High surface resistivity electrostatic chuck

• US 9,025,305 B2
• Filed: 05/24/2011
• Issued: 05/05/2015
• Est. Priority Date: 05/28/2010
• Status: Active Grant

• Current Assignee: Varian Semiconductor Equipment Associates Incorporated (Applied Materials Incorporated), Entegris Incorporated
• Original Assignee: Varian Semiconductor Equipment Associates Incorporated (Applied Materials Incorporated), Entegris Incorporated
• Inventors: Cooke, Richard A., Stone, Dale K., Stone, Lyudmila, Blake, Julian, Suuronen, David
• Primary Examiner(s): Nguyen, Danny
• Application Number:
  US13/699,279
• Publication Number:
  US 20130070384A1
• Time in Patent Office: 1,442 Days
• Field of Search: 361230-234
• US Class Current: 361/234
• CPC Class Codes: B05D 5/12 to obtain a coating with specific electrical properties
• CPC Class Codes: B23Q 3/152 Rotary devices
• CPC Class Codes: C04B 2237/06 Oxidic interlayers
• CPC Class Codes: C04B 2237/062 based on silica or silicates
• CPC Class Codes: C04B 2237/08 Non-oxidic interlayers
• CPC Class Codes: C04B 2237/083 Carbide interlayers, e.g. silicon carbide interlayers
• CPC Class Codes: C04B 2237/086 Carbon interlayers
• CPC Class Codes: C04B 2237/341 Silica or silicates
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 2237/365 Silicon carbide
• CPC Class Codes: C04B 2237/368 Silicon nitride
• CPC Class Codes: C04B 37/005 consisting of glass or ceramic material
• CPC Class Codes: C04B 37/008 by means of an interlayer consisting of an organic adhesive, e.g. phenol resin or pitch
• CPC Class Codes: C23F 1/00 Etching metallic material by chemical means manufacture of printing surfaces B41C; manufacture of printed circuits H05K
• CPC Class Codes: H01L 21/6833 Details of electrostatic chucks
• CPC Class Codes: H02N 13/00 Clutches or holding devices using electrostatic attraction, e.g. using Johnson-Rahbek effect

Abstract

In accordance with an embodiment of the invention, there is provided an electrostatic chuck. The electrostatic chuck comprises an electrode, and a surface layer activated by a voltage in the electrode to form an electric charge to electrostatically clamp a substrate to the electrostatic chuck, the surface layer including a charge control layer comprising a surface resistivity of greater than about 10¹¹ ohms per square.

Claims

1. An electrostatic chuck comprising:

an electrode; and

a surface layer activated by a voltage in the electrode to form an electric charge to electrostatically clamp a substrate to the electrostatic chuck, the surface layer including;

(i) a dielectric;

(ii) a charge control layer comprising a polymer, and comprising a surface resistivity of from about 1×

10¹² ohms/square to about 1×

10¹⁶ ohms/square, wherein the polymer included in the charge control layer comprises at least one of polyetherimide (PEI) and polyether ether ketone (PEEK); and

(iii) a plurality of polymer protrusions extending to a height above portions of the charge control layer surrounding the plurality of polymer protrusions to support the substrate upon the plurality of polymer protrusions during electrostatic clamping of the substrate.

2. An electrostatic chuck according to claim 1, wherein the charge control layer comprises a surface resistivity of from about 1×

10¹³ ohms/square to about 1×

10¹⁶ ohms/square.

3. An electrostatic chuck according to claim 1, wherein the polymer of which the plurality of polymer protrusions are formed comprises at least one of polyetherimide (PEI), polyimide and polyether ether ketone (PEEK).

4. An electrostatic chuck according to claim 1, wherein the polymer of which the plurality of polymer protrusions are formed comprises polyetherimide (PEI), wherein the charge control layer is formed of polyetherimide (PEI), and wherein the charge control layer comprises a surface resistivity of from about 1×

10¹³ ohms/square to about 1×

10¹⁶ ohms/square.

5. A method of manufacturing an electrostatic chuck, the method comprising:

forming a surface layer in the electrostatic chuck, the surface layer comprising;

(i) a dielectric;

(ii) a charge control layer comprising a polymer, and comprising a surface resistivity of from about 1×

10¹² ohms/square to about 1×

10¹⁶ ohms/square, wherein the polymer included in the charge control layer comprises at least one of polyetherimide (PEI) and polyether ether ketone (PEEK); and

(iii) a plurality of polymer protrusions extending to a height above portions of the charge control layer surrounding the plurality of polymer protrusions to support the substrate upon the plurality of polymer protrusions during electrostatic clamping of the substrate.

6. A method according to claim 5, wherein the charge control layer comprises a surface resistivity of from about 1×

10¹³ ohms/square to about 1×

10¹⁶ ohms/square.

7. A method according to claim 5, wherein the method comprising reducing frequency of wafer sticking in use of the electrostatic chuck without modifying the functioning of the electrostatic chuck, including by not modifying at least one of the power supply, electrode structure, dielectric thickness, mechanical properties and clamping force of the electrostatic chuck.

8. A method according to claim 5, wherein the forming the charge control layer comprises altering the surface resistivity of a surface layer that has already been produced.

9. A method according to claim 8, wherein the altering the surface resistivity comprises treating the surface layer, which has already been produced, using a reactive ion etch process.

10. A method according to claim 9, wherein the altering the surface resistivity comprises performing at least one of a plasma treatment, a chemical treatment and a rehydrogenation treatment of the surface layer that has already been produced.

11. A method according to claim 9, wherein the altering of the surface resistivity produces a surface resistivity after treatment that is within plus or minus 25% of what the surface resistivity would have been prior to treatment.

12. A method according to claim 9, wherein the method comprises, prior to forming the charge control layer:

bonding a dielectric layer of the electrostatic chuck to an insulator layer of the electrostatic chuck;

coating the dielectric layer of the electrostatic chuck with an adhesion coating layer comprising at least one of silicon containing nitride, silicon containing oxide, silicon containing carbide, non-stoichiometric silicon containing nitride, non-stoichiometric silicon containing oxide, non-stoichiometric silicon containing carbide, carbon and a nitride compound of carbon;

bonding the charge control layer comprising the charge control layer polymer to the surface of the electrostatic chuck, the charge control layer polymer comprising at least one of polyetherimide (PEI), polyimide and polyether ether ketone (PEEK);

depositing a photoresist onto the charge control layer;

reactive ion etching the charge control layer to remove portions of the charge control layer that will surround the plurality of polymer protrusions being formed in the charge control layer; and

stripping the photoresist off the electrostatic chuck, thereby revealing the plurality of polymer protrusions being formed of the same charge control layer polymer as the charge control layer.

13. A method of manufacturing an electrostatic chuck, the method comprising:

forming a charge control layer in the electrostatic chuck, the charge control layer comprising at least one of silicon containing oxide, silicon containing carbide, non-stoichiometric silicon containing oxide, non-stoichiometric silicon containing carbide, carbon and a nitride compound of carbon, and comprising a surface resistivity of from about 1×

10¹² ohms/square to about 1×

10¹⁶ ohms/square;

wherein the method comprises reducing frequency of wafer sticking in use of the electrostatic chuck without modifying the functioning of the electrostatic chuck, including by not modifying at least one of the power supply, electrode structure, dielectric thickness, mechanical properties and clamping force of the electrostatic chuck.

14. A method of manufacturing an electrostatic chuck, the method comprising:

forming a charge control layer in the electrostatic chuck, the charge control layer comprising at least one of silicon containing oxide, silicon containing carbide, non-stoichiometric silicon containing oxide, non-stoichiometric silicon containing carbide, carbon and a nitride compound of carbon, and comprising a surface resistivity of from about 1×

10¹² ohms/square to about 1×

10¹⁶ ohms/square;

wherein the forming the charge control layer comprises altering the surface resistivity of a surface layer that has already been produced;

wherein the altering the surface resistivity comprises treating the surface layer, which has already been produced, using a reactive ion etch process; and

wherein the altering of the surface resistivity produces a surface resistivity after treatment that is within plus or minus 25% of what the surface resistivity would have been prior to treatment.