US Patent 10020220 Wafer positioning pedestal for semiconductor processing

An assembly used in a process chamber for depositing a film on a wafer and including a pedestal extending from a central axis. An actuator is configured for controlling movement of the pedestal. A central shaft extends between the actuator and pedestal, the central shaft configured to move the pedestal along the central axis. A lift pad is configured to rest upon the pedestal and having a pad top surface configured to support a wafer placed thereon. A pad shaft extends between the actuator and the lift pad and controls movement of the lift pad. The pad shaft is positioned within the central shaft and is configured to separate the lift pad from the pedestal top surface by a process rotation displacement when the pedestal is in an upwards position. The pad shaft is configured to rotate relative to the pedestal top surface between first and second angular orientations.