Abstract: A centrifugal semiconductor processing system having a rotor which holds articles for centrifugal processing. The rotor includes a rotor frame with a receiver for holding the wafers or other articles in a spaced array without a wafer carrier to improve fluid access to the wafers. The rotor also has one or more retainers which are pivoted relative to the rotor to controllably urge the wafers into their desired processing positions. The retainers are preferably constructed to provide initial spring biasing with added restraining forces being generated during rotation. The processing system also preferably includes an implement mounted on a robot for loading the rotor, and a vision system to aid in the loading operation.