Electrostatic chunks
AssigneeNGK Insulators, Ltd.
InventorsHideyoshi Tsuruta, Kazuaki Yamaguchi
Life of this patent
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Abstract
An electrostatic chuck includes a chuck body, an insulating layer formed on a surface of the chuck body and having an installation surface on which a wafer is to be installed, an inner electrode installed inside the insulating-layer, and projections projecting from the installation surface and having contact surfaces to which the wafer is to contact. A back side gas is flown into a space defined by the installation surface, the projections and the wafer, heat is supplied to the wafer, and heat of the wafer is conducted to the electrostatic chuck through the projections and the back side gas. The total area of the contact surfaces of the projections is not more than 1% of the area of the inner electrode, and the height of the projections are not less than 1 μm and not more than 10 μm.
Claims20
An electrostatic chuck comprising a chuck body, an insulating layer formed on a surface of the said chuck body and having an installation surface on which a wafer is to be installed, an inner electrode installed inside said insulating layer, and projections projecting from said installation surface and having contact surfaces to which the wafer is to contact:
- wherein a back side gas is flown into a space defined by said installation surface, said projections and said wafer, heat is supplied to the wafer, and heat of the wafer is conducted to said electrostatic chuck through said projections and the back side gas;
- and
- wherein the total area of said contact surfaces of said projections is not more than 1% of the area of an upper surface of said inner electrode, and said height of said projections is in a range of 1 μm to 10 μm.
Dependencies are inferred from the claim text.