Patent ID: 6032715
Filing Date: 2000-03-07
Classification: B25B,Y10T

Abstract:
A wafer substrate holder comprising:a cylindrical base having a top surface and a generally cylindrical engagement recess extending inwardly from an opening in the top surface to an end wall, said base further including a bottom surface opposite the top surface including a central cylindrical projection, said central cylindrical projection including a central bore extending from a vent opening in said end wall to a rear opening in an end surface of the central cylindrical projection, a chuck member flush mounted with respect to the top surface in said engagement recess, said chuck member comprising a porous material and having a wafer contact surface defined by a plurality of alternating concentric protrusions and grooves extending radially outwardly from a central portion of the wafer contact surface to a circumference of the wafer contact surface, a pair of diametrical evacuation channels disposed orthogonally with respect to each other and intersecting at a central hub adjacent the central portion of the wafer contact surface, the evacuation channels intersecting the plurality of grooves, a plurality of openings provided between each groove and the evacuation channels at points where they intersect; and a connector connecting the cylindrical projection to a vacuum source, said grooves in said wafer contact surface being configured and disposed so that upon application of vacuum suction through the connector to the central hub and evacuation channels, substantially all air born particles falling on said wafer contact surface are drawn into the grooves and away from said protrusions making contact with a wafer supported on the wafer contact surface.