| CPC H01L 21/6833 (2013.01) [H01L 21/67063 (2013.01); H01L 21/67103 (2013.01)] | 18 Claims |
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1. An electrostatic chuck comprising:
a fixing plate on which a wafer is fixed;
a disc shaped electrostatic plate, made of an electrically conductive material, located under the fixing plate and configured to generate an electrostatic force to fix the wafer on the fixing plate;
a plurality of heating elements located under the electrostatic plate, wherein the plurality of heating elements are separated to locally control a temperature of the electrostatic plate; and
a cooling plate located under the plurality of separated heating elements and configured to emit heat transferred by the plurality of separated heating elements,
wherein the electrostatic plate comprises a plurality of heat blocking walls, which are embedded in the electrostatic plate, and configured to locally distribute, on the electrostatic plate, the heat transferred from the plurality of separated heating elements, and
wherein the plurality of heat blocking walls include
a first set of heat blocking walls arranged in a radial direction and formed in a concentrical shape surrounding the center of the electrostatic plate, the first set of heat blocking walls configured to suppress, in an azimuthal direction, a diffusion of heat transferred from the plurality of heating elements to the electrostatic plate, and
a second set of heat blocking walls arranged as concentric walls extending in a continuous circular shape and spaced apart from the first set of heat blocking walls, the second set of heat blocking walls configured to suppress, in a radial direction, a diffusion of heat transferred from the plurality of heating elements to the electrostatic plate,
wherein a first subset of the first set of the heat blocking walls are arranged within the perimeter of the second set of heat blocking walls and a second subset of the first set of the heat blocking walls are arranged outside the perimeter of the second set of heat blocking walls.
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