasion restricted region extending in the forward and backward directions,   wherein the wafer carrying robot includes:
 a base which is positioned relative 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 the robot arm, 
   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 between the front opening and the rear opening in the forward and backward directions, and   the minimum rotation radius R is set (i) to be equal to or less than a length between the opener-side door and the rear opening in the forward and backward directions, and (ii) so that the robot arm in the minimum transformed state cannot enter the robot invasion restricted region.   
     
     
       26. 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 wafer carrying robot located in the interface space and configured to carry the wafer between the front opening and the rear opening; and   a FOUP opener including an opener-side door, the FOUP opener being configured to open and close a wafer container which includes a FOUP-side door and is located adjacent to the interface space and the front opening of the interface space forming portion, the FOUP opener being configured to open and close the opener-side door and the FOUP-side door, and movement of the FOUP opener during such opening and closing defining a robot invasion restricted region extending in the forward and backward directions,   wherein the wafer carrying robot includes:
 a base which is positioned relative 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 the robot arm, 
   wherein a first link distance L1 is defined as a distance from the pivot axis to an end of a first link member that extends from the proximal end, the end of the first link member being farthest in a radial direction toward a first joint axis of the first link member relative to the pivot axis, and the first link distance L1 is set to exceed ½ of a length between the front opening and the rear opening in the forward and backward directions, and   the first link distance L1 is set (i) to be equal to or less than a length between the opener-side door and the rear opening in the forward and backward directions, and (ii) so that the first link member cannot enter the robot invasion restricted region.   
     
     
       27. The wafer transfer apparatus according to claim 15, wherein
 the front opening includes a plurality of front openings,   the FOUP opener includes a plurality of FOUP openers configured to open and close a plurality of wafer containers, and   the length E of the robot invasion restricted region is set for the plurality of FOUP openers.   
     
     
       28. The wafer transfer apparatus according to claim 27, wherein
 the plurality of FOUP openers is four FOUP openers.   
     
     
       29. The wafer transfer apparatus according to claim 25, wherein
 the front opening includes a plurality of front openings,   the FOUP opener includes a plurality of FOUP openers configured to open and close a plurality of wafer containers,   a length of the robot invasion restricted region is “E,” and   the length E of the robot invasion restricted region is set for the plurality of FOUP openers.   
     
     
       30. The wafer transfer apparatus according to claim 29, wherein
 the plurality of FOUP openers is four FOUP openers.   
     
     
       31. The wafer transfer apparatus according to claim 25, wherein
 the length between the front opening and the rear opening is “B,” a length of the robot invasion restricted region is “E,” and the minimum rotation radius R is further set to be equal to or less than an allowable length (B−E−L0) to be obtained by subtracting (i) the length E of the robot invasion restricted region and (ii) a distance L0 set equal to Q+T2 where Q is a predetermined gap length and T2 is a distance from the pivot axis to an outer surface of a first link member of the plurality of link members that is adjacent one of the front and rear walls, from the length B (i.e., R≤B−E−L0).   
     
     
       32. The wafer transfer apparatus according to claim 26, wherein
 the length between the front opening and the rear opening is “B,” a length of the robot invasion restricted region is “E,” and the first link distance L1 is further set to be equal to or less than an allowable length (B−E−L0) to be obtained by subtracting (i) the length E of the robot invasion restricted region and (ii) a distance L0 set equal to Q+T2 where Q is a predetermined gap length and T2 is a distance from the pivot axis to an outer surface of the first link member that is adjacent one of the front and rear walls, from the length B (i.e., L1≤B−E−L0).