Varian/ Applied Materials VIISta PLAD vacuum wafer chuck High Dose Doping

 Varian/ Applied Materials VIISta PLAD vacuum wafer chuck High Dose Doping

This vacuum chuck has a network of small pressure actuated valves within the precision machined Graphite top plate.  These valves allow a vacuum source to draw down a wafer on the very flat graphite substrate. The weight of a single wafer is enough to push down the valve pins and allow vacuum to the chuck.  Also within the chuck surface there are three larger holes for the wafer lift assembly. This makes clearance for a transfer robot to get under the wafer.  That mechanism would be part of the under surface of the chuck.  The main chuck carrier is aluminum. The wafer contact area has been surface ground to a flatness of extreme precision.  This is part of the Applied Materials Ion Implant instrument.