Annulus clamping and backside gas cooled electrostatic chuck
First Claim
1. An electrostatic clamp for clamping a workpiece, the electrostatic clamp comprising:
- a clamping plate, comprising;
an annulus comprising a first layer having a first surface associated therewith, wherein the first surface is configured to contact a peripheral region of a surface of the workpiece;
a central disk comprising a second layer having a second surface, wherein the annulus generally encircles the central disk, and wherein the second surface is generally recessed from the first surface, therein generally defining a gap between the second surface and the surface of the workpiece; and
one or more backside gas delivery apertures in fluid communication with a gas supply and positioned proximate to an interface between the annulus and the central disk;
a first electrode associated with the annulus, wherein the first electrode is electrically connected to a first voltage potential; and
a second electrode associated with the central disk, wherein the second electrode is electrically connected to a second voltage potential, and wherein the first electrode and second electrode are electrically isolated from one another..
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Accused Products
Abstract
An electrostatic clamp (ESC), system, and method for clamping a workpiece is provided. A clamping plate of the ESC has central disk and an annulus encircling the central disk, wherein the central disk is recessed from the annulus by a gap distance, therein defining a volume. Backside gas delivery apertures are positioned proximate to an interface between the annulus and the central disk. A first voltage to a first electrode of the annulus clamps a peripheral region of the workpiece to a first layer. A second voltage to a second electrode of the central disk generally compensates for a pressure of a backside gas within the volume. The ESC can be formed of J-R- or Coulombic-type materials. A cooling plate associated with the clamping plate further provides cooling by one or more cooling channels configured to route a cooling fluid therethrough.
64 Citations
25 Claims
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1. An electrostatic clamp for clamping a workpiece, the electrostatic clamp comprising:
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a clamping plate, comprising; an annulus comprising a first layer having a first surface associated therewith, wherein the first surface is configured to contact a peripheral region of a surface of the workpiece; a central disk comprising a second layer having a second surface, wherein the annulus generally encircles the central disk, and wherein the second surface is generally recessed from the first surface, therein generally defining a gap between the second surface and the surface of the workpiece; and one or more backside gas delivery apertures in fluid communication with a gas supply and positioned proximate to an interface between the annulus and the central disk; a first electrode associated with the annulus, wherein the first electrode is electrically connected to a first voltage potential; and a second electrode associated with the central disk, wherein the second electrode is electrically connected to a second voltage potential, and wherein the first electrode and second electrode are electrically isolated from one another.. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method for clamping a workpiece, the method comprising:
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providing a clamping plate, wherein the clamping plate comprises an annulus having a first electrode and a first layer associated therewith, a central disk having a second electrode and a second layer associated therewith, wherein the central disk is generally recessed from the annulus, and wherein the clamping plate further comprises one or more backside gas delivery apertures positioned proximate to an interface between the annulus and the central disk; placing the workpiece on the clamping plate, wherein a peripheral region of the workpiece contacts the first layer, and wherein a volume is generally defined by a gap distance between the second layer and a central region of the workpiece; applying a first voltage potential to the first electrode, therein generally attracting the peripheral region of the workpiece to the first layer with a first force; providing a backside gas at a backside gas pressure to the one or more backside gas delivery apertures, wherein the backside gas pressure generally pressurizes the volume between the second layer and the central region of the workpiece; applying a second voltage potential to the second electrode, therein generally attracting the central region of the workpiece to the second layer with a second force; and controlling the first voltage potential and second voltage potential, wherein the first voltage potential generally clamps the workpiece to the clamping plate via the first force, and wherein the second voltage potential generally compensates for the backside gas pressure via the second force, therein generally controlling the gap distance. - View Dependent Claims (21, 22, 23, 24, 25)
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Specification