During ADP processing, a wafer holder uses multiple gas vortices to suspend wafers without touching them. This protects the front side of the wafer from etching gas with positive airflow, leaving the front side literally untouched. This is particularly useful for thinning wafers after they have been bumped. This principle is also used for internal wafer handling. The wafer loading and unloading robot has an end effector that uses multiple gas vortices from above, and wafer shuttles use the effect from beneath. Wafers are continually held flat, despite the bow that comes from thinning. Wafers are picked out of cassettes from the top to avoid damaging wafers with unpredictable sag.