Automated semiconductor processing system

Abstract

An automated semiconductor processing system has an indexer bay perpendicularly aligned with a process bay within a clean air enclosure. An indexer in the indexer bay provides stocking or storage for work in progress semiconductor wafers. Process chambers are located in the process bay. A process robot moves between the indexer bay and process bay to carry semi-conductor wafers to and from the process chambers. The process robot has a robot arm vertically moveable along a lift rail. Semiconductor wafers are carried offset from the robot arm, to better avoid contamination. The automated system is compact and requires less clean room floor space.

1 . A process robot for moving articles in an automated processing system, comprising: 
 a lift unit;    an elbow joint on the lift unit;    a forearm attached to the lift unit at the elbow joint;    a wrist joint attached to the forearm;    an end effector for holding articles to one side of the forearm and attached to the forearm at the wrist joint, with the process robot moveable into an overhand position wherein the wrist joint is above the elbow joint, and moveable into an underhand position wherein the wrist joint is below the elbow joint.    
     
     
         2 . The process robot of  claim 1  further comprising a vertical lift rail on the lift unit, with the elbow joint moveable along the lift rail via a lift motor.  
     
     
         3 . The process robot of  claim 1  wherein the end effector is displaced to one side of the wrist joint and the elbow joint, so that neither the wrist joint or the elbow joint is positionable vertically above the end effector, regardless of the orientation of the process robot.  
     
     
         4 . The process robot of  claim 1  further comprising an elbow drive motor in the elbow joint and linked to the forearm, for pivoting the forearm relative to the lift unit.  
     
     
         5 . The process robot of  claim 1  further comprising a wrist joint motor in the wrist joint, for pivoting the end effector relative to the forearm.  
     
     
         6 . The process robot of  claim 5  further comprising a motor amplifier in the lift unit and electrically connected to the wrist joint motor.  
     
     
         7 . The process robot of  claim 1  further comprising a lateral rail, and a linear drive motor for moving the lift unit along the lateral rail.  
     
     
         8 . The process robot of  claim 1  further comprising a pair of spaced apart wafer holders on the end effector.  
     
     
         9 . The process robot of  claim 1  further comprising a counterbalance exerting an upward force on the elbow.  
     
     
         10 . The process robot of  claim 9  where the counterbalance comprises a gas spring.  
     
     
         11 . A process robot for moving articles in an automated processing system, comprising: 
 a lateral rail;    a lift unit moveable horizontally along the lateral rail;    an arm assembly supported and moveable vertically on the lift unit, with the arm assembly including an elbow joint, a forearm attached to the elbow joint, a wrist joint on the forearm, and an end effector attached to the wrist joint, for holding articles to one side of the wrist joint, the forearm and the elbow joint.    
     
     
         12 . The process robot of  claim 11  further comprising a vertical lift rail on the lift unit, with the arm assembly moveable along the lift rail via a lift motor.  
     
     
         13 . The process robot of  claim 11  further comprising an elbow drive motor in the elbow joint and linked to the forearm, for pivoting the forearm relative to the lift unit.  
     
     
         14 . The process robot of  claim 11  further comprising a wrist joint motor in the wrist joint, for pivoting the end effector relative to the forearm.  
     
     
         15 . The process robot of  claim 11  further comprising counterbalance means on the lift unit for constantly exerting a counterbalancing upward force on the arm assembly.  
     
     
         16 . A process robot for moving articles in an automated processing system, comprising: 
 a lateral rail;    a lift unit supported on the lateral rail;    a liner drive motor for moving the lift unit horizontally along the lateral rail;    an arm assembly supported on the lift unit;    a lift motor in the lift unit for moving the arm assembly vertically on the lift unit;    with the arm assembly including an elbow drive motor within an elbow housing, a forearm having a first end attached to the elbow drive motor, a wrist drive motor within a wrist housing on a second end of the forearm, and an end effector attached to the wrist drive motor, for holding articles to one side of the wrist housing, the forearm and the elbow housing; and    a counterbalance attached to the lift unit and the arm assembly.    
     
     
         17 . The process robot of  claim 16  further comprising a vertical lift rail on the lift unit, with the arm assembly moveable along the lift rail via a lift motor in the lift unit.  
     
     
         18 . The process robot of  claim 16  further comprising a gear reduction between the elbow drive motor and the forearm.  
     
     
         19 . The process robot of  claim 16  wherein the elbow housing can move only linearly up and down on the lift unit.  
     
     
         20 . The process robot of  claim 16  wherein all movements of the process robot are performed only via one or more of the linear drive motor, the lift motor, the elbow drive motor, and the wrist drive motor.  
     
     
         21 . A robot unit for use in an automated processing system, comprising: 
 a robot arm assembly having an article support for holding articles, first rotary drive means connecting the article support to an arm segment, and second rotary drive means connected with the arm segment;    lifting means for moving the entire robot arm assembly vertically; and    lateral drive means for moving the entire robot arm assembly and the lifting means horizontally.