Wafer chuck assembly

The present disclosure generally relates to chuck technology for supporting semiconductor wafers during processing. In one example, a wafer chuck assembly comprises a chuck hub and a centering hub disposed within the chuck hub. An engagement device is operable between an engaged position and a disengaged position respectively to engage the chuck hub with the centering hub to prevent relative movement therebetween in at least a first direction, or to allow relative movement therebetween. A chuck motor is provided for selectively rotating the chuck hub and/or the centering hub during a wafer processing operation and a wafer centering operation based on an engaged or disengaged position of the engagement device. A plurality of chuck arms is mounted to the chuck hub, each chuck arm extending radially between a proximal end adjacent the chuck hub, and a distal end remote therefrom. Each of a plurality of centering cams is mounted at or towards a distal end of a chuck arm, and movable to engage or release a wafer e