Tool architecture for wafer geometry measurement in semiconductor industry

Abstract

A semiconductor equipment architecture WGT for wafer shape and flatness measurement is disclosed. The semiconductor equipment architecture WGT includes a reflective air-bearing chuck and a hybrid wafer thickness gauge. Also disclosed are the corresponding methods of measuring wafer shape and flatness using the architecture, the air-bearing chuck and the hybrid wafer thickness gauge.

1 - 10 . (canceled) 
     
     
         11 . An air-bearing chuck comprising:
 an array of pressure nozzles;   an array of vacuum nozzles; and   wherein the array of pressure nozzles and array of vacuum nozzles are in an axis symmetric and alternating arrangement, the arrangement forming a plurality of concentric rings.   
     
     
         12 . The air-bearing chuck of  claim 11 , wherein the air-bearing chuck is a 200 mm chuck. 
     
     
         13 . The air-bearing chuck of  claim 11 , wherein a tangential separation between the pressure nozzles and vacuum nozzles in each of the plurality of concentric rings is kept at a constant. 
     
     
         14 . The air-bearing chuck of  claim 11 , wherein there is an increase of an even number of nozzles in each of the plurality of concentric rings towards an edge of the air-bearing chuck. 
     
     
         15 . The air-bearing chuck of  claim 14 , wherein the even number of nozzles is on the order of 6. 
     
     
         16 . The air-bearing chuck of  claim 11 , wherein a flatness of the air-bearing chuck is 1.5 um. 
     
     
         17 . The air-bearing chuck of  claim 11 , further comprising a surface having a mirror like finish. 
     
     
         18 . The air-bearing chuck of  claim 11 , further comprising 3 wafer grippers, 2 of which fixed at 90 degrees apart. 
     
     
         19 . The air-bearing chuck of  claim 11 , wherein the distance between each pair of adjacent pressure nozzle and vacuum nozzle in each of the concentric rings is 9.0 mm; and
 Wherein the distance between each pair of adjacent pressure nozzle and vacuum nozzle in a radial direction is 11 mm.   
     
     
         20 . The air-bearing chuck of  claim 11 , further comprising stacked layers comprising:
 a vacuum manifold layer;   a pressure manifold layer; and   a top chuck layer on top of both the vacuum manifold layer and the pressure manifold layer, the top chuck layer comprises the array of vacuum nozzles and the array of pressure nozzles.   
     
     
         21 . The air-bearing chuck of  claim 20 , wherein the vacuum manifold layer comprises a plurality of vacuum channels; and
 wherein the top chuck layer comprises a plurality of vacuum through holes connecting the vacuum channels to the vacuum nozzles.   
     
     
         22 . The air-bearing chuck of  claim 20 , wherein the pressure manifold layer comprises a plurality of comprises a plurality of pressure channels; and
 wherein the top chuck layer comprises a plurality of pressure through holes connecting the pressure channels to the pressure nozzles.   
     
     
         23 . The air-bearing chuck of  claim 20 , further comprising one or more openings at the bottom of the air-bearing chuck for connecting the plurality of pressure channels to one or more pressure fittings. 
     
     
         24 . The air-bearing chuck of  claim 20 , wherein the plurality of vacuum through holes are connected to a vacuum outlet. 
     
     
         25 . The air-bearing chuck of  claim 24 , wherein the vacuum outlet is at a bottom of the stacked layers. 
     
     
         26 . The air-bearing chuck of  claim 20 , wherein the plurality of pressure through holes are connected to a pressure outlet. 
     
     
         27 . The air-bearing chuck of  claim 26 , wherein the pressure outlet is at a bottom of the stacked layers. 
     
     
         28 . The air-bearing chuck of  claim 20 , wherein a bottom surface of the stacked layers comprises one or more threaded holes for fastening the vacuum manifold layer, the pressure manifold layer; and the top chuck layer together. 
     
     
         29 . The air-bearing chuck of  claim 20 , wherein the stacked layers further comprises a back cover plate. 
     
     
         30 . The air-bearing chuck of  claim 11 , wherein the alternating vacuum nozzles and pressure nozzles are spaced at between 5 mm-25 mm radially and tangentially.