Electrostatic chuck bonded to base with a bond layer and method

• US 6,490,146 B2
• Filed: 08/13/2001
• Issued: 12/03/2002
• Est. Priority Date: 05/07/1999
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Wang, You, Kumar, Ananda H., Kholodenko, Arnold, Grimard, Dennis S., Kats, Semyon L., Bedi, Surinder S., Shamouilian, Shamouil, Narendrnath, Kadthala R., Cheng, Wing L., Veytser, Alexander M.
• Primary Examiner(s): Sircus, Brian
• Assistant Examiner(s): POLK, SHARON A
• Application Number:
  US09/929,806
• Publication Number:
  US 20020075624A1
• Time in Patent Office: 477 Days
• Field of Search: 361/234, 361/115, 361/103, 279/128, 438/16
• US Class Current: 361/234
• CPC Class Codes: C04B 2237/121 based on aluminium
• CPC Class Codes: C04B 2237/122 based on refractory metals
• CPC Class Codes: C04B 2237/123 based on iron group metals, e.g. steel
• CPC Class Codes: C04B 2237/124 based on copper
• CPC Class Codes: C04B 2237/341 Silica or silicates
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 2237/348 Zirconia, hafnia, zirconates or hafnates
• CPC Class Codes: C04B 2237/36 Non-oxidic
• CPC Class Codes: C04B 2237/365 Silicon carbide
• CPC Class Codes: C04B 2237/366 Aluminium nitride
• CPC Class Codes: C04B 2237/368 Silicon nitride
• CPC Class Codes: C04B 2237/401 Cermets
• CPC Class Codes: C04B 2237/402 Aluminium
• CPC Class Codes: C04B 2237/403 Refractory metals
• CPC Class Codes: C04B 2237/406 Iron, e.g. steel
• CPC Class Codes: C04B 2237/407 Copper
• CPC Class Codes: C04B 2237/61 Joining two substrates of which at least one is porous by infiltrating the porous substrate with a liquid, such as a molten metal, causing bonding of the two substrates, e.g. joining two porous carbon substrates by infiltrating with molten silicon
• CPC Class Codes: C04B 2237/62 Forming laminates or joined articles comprising holes, channels or other types of openings
• CPC Class Codes: C04B 2237/64 Forming laminates or joined articles comprising grooves or cuts
• CPC Class Codes: C04B 2237/74 Forming laminates or joined articles comprising at least two different interlayers separated by a substrate
• CPC Class Codes: C04B 37/006 : consisting of metals or metal salts
• CPC Class Codes: C04B 37/021 : in a direct manner, e.g. direct copper bonding [DCB]
• CPC Class Codes: C04B 37/026 : consisting of metals or metal salts
• CPC Class Codes: H01L 21/6831 : using electrostatic chucks
• CPC Class Codes: H01L 21/6833 : Details of electrostatic chucks

Abstract

An electrostatic chuck for holding a substrate has an electrostatic member having a dielectric covering an electrode that is chargeable to electrostatically hold the substrate. The bond layer has a metal layer that is infiltrated or brazed between the electrostatic member and the base. The base may be a composite of a ceramic and metal, the composite having a coefficient of thermal expansion within about ±30% of a coefficient of thermal expansion of the electrostatic member. The base may also have a heater.

Claims

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

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

a base comprising a porous ceramic having a pore volume of from about 20 to about 80 volume %, the base bonded to the electrostatic member by a bond layer, the bond layer comprising a metal that is infiltrated into the porous ceramic, and the base further comprising a heater capable of raising the temperature of a substrate held on the electrostatic member by at least about 100°

C.

2. An electrostatic chuck according to claim 1 wherein the heater comprises a resistive heating element.

3. An electrostatic chuck according to claim 1 wherein the base comprises a composite of a ceramic and metal, the composite having a coefficient of thermal expansion within about ±

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

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

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

(b) forming a base comprising a porous ceramic having a pore volume of from about 20 to about 80 volume %, and a heater capable of raising the temperature of a substrate held on the electrostatic member by at least about 100°

C.; and

(c) bonding the base to the electrostatic member by a bond layer comprising a metal that is infiltrated into the porous ceramic.

5. A method according to claim 4 wherein (c) comprises infiltrating a molten metal into an interface between the electrostatic member and the base.

6. A method according to claim 5 comprising cooling the base and electrostatic member at a cooling rate of from about 10 to about 100°

C./hr.

7. A method according to claim 4 wherein (c) comprises placing a brazing material between the electrostatic member and base and heating the brazing material to a temperature of less than about 600°

C. to form the bond layer.

8. A method according to claim 4 further comprising embedding a heater comprising a resistive heating element in the base.

9. A method according to claim 4 wherein the metal also forms the bond layer.

10. A method according to claim 4 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.

11. A method according to claim 4 comprising infiltrating the porous ceramic with a metal comprising aluminum, copper, iron, molybdenum, titanium, tungsten or alloys thereof.

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

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

a base bonded to the electrostatic member by a bond layer, the base comprising a composite of a ceramic and metal, the composite comprising a coefficient of thermal expansion within about ±

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

13. An electrostatic chuck according to claim 12 wherein the bond layer comprises a metal.

14. An electrostatic chuck according to claim 12 wherein the composite comprises porous ceramic infiltrated with an metal.

15. An electrostatic chuck according to claim 14 wherein the bond layer comprises the same metal as the infiltrated metal.

16. An electrostatic chuck according to claim 12 wherein the base comprises a heater capable of raising the temperature of a substrate held on the electrostatic member by at least about 100°

C.

17. An electrostatic chuck according to claim 16 wherein the heater comprises a resistive heating element.

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

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

(b) forming a base comprising a composite of a ceramic and metal, the composite comprising a coefficient of thermal expansion within about ±

30% of a coefficient of thermal expansion of the electrostatic member; and

(c) bonding the base to the electrostatic member by a bond layer.

19. A method according to claim 18 wherein (c) comprises infiltrating a molten metal into an interface between the electrostatic member and the base.

20. A method according to claim 19 comprising cooling the base and electrostatic member at a cooling rate of from about 10 to about 100°

C./hr.

21. A method according to claim 18 wherein (c) comprises placing a brazing material between the electrostatic member and base and heating the brazing material to a temperature of less than about 600°

C. to form the bond layer.

22. A method according to claim 18 wherein the bond layer comprises a metal.

23. A method according to claim 18 wherein the base further comprises a heater capable of raising the temperature of a substrate held on the electrostatic member by at least about 100°

C.

24. A method according to claim 23 comprising embedding a heater comprising a resistive heating element in the base.

25. A method according to claim 18 comprising forming the base by infiltrating a metal into porous ceramic.

26. A method according to claim 25 wherein the metal also forms the bond layer.

27. A method according to claim 25 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.

28. A method according to claim 25 comprising infiltrating the porous ceramic with a metal comprising aluminum, copper, iron, molybdenum, titanium, tungsten or alloys thereof.