Electrostatic chuck having heater and method

• US 6,538,872 B1
• Filed: 11/05/2001
• Issued: 03/25/2003
• Est. Priority Date: 11/05/2001
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Bedi, Surinder S., Wang, You, Kumar, Ananda H., Kholodenko, Arnold, Grimard, Dennis S., Kats, Semyon L., Shamouilian, Shamouil, Narendrnath, Kadthala R., Cheng, Wing L., Veytser, Alexander M.
• Primary Examiner(s): Jackson, Stephen W.
• Assistant Examiner(s): POLK, SHARON A
• Application Number:
  US09/307,214
• Time in Patent Office: 505 Days
• Field of Search: 361/234, 361/115, 361/103, 279/128, 438/16
• US Class Current: 361/234
• CPC Class Codes: H01L 21/67103 mainly by conduction
• CPC Class Codes: H01L 21/6833 Details of electrostatic chucks

Abstract

An electrostatic chuck 55 for holding a substrate 30 comprises an electrostatic member 100 made from a dielectric 115 covering an electrode 105 that is chargeable to electrostatically hold the substrate 30. A base 175 that includes a heater 235 is joined to the electrostatic member 100. The base may be made from a composite material, such as a porous ceramic infiltrated with the metal, and may be joined to the electrostatic member by a bond layer.

Claims

1. An electrostatic chuck for holding a substrate, the electrostatic chuck comprising:

(a) an electrostatic member comprising a dielectric covering an electrode that is chargeable to electrostatically hold the substrate; and

(b) a base below the electrostatic member, the base comprising a composite of ceramic and metal, and a heater.

2. An electrostatic chuck according to claim 1 wherein the heater comprises a resistive heating element composed of tungsten, molybdenum, iron, nickel, copper, Inconel or alloys thereof.

3. An electrostatic chuck according to claim 1 wherein the heater comprises a resistance sufficiently high to raise the temperature of a substrate held on the electrostatic member by at least about 100°

C.

4. An electrostatic chuck according to claim 1 wherein the heater is substantially planar.

5. An electrostatic chuck according to claim 1 wherein the composite comprises a coefficient of thermal expansion within about ±

30% of a coefficient of thermal expansion of the electrostatic member.

6. An electrostatic chuck according to claim 1 wherein the composite comprises porous ceramic infiltrated with metal.

7. An electrostatic chuck according to claim 1 wherein the electrostatic member and base comprise separate structures that are joined to one another.

8. An electrostatic chuck according to claim 7 wherein the electrostatic member and base are joined by a bond layer comprising a metal.

9. A method of fabricating an electrostatic chuck for holding a substrate, the method comprising:

(a) forming an electrostatic member comprising a dielectric covering an electrode that is chargeable to electrostatically hold the substrate; and

(b) forming a base comprising a composite of ceramic and metal, a heater, and having a surface that can be joined to the electrostatic member.

10. A method according to claim 9 further comprising joining the electrostatic member to the base.

11. A method according to claim 9 further comprising joining the electrostatic member to the base by a bond layer comprising a metal.

12. A method according to claim 9 wherein (b) comprises forming the base by infiltrating a metal into a porous ceramic.

13. A method according to claim 12 wherein (b) comprises embedding a heater comprising a resistive heating element in the porous ceramic.

14. A method according to claim 12 comprising forming the porous ceramic by sintering one or more of aluminum oxide, aluminum nitride, boron carbide, carbon, cordierite, mullite, silicon carbide, silicon nitride, silicon dioxide and zirconium oxide.

15. A method according to claim 12 wherein (b) comprises infiltrating the porous ceramic with a metal comprising aluminum, copper, iron, molybdenum, titanium, tungsten or alloys thereof.

16. A method according to claim 9 wherein (b) comprises forming a heater comprising a resistance sufficiently high to be able to raise the temperature of a substrate held on the electrostatic member by at least about 100°

C.

17. A method according to claim 9 wherein (b) comprises forming a heater that is substantially planar.

18. A method according to claim 9 wherein the electrostatic member and base comprise separate structures.