Apparatus for storing and moving a cassette

Abstract

A cassette stocker includes a plurality of cassette storage shelves positioned adjacent a cleanroom wall above a cassette docking station, and a cassette mover to carry a cassette between the shelves and the docking station. An interstation transfer apparatus includes an overhead support beam and a transfer arm adapted to carry a cassette between processing stations.

What is claimed is:  
     
         1 . An apparatus for storing cassettes, comprising: 
 a plurality of cassette storage shelves; and    a cassette mover to carry a cassette between the shelves and a docking station, the cassette mover including a support member positioned in front of the shelves and movable in a path adjacent to the shelves, and an end effector configured to engage the cassette, the end effector movably connected to the support member.    
     
     
         2 . The apparatus of    claim 1   , wherein the shelves are configured to be positioned adjacent a cleanroom wall.  
     
     
         3 . The apparatus of    claim 2   , wherein one or more of the shelves are positioned above the docking station.  
     
     
         4 . The apparatus of    claim 1   , further comprising a frame supporting the cassette storage shelves and the support member.  
     
     
         5 . The apparatus of    claim 4   , wherein the frame substantially fits below the docking station.  
     
     
         6 . The apparatus of    claim 1   , wherein a lower end of the support member is slidably connected to a frame.  
     
     
         7 . The apparatus of    claim 6   , wherein the end effector is joined to a first slider which slidably engages a first, vertical guide joined to the support member.  
     
     
         8 . The apparatus of    claim 7   , wherein the support member is joined to a second slider which slidably engages a second, horizontal guide joined to the frame.  
     
     
         9 . The apparatus of    claim 8   , further comprising a first lead screw engaging the first slider and a first drive motor to rotate the first lead screw and drive the first slider along the first guide to move the end effector vertically.  
     
     
         10 . The apparatus of    claim 9   , further comprising a second lead screw engaging the second slider and a second drive motor to rotate the second lead screw and drive the second slider along the second guide to move the support member and the end effector horizontally.  
     
     
         11 . The apparatus of    claim 1   , wherein the shelves are arranged in a vertical column above the docking station.  
     
     
         12 . The apparatus of    claim 1   , wherein the end effector includes a hook-shaped finger adapted to engage a bottom surface of a flange on a top of the cassette.  
     
     
         13 . The apparatus of    claim 1   , wherein each shelf includes a plurality of pins that project vertically from the shelf to engage corresponding indentations in the underside of the cassette.  
     
     
         14 . An apparatus for storing cassettes, comprising: 
 a plurality of cassette storage shelves positioned adjacent a wall above a plurality of cassette docking stations; and    a cassette mover to carry a cassette between the shelves and the docking stations, the cassette mover including a support member positioned in front of the shelves and movable in a plane parallel to the wall, and an end effector configured to engage the cassette, the end effector slidably connected to the support member.    
     
     
         15 . The apparatus of    claim 14   , wherein the shelves are arranged in a vertical column above each docking station.  
     
     
         16 . The apparatus of    claim 14   , wherein adjacent vertical columns of shelves are separated by a vertical channel, and the cassette mover is configured to transport a cassette to a selected support shelf by moving the cassettes vertically through the channel to position the cassette substantially adjacent and above the selected support shelf, and then horizontally to position the cassette over the selected support shelf.  
     
     
         17 . A semiconductor processing station, comprising: 
 a processing system to perform a fabrication step on a substrate;    an interface wall separating the processing system from a cleanroom;    a docking station located in the cleanroom to support a cassette;    an opening in the interface wall;    a wafer transfer robot to transfer the substrate through the opening between the docking station and the processing system;    a loading platform located in the cleanroom adjacent the docking station; and    a cassette stocker located in the cleanroom, the cassette stocker including, 
 i) a plurality of shelves aligned in a vertical column above the docking station, and  
 ii) a cassette mover to carry a cassette between the shelves, the loading platform, and the docking station, the cassette mover including a support member positioned in front of the shelves and movable in a path adjacent to the shelves, and an end effector slidably connected to the support member and configured to engage the cassette.  
   
     
     
         18 . A method of operating a processing station, comprising: 
 storing a plurality of cassettes on a plurality of cassette storage shelves adjacent a cleanroom wall above a docking station;    carrying one of the cassettes to the docking station with a cassette mover;    removing a substrate from the cassette; and    returning the cassette to the cassette storage shelves with the cassette mover.