Apparatuses and techniques for cleaning a multi-station semiconductor processing chamber

A substrate movement mechanism for semiconductor processing, the substrate movement mechanism comprising:

• a hub having a center axis and a top surface with a plurality of channels arranged in a radial pattern around the center axis, wherein:
• each channel extends along a pathway that extends in a radial direction from a center region of the hub to an edge of the hub,
• each channel has a cross-sectional area perpendicular to the corresponding pathway, and
• at least one of the channels has a cross-sectional area that is different than a cross-sectional area of another channel and/or that varies along the pathway.

A method of cleaning a multi-station processing chamber having a plurality of processing stations within a chamber interior, a hub located in a center area of the chamber interior, configured to be moveable along a vertical center axis of the hub relative to the chamber, and having a first set of flow redirection features in a first radial region of a top surface of the hub and a second set of flow redirection features in a second radial region of the top surface of the hub which is concentric with the first radial region, and a cleaning chemistry inlet configured to direct a cleaning chemistry from a remote source into the chamber interior and onto the top surface of the hub, wherein one of the first radial region and the second radial region is encircled by the other of the first radial region and the second radial region, the flow redirection features in the first set of flow redirection features each have a first cross-sectional profile in a corresponding plane that is coincident with, and parallel to, the vertical center axis, the flow redirection features in the second set of flow redirection features each have a second cross-sectional profile in a corresponding plane that is coincident with, and parallel to, the vertical center axis, and the method comprising:

• flowing, while the hub is at a first elevational position with respect to the cleaning chemistry inlet, the cleaning chemistry from the remote source through the cleaning chemistry inlet and onto the top surface of the hub, thereby causing the cleaning chemistry to impinge on the flow redirection features in the first set of flow redirection features and be directed along a first outward direction;
• moving the hub from the first elevational position to a second elevational position;
• and
• flowing, while the hub is at the second elevational position with respect to the cleaning chemistry inlet, the cleaning chemistry from the remote source through the cleaning chemistry inlet and onto the top surface of the hub, thereby causing the cleaning chemistry to impinge on the flow redirection features in the second set of flow redirection features and be directed along a second outward direction, in which the first outward direction and the second outward direction are different.