Multiple independent robot assembly and apparatus for processing and transferring semiconductor wafers

Abstract

A robot assembly including multiple independently operable robot assemblies are provided for use in semiconductor wafer processing. The robot assembly includes independent co-axial upper and lower robot assemblies adapted to handle multiple objects. The upper robot is stacked above the lower robot and the two robots are mounted concentrically to allow fast wafer transfer. Concentric drive mechanisms may also be provided for imparting rotary motion to either rotate the robot assembly or extend an extendable arm assembly into an adjacent chamber. Each robot can be either a single blade robot or a dual blade robot. Also provided is an apparatus for processing semiconductor wafers comprising a pre/post process transfer chamber housing multiple independent robot assemblies and surrounded by a plurality of pre-process chambers and post process chambers. A process transfer chamber is connected to the pre/post process transfer chamber by cooling chambers, and is otherwise surrounded by a plurality of process chambers. Multiple independent robot assemblies are also provided within the process transfer chamber. Within each process, pre-process and post-process chamber is an apparatus for holding a plurality of stacked wafers. The apparatus includes a wafer lifting and storing apparatus exhibiting a plurality of vertically movable lift pins surrounding the chamber pedestal. The lift pins are configured to receive and hold a plurality of stacked wafers, preferably two, therein. Each one of the plurality of lift pins preferably comprises a lower lift pin segment exhibiting a lower wafer support surface proximal to the upper end thereof, and an upper lift pin segment hingedly connected to the lower lift pin segment and exhibiting an upper wafer support surface proximal to an upper end thereof.

We claim:  
     
         1 . An apparatus for transferring objects, such as semiconductor wafers, composing: 
 a first article transfer assembly moveable about a central axis;    a second article transfer assembly spaced a distance apart from and coaxial with said first article transfer assembly and also moveable about said central axis, said first article transfer assembly being moveable about said central axis independently of said second article transfer assembly, where in each article transfer assembly includes an object support moveable about said central axis.    
     
     
         2 . The apparatus for transferring objects according to  claim 1 , wherein said first article transfer assembly comprises a first pair of extendable arm assemblies and said second article transfer assembly comprises a second pair of extendable arm assemblies.  
     
     
         3 . The apparatus for transferring objects according to  claim 2 , wherein each of said first pair of extendable arm assemblies and said second pair of extendable arm assemblies comprises: 
 a first drive arm moveable about said central axis;    a second drive arm moveable about said central axis;    a first pair of strut arms articulated to said first and second drive arms;    a second pair of strut arms articulated to said first and second drive arms;    a first object support coupled to said first pair of strut arms; and    a second object support coupled to said second pair of strut arms.    
     
     
         4 . The apparatus for transferring objects according to  claim 3 , wherein each of said first and second article transfer assemblies further comprises: 
 a first drive member for moving said fist drive arm and said second drive arm about sold central axis and thereby move said first object support between a first position and a second position about a central axis and a second drive member for independently moving said second object support between a first and second position about a central axis.    
     
     
         5 . The apparatus for transferring objects according to  claim 4 , further including a hub, and wherein each of said first and second drive members includes a motor located within said hub in an environment sealed from the environment within which said first and second extendible wall assemblies are maintained, and a coupler adjacent said hub and connected to said extendable arm assembly within the environment within which said extendable arm assemblies are maintained, each of said couplers operatively coupled to one of said first and second extendable arm assemblies to impart motion thereto.  
     
     
         6 . The apparatus for transferring objects according to  claim 5 , wherein each of said couplers include a ring connected to a drive arm of said extendable arm assemblies, and each of said motors is magnetically coupled, through said hub, to one of said rings.  
     
     
         7 . The apparatus for transferring objects according to  claim 2 , wherein said first pair of extendable arm assemblies and said second pair of extendable arm assembles are located within a transfer chamber; said transfer chamber being connected to one or more adjacent process chambers.  
     
     
         8 . The apparatus for transferring objects according to  claim 7 , wherein said first article transfer assembly is connected to an upper superstructure of said transfer chamber and said second article transfer assembly is connected to a bottom wall of the transfer chamber.  
     
     
         9 . The apparatus for transferring objects according to  claim 8 , wherein said hub comprises a central column connecting said first article transfer assembly to said second article transfer assembly.  
     
     
         10 . The apparatus for transferring objects according to  claim 9 , wherein said first extendable arm assembly is located above said second extendable arm assembly within a transfer chamber.  
     
     
         11 . The apparatus for transferring objects according to  claim 10 , wherein said transfer chamber is connected to one or more adjacent process chambers by a corresponding one or more valve assemblies, and said second article transfer assembly is connected to a bottom wall of the transfer chamber.  
     
     
         12 . The apparatus for transferring objects according to  claim 9 , wherein each of said first extendable arm assembly and said second extendable arm assembly comprises: 
 a first drive arm rotatable about said central axis;    a second drive arm rotatable about said central axis;    a pair of strut arms articulated to said first and second drive arms; and    an object support member pivotally coupled to said pair of strut arms.    
     
     
         13 . The apparatus for transferring objects according to  claim 12 , wherein each of said first and second article transfer assemblies further comprises: 
 independent drive members for rotating said first drive arm and said second drive arm to move said object support member between a first position and a second position relative to the central axis.    
     
     
         14 . The apparatus for transferring objects according to  claim 13 , wherein said hub comprises a central column connecting said first article transfer assembly to said second article transfer assembly.  
     
     
         15 . The apparatus for transferring objects according to  claim 14 , wherein said first extendable arm assembly is located above said second extendable arm assembly within a transfer chamber; the drive member of said first article transfer assembly being located above said first extendable arm assembly and the drive member of said second article transfer assembly being located below said second extendable arm assembly.  
     
     
         16 . The apparatus for transferring objects according to  claim 15 , wherein said transfer chamber is connected to one or more adjacent process chambers by a corresponding one or more valve assemblies, and said second article transfer assembly is connected to a bottom wall of the transfer chamber.  
     
     
         17 . The apparatus for transferring objects according to  claim 13 , wherein said drive means comprises: 
 a first article transfer assembly motor coupled to said first extendable arm assembly by a first pair of hollow drive shafts;    a second article transfer assembly motor coupled to said second extendable arm assembly by a second pair of hollow drive shafts; said second hollow drive shafts being concentric with said first hollow drive shafts.    
     
     
         18 . The apparatus for transferring objects according to  claim 17 , wherein said first extendable arm assembly is located above said second extendable arm assembly within a transfer chamber, and said first and second motors are located below the transfer chamber.  
     
     
         19 . The apparatus for transferring objects according to  claim 18 , wherein said first motor is located below said second motor and said second motor shaft surrounds said first motor shaft.  
     
     
         20 . The apparatus for transferring objects according to  claim 9 , wherein each of said first extendable arm assembly and said second extendable arm assembly comprises: 
 a first drive arm having a first end slidably connected to said central hub disposed about said central axis;    a secondary arm having a first end slidably connected to said central hub; and    an object support member pivotally coupled to said first drive arm and said secondary arm.    
     
     
         21 . The apparatus for transferring objects according to  claim 20 , further comprising: 
 a magnetic coupling coupling each one of said first ends of said drive arms through said central hub to a motor disposed within said central hub.    
     
     
         22 . The apparatus for transferring objects according to  claim 20 , wherein said object support member of said extendable arm assembly is horizontally co-planar with the object support member of said second extendable arm assembly.  
     
     
         23 . An apparatus for transferring objects between multiple positions within an enclosure, comprising: 
 a first object transfer assembly located within the enclosure;    a second object transfer assembly located within the enclosure;    at least one object rest location accessible to the enclosure and to said first object transfer assembly and said second object transfer assembly; and    a drive member operatively coupled to said first object transfer assembly and said second object transfer assembly to enable independent movement of said first object transfer assembly relative to said second object transfer assembly.    
     
     
         24 . The apparatus of  claim 23 , wherein said drive member includes at least one cylindrical wall section, sold cylindrical wall section extending inwardly of said enclosure and defining a volume isolated from the environment of the enclosure.  
     
     
         25 . The apparatus of  claim 24 , further including a first drive assembly located at least partially within said volume and operatively coupled to said first object transfer assembly and a second drive assembly located at least partially within said volume and operatively coupled to said second object transfer assembly.  
     
     
         26 . The apparatus of  claim 25 , wherein said operative coupling of said drive assemblies to said transfer assemblies is a magnetic coupling through said wall.  
     
     
         27 . The assembly of  claim 26 , wherein at least one of said object transfer assemblies includes a frog leg mechanism having a first end coupled to said drive assemblies through said wall and a second end supporting an object support member thereon; and 
 said drive assembly includes a first magnetic drive element and a second magnetic drive element providing magnetic coupling to said first end of said frog leg mechanism; whereby    movement of said magnetic drive mechanism in a common direction with respect to said central axis enables motion of said object transfer assembly with a constant distance between said first end and second end of said frog leg assembly, and movement of said magnetic drive elements in an opposed direction with respect to said central axis enables a change in the distance between first and second ends of said frog leg assembly.    
     
     
         28 . The apparatus of  claim 27 , wherein at least one of said object transfer assemblies includes: 
 a drive arm having a First end coupled to said drive member and a second end pivotally connected to an object support member;    a secondary arm having a first end coupled to said drive member and a second end pivotally connected to said drive arm at a position intermediate of said first and second end thereof; and    said object support member pivotally connected to said secondary arm at a position intermediate of said first and second ends thereof.    
     
     
         29 . The apparatus of  claim 28 , wherein said drive member includes: 
 a first drive element and a second drive element, said first drive element coupled to said first end of said drive arm and said second drive element coupled to said first end of said secondary arm; and whereby    movement of said first ends of said drive arm and said secondary arm in the same direction with respect to said wall enables movement of said object support member at a constant distance from said wall, and movement of said first ends of said drive arm and secondary arm in opposed directions enables a change in the location of said object support member relative to said wall.    
     
     
         30 . The apparatus of  claim 29 , further including: 
 a hub extending about the axis and defining a volume;    at least a fist drive member at least partially received within said volume and coupled through said hub to a first driven member within the enclosure and a second drive member at least partially received within said volume and coaxially disposed With said first drive member coupled through said hub to a second driven member; and    said first driven member and said second driven member coupled to said first transfer assembly in said enclosure.    
     
     
         31 . The apparatus of  claim 30 , wherein said first transfer assembly includes a first arm having a first portion coupled to said first driven member and a second portion; 
 a second arm having a first portion coupled to said second portion of said first arm and a second portion; and    an object receiving member coupled to said second portion of said second arm.    
     
     
         32 . The apparatus of  claim 31 , wherein said first transfer assembly further includes a third arm having a first portion coupled to said second driven member and a second portion; and 
 a fourth arm having a first portion coupled to said second portion of said first arm and a second portion coupled to said object receiving member.    
     
     
         33 . The apparatus of  claim 32 , wherein said fast and second driven members are annular rings disposed about the hub; and 
 movement of said driven members in opposed directions enables retraction and extension of said object receiving member of said first transfer assembly with respect to said axis and movement of said driven members in the same direction enables movement of said object receiving member of said first transfer assembly in at least a portion of an orbit about said axis.    
     
     
         34 . The apparatus of  claim 33 , further including: 
 a third driving member coupled to a third driven member in the enclosure and a fourth driving member coupled to a fourth driven member in the enclosure;    said second transfer assembly includes a first arm having a first portion coupled to said third driven member and a second portion;    a second arm having a first portion coupled to said second portion of said first arm and a second portion;    a third arm having a first portion coupled to said fourth driven member and a second portion;    a fourth arm having a first portion coupled to said second portion of said first arm and a second portion; and    an object receiving member coupled to said second portions of said second and fourth arms.    
     
     
         35 . The apparatus of  claim 34 , further including: 
 at least one object rest position within said enclosure, said object rest position accessible to the object receiving members of said first transfer assembly and second transfer assembly both simultaneously and independently.    
     
     
         36 . The apparatus of  claim 34 , wherein said first transfer assembly further includes: 
 a fifth arm having a first portion coupled to said second end of said first arm and a second portion;    a sixth arm coupled to said second end of said third arm and a second portion; and    a second object receiving member coupled to said second ends of said fifth and sixth arms.    
     
     
         37 . The apparatus of  claim 34 , wherein said driving members are coupled to drive motors, and each of said motors is suspended from said enclosure.  
     
     
         38 . The apparatus of  claim 34 , wherein said driving members are coupled to drive motors, and said drive motors for driving said first and second driving members are supported over said enclosure and said drive motors for driving said third and fourth driving members are suspended from said enclosure.  
     
     
         39 . The apparatus of  claim 34 , wherein said driving members are coupled to drive motors, and said drive motors are at least partially received in a hub extending across said enclosure.  
     
     
         40 . The apparatus of  claim 39 , wherein the enclosure includes an upper and lower wall, and said hub spans the space between said upper and said lower walls.  
     
     
         41 . The apparatus of  claim 29 , wherein the enclosure is a transfer chamber of a semiconductor processing system.  
     
     
         42 . The apparatus of  claim 34 , wherein the object receiving member is an end effector for receiving a semiconductor wafer.  
     
     
         43 . A method of transferring objects between a plurality of positions in an enclosure, comprising: 
 providing a first object transfer assembly having an object support positionable at multiple positions about an axis;    providing a second object transfer assembly having an object support positionable at multiple positions about said axis;    coaxially positioning said first and second object transfer assemblies about said axis; and    moving said object support of said first object transfer assembly independently of the position of said object support of said second object transfer assembly.    
     
     
         44 . The method of  claim 43 , including the additional steps of; 
 providing at least one object storage location accessible to the enclosure;    moving the object support of the first object transfer assembly to access said storage location while independently positioning the object support of the second object transfer assembly.    
     
     
         45 . The method of  claim 44 , wherein the step of positioning the object support of the second object transfer assembly includes: 
 moving the object support of the second object transfer assembly.    
     
     
         46 . The method of  claim 44 , wherein the step of positioning the object support of the second object transfer assembly includes: 
 maintaining the object support of the second object transfer assembly in a stationary position while the object support of the first object transfer assembly is moving.    
     
     
         47 . The method of  claim 44 , wherein the step of positioning the object support of the second object transfer assembly includes: 
 maintaining the object support of the second object transfer assembly in a stationary position while the object support of the first object transfer assembly is moving in an arcuate path about the axis.    
     
     
         48 . The method of  claim 44 , wherein the step of positioning the object support of the second object transfer assembly includes: 
 maintaining the object support of the second object transfer assembly in a stationary position while the object support of the first object transfer assembly is moving in a linear path.    
     
     
         49 . The method of  claim 44 , wherein the step of positioning the object support of the second object transfer assembly includes: 
 maintaining the object support of the second object transfer assembly in a stationary position while the object support of the first object transfer assembly is moving away from the axis.    
     
     
         50 . The method of  claim 44 , wherein the step of positioning the object support of the second object transfer assembly includes: 
 maintaining the object support of the second object transfer assembly in a stationary position while the object support of the first object transfer assembly is moving toward the axis.    
     
     
         51 . The method of  claim 44 , including the additional steps of moving the object support of the first object transfer assembly in a clockwise direction about the axis while simultaneously moving the object support of the second object transfer assembly in a counterclockwise direction about the axis.  
     
     
         52 . The method of  claim 51 , including the additional step of passing one of the first and second object supports over the other of the first and second object supports.  
     
     
         53 . The method of  claim 44 , including the further step of simultaneously accessing the storage location with the first and the second object supports.  
     
     
         52 . The method of  claim 51 , including the additional steps of; 
 providing multiple object rest positions accessible to the object transfer assemblies; and    simultaneously accessing different object rest positions with the first and second object support members.    
     
     
         53 . An apparatus for transferring semiconductor wafers between chambers adjacent to a transfer chamber, said wafer transfer apparatus comprising: 
 a lower wafer transfer robot movable about a central axis and connected to a bottom wall of said transfer chamber comprising: 
 a first extendable arm assembly located within said transfer chamber and comprising: 
 a first drive arm movable about said central axis;  
 a second drive arm movable about said central axis;  
 a pair of strut arms articulated to said first and second drive arms; and  
 a wafer holding blade pivotally coupled to said pair of strut arms; and  
 
 a drive motor located below said first extendable arm assembly and connected to an end of said first drive arm and end of said second drive arm for imparting motion to the ends thereof which is in an orbital path about said axis to enable linear movement of said wafer blade between an extended position and a retracted position;  
   an upper wafer transfer robot independently movable from and coaxially aligned with said lower wafer transfer robot, and comprising: 
 a second extendable arm assembly located within said transfer chamber above said first pair of extendable arm assemblies and comprising: 
 a first drive arm movable about said central axis;  
 a second drive arm movable about said central axis:  
 a pair of strut arms articulated to said first and second drive arms;  
 a wafer holding blade pivotally coupled to said pair of strut arms; and  
 
 a drive motor located above said second extendable arm assembly and connected to an end of said first drive arm and an end of said second drive arm for imparting motion thereto in an orbital path about said axis to enable linear movement of said wafer blade between an extended position and a retracted position; and  
   a central column connecting said first wafer transfer robot to said second wafer transfer robot.    
     
     
         54 . An apparatus for transferring semiconductor wafers between chambers adjacent to a transfer chamber, said wafer transfer apparatus comprising: 
 a first wafer transfer robot movable about a central ads comprising: 
 a first extendable arm assembly located within sold transfer chamber and comprising: 
 a first drive arm movable about said central axis;  
 a second drive arm movable about said central axis;  
 a pair of strut arms articulated to said first and second drive arms: and  
 a wafer holding blade pivotally coupled to said pair of strut arms; and  
 
 a drive motor located below said transfer chamber and coupled to an end of said first extendable arm assembly by a first hollow drive shaft for imparting motion thereto in an orbital path about said axis to enable linear movement of said wafer blade between an extended position and a retracted position;  
   a second wafer transfer robot independently movable from and coaxial with said first wafer transfer robot, and comprising: 
 a second extendable arm assembly located within said transfer chamber below said First pair of extendable arm assemblies and comprising: 
 a first drive arm moveable about said central axis;  
 a second drive arm moveable about said central axis;  
 a pair of strut arms articulated to said first and second drive arms;  
 a wafer holding blade pivotally coupled to said pair of strut arms; and  
 
 a drive motor located below said transfer chamber, and coupled to said second extendable arm assembly by a second hollow drive shaft, which is concentric with and surrounds said first hollow drive shaft, for imparting motion thereto to linearly move said wafer blade between an extended position and a retracted position.  
   
     
     
         55 . An apparatus for receiving a plurality of articles, such as semiconductor wafers, comprising: 
 a chamber having a chamber cavity therein for receiving said articles;    a pedestal centrally located and vertically movable within the chamber cavity;    an article lifting and storing apparatus comprising a plurality of vertically movable lift pins extendable between a retracted and an extended position with respect to the article receiving surface of said pedestal, said lift pins configured to receive and hold a plurality of stacked articles therein.    
     
     
         56 . The apparatus for receiving a plurality of articles according to  claim 55 , wherein said lift pins are configured to receive two stacked articles.  
     
     
         57 . The apparatus for receiving a plurality of articles according to  claim 56 , wherein each one of said plurality of lift pins comprise: 
 a lower lift pin segment exhibiting a lower article support surface proximal to the upper end thereof;    can upper lift pin segment hingedly connected to said lower lift pin segment and exhibiting an upper article support surface proximal to an upper end thereof.    
     
     
         58 . The apparatus for receiving a plurality of articles according to  claim 57 , further comprising an actuating member to move said upper lift pin segment to expose said lower lift pin segment to an article.  
     
     
         59 . The apparatus for receiving a plurality of articles according to  claim 57 , further comprising: 
 at least one pedestal pin extending outwardly from said pedestal to contact said upper lift pin segment as the position of the pedestal is changed wit respect to said lift pin segment, to move the upper lift pin assembly from a closed position to an open position.    
     
     
         60 . The apparatus for receiving a plurality of articles according to  claim 59 , further comprising a plurality of closing pins extending inwardly toward said lift pins from a surface of said chamber, said closing pins configured to contact said upper lift pin assembly in the open position and move said upper lift pin assembly to the closed position.  
     
     
         61 . An apparatus for processing semiconductor wafers comprising: 
 a transfer chamber surrounded by a plurality of chambers having wafer rest positions therein;    a process transfer robot located within said transfer chamber, said transfer robot comprising a first wafer transfer assembly moveable about a central axis and capable of accessing at least one common wafer rest position and a second wafer transfer assembly moveable about said central axis independently of said first wafer transfer assembly and capable of accessing said wafer rest position.