US Patent 7566370 Wafer clamping apparatus and method for operating the same

A wafer clamping apparatus is provided to secure a wafer within a chamber during wafer processing. The wafer clamping apparatus creates a pressure differential between a top surface and a bottom surface of the wafer. The pressure differential serves to pull the wafer toward a wafer support structure in contact with the wafer bottom surface, whereby the wafer is secured and maintained in an immobile state. The wafer clamping apparatus also includes options for controlling the pressure differential between the top and bottom surfaces of the wafer. The wafer clamping apparatus is implemented without requiring contact with the wafer top surface and with minimal increase in chamber design complexity.