Electrostatic chuck with radiative heating
First Claim
1. A system for holding and heating a workpiece, comprising:
- an electrostatic chuck, having a first surface for supporting said workpiece clamped to said first surface and a second surface opposite said first surface, comprising an insulating layer and a dielectric layer, and wherein an electrically conductive pattern is embedded in a surface of said insulating layer; and
one or more radiative heat sources proximate said second surface of said electrostatic chuck, emitting radiative heat within a predetermined frequency range, wherein said electrostatic chuck is comprised of a material that is optically transparent to at least a portion of said predetermined frequency range,wherein said electrically conductive pattern is a mesh formed of channels, with an electrically conductive material disposed in said channels, said channels spaced apart to provide a sufficiently large open area for said radiative heat to pass through, wherein the channels occupy less than about 20% of an area of said surface of said insulating layer.
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Accused Products
Abstract
An electrostatic chuck is formed using materials that are optically transparent to a range of frequencies, such as infrared radiation. The invention discloses several methods for achieving optical transparency. The chuck electrode can be formed having a mesh pattern designed with a specific open area percentage to provide adequate wafer clamping force while still allowing sufficient levels of infrared radiation to pass through. Alternatively, the chuck electrode can also be made from a transparent conductive film. A workpiece is disposed on one surface of the chuck, and a radiative heat source is positioned on the opposite side of the chuck. A reflector plate may be used to reflect the infrared radiation toward the chuck and the wafer. The spacing of the radiation sources and the shape of the reflector plate may be modified to focus more radiation on a particular portion of the workpiece if desired.
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Citations
16 Claims
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1. A system for holding and heating a workpiece, comprising:
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an electrostatic chuck, having a first surface for supporting said workpiece clamped to said first surface and a second surface opposite said first surface, comprising an insulating layer and a dielectric layer, and wherein an electrically conductive pattern is embedded in a surface of said insulating layer; and one or more radiative heat sources proximate said second surface of said electrostatic chuck, emitting radiative heat within a predetermined frequency range, wherein said electrostatic chuck is comprised of a material that is optically transparent to at least a portion of said predetermined frequency range, wherein said electrically conductive pattern is a mesh formed of channels, with an electrically conductive material disposed in said channels, said channels spaced apart to provide a sufficiently large open area for said radiative heat to pass through, wherein the channels occupy less than about 20% of an area of said surface of said insulating layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An electrostatic chuck, comprising:
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an insulating layer comprising channels in its top surface; an electrically conductive material disposed in said channels, said electrically conductive material forming a mesh electrode; and
adielectric layer deposited on said insulating layer, wherein said insulating layer and said dielectric layer are optically transparent to a predetermined frequency range and wherein said channels are sufficiently thin and spaced apart so as occupy less than about 20% of an area of said surface of said insulating layer. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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Specification