Method and system for loading substrate supports into a substrate holder

Wafer supports are provided that have a diameter smaller than the diameter of the wafer that they are to support in a wafer boat. The perimeter of the wafer support is preferably continuous, extending completely around in a 360° span, and is sized to fit between the protrusions supporting a particular wafer in a wafer cassette. To load the wafer boat, an end effector removes the wafer support from a wafer boat and moves the wafer support into a wafer cassette, where the end effector moves upward to seat a wafer upon the wafer support. The wafer and wafer support are then transported to the wafer boat and the wafer support and the wafer are lowered onto a wafer slot surface in a wafer slot in the wafer boat, to transfer the wafer support and wafer from the end effector to the wafer boat.