Electrostatic chuck

An electrostatic chuck, comprising:

• a base plate;
• and
• a ceramic dielectric substrate having a substantially circular planar configuration, being provided on the base plate, and having a first major surface exposed externally,
• the first major surface including at least a first region, and a second region adjacent to the first region,
• the first region having a plurality of first grooves, at least one first gas introduction hole, and at least one second groove provided in the first region, the at least one first gas introduction hole being connected to at least one of the plurality of first grooves, the at least one second groove extending in a direction crossing the plurality of first grooves,
• the plurality of first grooves having substantially circular planar configurations and being provided concentrically,
• the second groove being connected to at least two of the first grooves,
• wherein:
• at least a portion of the first gas introduction hole overlaps at least one of the first groove or the second groove at a portion where the first groove and the second groove are connected,
• the first region has a first boundary groove at an edge portion thereof proximate the second region,
• the second region has a second boundary groove at an edge portion thereof proximate the first region, and
• the first and second boundary grooves are spaced closer together than other, adjacent grooves of the plurality of first grooves.

An electrostatic chuck, comprising:

• a base plate;
• and
• a ceramic dielectric substrate having a substantially circular planar configuration, being provided on the base plate, the ceramic dielectric substrate having a first major surface exposed externally, and having a plurality of spaced-apart raised dots extending upwardly from the first major surface and configured to support a workpiece thereon at a level above the first major surface,
• the first major surface including at least a first region, and a second region adjacent to the first region,
• the first region having a plurality of first grooves, at least one first gas introduction hole, and at least one second groove provided in the first region, the at least one first gas introduction hole being connected to at least one of the plurality of first grooves, the at least one second groove extending in a direction crossing the plurality of first grooves,
• the plurality of first grooves having substantially circular planar configurations and being provided concentrically,
• the second groove being connected to at least two of the first grooves,
• wherein at least a portion of the first gas introduction hole overlaps at least one of the first groove or the second groove at a portion where the first groove and the second groove are connected, the first region has a first boundary groove at an edge portion thereof proximate the second region, the second region has a second boundary groove at an edge portion thereof proximate the first region, and the first and second boundary grooves are spaced closer together than other, adjacent grooves of the plurality of first grooves.