Wafer handling device and method for testing wafers

Abstract

A wafer handling device comprises metrology equipment ( 410, 420, 430, 440, 450, 460 ) for testing selected wafers as well as a stationary wafer storage system ( 300 ). The stationary wafer storage system ( 300 ) has a buffer ( 310 ) to store wafers and a load-and-unload station ( 320 ) to transfer selected wafers between the buffer ( 310 ) and wafer transport means ( 330 ). The wafer transport means are provided for transferring selected wafers between the load-and-unload station ( 320 ) and the metrology equipment ( 410, 420, 430, 440, 450, 460 ).

1 . A wafer handling device, comprising: metrology equipment for testing selected wafers, and a stationary wafer storage system, said stationary wafer storage system having a buffer for storing a plurality of wafers and at least a load-and-unload station for transferring said selected wafers between said buffer and wafer transport means, wherein said wafer transport means are provided for transferring one or more of said selected wafers between said load-and-unload station and said metrology equipment.  
     
     
         2 . The wafer handling device according to  claim 1 , wherein said wafer transport means comprise at least one robot.  
     
     
         3 . The wafer handling device according to  claim 1 , wherein said metrology equipment comprises one or more of the following stations: a particle monitoring station, a stress test station, a thickness test station, an X-ray fluorescence analysis station, an atomic force microscopy station, an orienter station, a map station, and an opaque film thickness test station.  
     
     
         4 . The wafer handling device according to  claim 1 , wherein said metrology equipment comprises groups formed by different test stations arranged adjacent to each other.  
     
     
         5 . The wafer handling device according to  claim 1 , wherein said metrology equipment comprises groups formed by different test stations arranged adjacent to each other, wherein said wafer transport means comprise robots, and wherein to each of said groups there is assigned one of said robots.  
     
     
         6 . The wafer handling device according to  claim 1 , further comprising intermediate storage means for storing wafers between testing steps performed by said metrology equipment.  
     
     
         7 . The wafer handling device according to  claim 1 , further comprising intermediate storage means for storing wafers between test steps performed by said metrology equipment, wherein said intermediate storage means comprise one or more pods.  
     
     
         8 . The wafer handling device according to  claim 1 , wherein said wafers are stored in said buffer within pods.  
     
     
         9 . A method for testing wafers, comprising the following steps: 
 a) selecting wafers to be tested from a plurality of wafers stored in a stationary storage system;    b) transferring at least some of said wafers to be tested from said stationary storage system to wafer transport means via a load-and-unload station assigned to said stationary storage system; and    c) transferring at least some of said wafers to be tested to metrology equipment by said wafer transport means and performing at least one test step.    
     
     
         10 . The method according to  claim 9 , further comprising the following steps: 
 d) transferring at least some of said wafers to be tested between at least some of different test stations forming said metrology equipment, and performing at least one further test step; and    e) transferring at least some of the wafers tested with step d) back to said load-and-unload station by said wafer transport means, for storing them in said stationary storage system.    
     
     
         11 . The method according to  claim 9 , wherein said step a) comprises selecting said wafers to be tested from different wafer lots.  
     
     
         12 . The method according to  claim 9 , wherein said metrology equipment comprises one ore more of the following stations: a particle monitoring station, a stress test station, a thickness test station, an X-ray fluorescence analysis station, an atomic force microscopy station, an orienter station, a map station, an opaque film thickness test station.  
     
     
         13 . The method according to  claim 9 , wherein said metrology equipment comprises groups formed by different test stations arranged adjacent to each other, wherein said wafer transport means comprise robots, and wherein to each of said groups there is assigned one of said robots.  
     
     
         14 . The method according to  claim 9 , wherein at least some of said wafers to be tested are stored in intermediate storage means between different test steps.