Electrostatic chuck including clamp electrode assembly forming portion of Faraday cage for RF delivery and associated methods

Patent metadata

Field	Value
Publication number	US-10892179-B2
Application number	US-201715690184-A
Country	US
Kind code	B2
Filing date	Aug 29, 2017
Priority date	Nov 8, 2016
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

A ceramic layer is attached to a top surface of a base plate using a bond layer. The ceramic layer has a top surface configured to support a substrate. A clamp electrode assembly is positioned within an upper region of the ceramic layer. The clamp electrode assembly serves to clamp the substrate to the top surface of the ceramic layer and functions as a primary radiofrequency (RF) power delivery electrode. A plurality of RF power delivery connection modules is distributed in a substantially uniform manner about a perimeter of the ceramic layer. Each of the RF power delivery connection modules is configured to form an electrical connection from the base plate to the clamp electrode assembly at its respective location.

First claim

What is claimed is:

1. An electrostatic chuck, comprising:
a base plate formed of an electrically conductive material;
a ceramic layer attached to a top surface of the base plate using a bond layer disposed between the base plate and the ceramic layer, the ceramic layer having a top surface including an area configured to support a substrate;
a clamp electrode assembly positioned within the ceramic layer in an orientation substantially parallel to the top surface of the ceramic layer and at an upper location within the ceramic layer such that a region of the ceramic layer between the clamp electrode assembly and the top surface of the ceramic layer is substantially free of other electrically conductive material, wherein the clamp electrode assembly is configured to extend horizontally through the ceramic layer to at least span an area underlying the area of the top surface of the ceramic layer that is configured to support the substrate; and
a plurality of RF power delivery connection modules distributed in a substantially uniform manner about a perimeter of the ceramic layer, each of the plurality of RF power delivery connection modules configured to form an electrical connection from the base plate to the clamp electrode assembly at its respective location so as to form an RF power transmission path from the base plate to the clamp electrode assembly at its respective location, wherein the base plate, the plurality of RF power delivery connection modules, and the clamp electrode assembly together form a Faraday cage to direct RF power transmission around an internal volume of the electrostatic chuck, and
wherein each of the plurality of RF power delivery connection modules includes a first electrical connection extending from the base plate to an exposed embedded conductive segment within the ceramic layer, wherein a portion of the exposed embedded conductive segment is exposed at a bottom of the ceramic layer, and wherein each of the plurality of RF power delivery connection modules includes a second electrical connection extending from the exposed embedded conductive segment through the ceramic layer to the clamp electrode assembly.

2. The electrostatic chuck as recited in claim 1 , wherein the first electrical connection includes an electrically conductive pin in compression against the exposed portion of the exposed embedded conductive segment, wherein the electrically conductive pin is electrically connected to the base plate to enable transmission of RF signals from the base plate to the electrically conductive pin.

3. The electrostatic chuck as recited in claim 2 , wherein the electrically conductive pin is configured to transmit up to 30 amperes of electrical current.

4. The electrostatic chuck as recited in claim 1 , wherein the second electrical connection includes one or more interior embedded conductive segments within the ceramic layer, wherein each of the one or more interior embedded conductive segments is oriented substantially parallel to the top surface of the ceramic layer, and wherein the second electrical connection includes one or more vertical conductive structures positioned to electrically connect the one or more interior embedded conductive segments to each other and to the exposed embedded conductive segment and to the clamp electrode assembly.

5. The electrostatic chuck as recited in claim 4 , wherein at least one of the vertical conductive structures extends through the ceramic layer between the exposed embedded conductive segment and a lowest one of the interior embedded conductive segments, and wherein at least one of the vertical conductive structures extends through the ceramic layer between a highest one of the interior embedded conductive segments and the clamp electrode assembly, and wherein at least one of the vertical conductive structures extends through the ceramic layer between each vertically neighboring set of two of the interior embedded conductive segments when present.

6. The electrostatic chuck as recited in claim 4 , wherein at least four of the vertical conductive structures extends through the ceramic layer between the exposed embedded conductive segment and a lowest one of the interior embedded conductive segments, and wherein at least four of the vertical conductive structures extends through the ceramic layer between a highest one of the interior embedded conductive segments and the clamp electrode assembly, and wherein at least four of the vertical conductive structures extends through the ceramic layer between each vertically neighboring set of two of the interior embedded conductive segments when present.

7. The electrostatic chuck as recited in claim 1 , wherein the plurality of RF power delivery connection modules includes eight RF power delivery connection modules positioned near a periphery of the ceramic layer, with each of the eight RF power delivery connection modules separated from each adjacent one of the eight RF power delivery connection modules by an angle of about 45 degrees as measured about a centerline of the ceramic layer extending perpendicular to the top surface of the ceramic layer.

8. The electrostatic chuck as recited in claim 1 , wherein the clamp electrode assembly is formed as a single electrode configured to operate in a monopolar mode.

9. The electrostatic chuck as recited in claim 1 , wherein the clamp electrode assembly is formed as two electrodes configured to operate in a bipolar mode.

10. The electrostatic chuck as recited in claim 1 , further comprising:
a perimeter RF power delivery electrode formed within the ceramic layer at a vertical location within the ceramic layer below the clamp electrode assembly, the perimeter RF power delivery electrode having an annular shape defined by a top surface, a bottom surface, an inner edge, and an outer edge, the top and bottom surfaces of the perimeter RF power delivery electrode oriented substantially parallel to the top surface of the ceramic layer, the inner edge of the perimeter RF power delivery electrode positioned radially closer to a centerline of the ceramic layer than an outer edge of the primary RF power delivery electrode, wherein the centerline of the ceramic layer extends perpendicular to the top surface of the ceramic layer, and wherein the outer edge of the perimeter RF power delivery electrode is positioned farther from the centerline of the ceramic layer than the outer edge of the clamp electrode assembly.

11. The electrostatic chuck as recited in claim 10 , wherein each of the plurality of RF power delivery connection modules includes a first electrical connection extending between the base plate and an exposed embedded conductive segment within the ceramic layer, wherein a portion of the exposed embedded conductive segment is exposed at a bottom of the ceramic layer, and
wherein each of the plurality of RF power delivery connection modules includes a second electrical connection extending from the exposed embedded conductive segment through the ceramic layer to the clamp electrode assembly, wherein the second electrical connection includes a lower electrical connection extending through the ceramic layer from the exposed embedded conductive segment to the perimeter RF power delivery electrode and an upper electrical connection extending through the ceramic layer from the perimeter RF power delivery electrode to the clamp electrode assembly.

12. The electrostatic chuck as recited in claim 11 , wherein the ceramic layer includes a central region and a peripheral region, the central region including the area configured to support the substrate, the peripheral region configured to circumscribe the central region, the ceramic layer having a bottom

Assignees

• Lam Res Corp

Inventors

• Benjamin Neil Martin Paul
• Povolny Henry
• Ricci Anthony J

Classifications

• H10P72/722 Primary

  Details of electrostatic chucks · CPC title

• H10P72/72 Primary

  using electrostatic chucks · CPC title

• H02N13/00

  Clutches or holding devices using electrostatic attraction, e.g. using Johnson-Rahbek effect · CPC title

• H01J37/32174

  Circuits specially adapted for controlling the RF discharge · CPC title

• B23Q3/15

  Devices for holding work using magnetic or electric force acting directly on the work · CPC title