Electrostatic chuck having gas cavity and method

• US 6,310,755 B1
• Filed: 05/07/1999
• Issued: 10/30/2001
• Est. Priority Date: 05/07/1999
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Grimard, Dennis S., Wang, You, Kumar, Ananda H., Kholodenko, Arnold, Kats, Semyon L., Bedi, Surinder S., 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:
  US09/307,215
• Time in Patent Office: 907 Days
• Field of Search: 361/234, 361/233, 361/115, 279/128
• US Class Current: 361/234
• CPC Class Codes: C04B 2235/402 Aluminium
• CPC Class Codes: C04B 2235/5248 Carbon, e.g. graphite
• CPC Class Codes: C04B 2235/616 Liquid infiltration of green bodies or pre-forms
• CPC Class Codes: C04B 2235/96 Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 2235/9607 Thermal properties, e.g. thermal expansion coefficient
• CPC Class Codes: C04B 2237/121 based on aluminium
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 2237/365 Silicon carbide
• CPC Class Codes: C04B 2237/366 Aluminium nitride
• CPC Class Codes: C04B 2237/405 Iron metal group, e.g. Co or Ni
• CPC Class Codes: C04B 2237/60 Forming at the joining interface or in the joining layer specific reaction phases or zones, e.g. diffusion of reactive species from the interlayer to the substrate or from a substrate to the joining interface, carbide forming at the joining interface
• CPC Class Codes: C04B 35/185 Mullite 3Al2O3-2SiO2
• CPC Class Codes: C04B 35/565 based on silicon carbide
• CPC Class Codes: C04B 35/80 Fibres, filaments, whiskers, platelets, or the like
• CPC Class Codes: C04B 37/006 consisting of metals or metal salts
• CPC Class Codes: C04B 37/026 consisting of metals or metal salts
• CPC Class Codes: C04B 38/00 Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof treating slag with gases or gas generating material C04B5/06 ; expanded graphite C04B35/536
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4523 applied from the molten state vitreous materials C04B41/5022; Thermal spraying, e.g. plasma spraying
• CPC Class Codes: C04B 41/5155 Aluminium
• CPC Class Codes: C04B 41/88 : Metals
• CPC Class Codes: C22C 2204/00 : End product comprising different layers, coatings or parts of cermet
• CPC Class Codes: C22C 29/00 : Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides C22C26/00 takes precedence
• CPC Class Codes: H01L 21/67109 : mainly by convection
• CPC Class Codes: H01L 21/6831 : using electrostatic chucks
• CPC Class Codes: H01L 21/6833 : Details of electrostatic chucks

Abstract

An electrostatic chuck 55 has an electrostatic member 100 including a dielectric 115 having a surface 120 adapted to receive the substrate 30. The dielectric 115 covers an electrode 105 that is chargeable to electrostatically hold the substrate 30. A support 190 below the electrostatic member 100 has a cavity 300 adapted to hold a gas to serve as a thermal insulator to regulate the flow of heat from the electrostatic chuck 55 to a surface 120 of the chamber 25. The cavity 300 has a cross-sectional profile that is shaped to provide a predetermined temperature profile across the substrate 30.

Claims

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

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

(b) a support below the electrostatic member, the support comprising a coefficient of thermal expansion within about ±

30% of a coefficient of thermal expansion of the electrostatic member, and the support comprising a cavity adapted to hold gas.

2. An electrostatic chuck according to claim 1 wherein the cavity is adapted to maintain a temperature differential of at least about 100°

C. between the electrostatic member and a surface of the chamber.

3. An electrostatic chuck according to claim 1 wherein the cavity comprises a cross-sectional profile that is shaped to provide a predetermined temperature profile across the substrate.

4. An electrostatic chuck according to claim 1 further comprising a heater between the electrostatic member and the cavity.

5. An electrostatic chuck according to claim 1 wherein the support comprises one or more of aluminum oxide, aluminum nitride, boron carbide, carbon, cordierite, mullite, silicon carbide, silicon nitride, silicon dioxide and zirconium oxide.

6. An electrostatic chuck according to claim 1 wherein the support comprises one or more of aluminum, copper, molybdenum, titanium, tungsten, zirconium or mixtures thereof.

7. An electrostatic chuck according to claim 1 further comprising a base between the electrostatic member and the support, the base comprising a composite of a plurality of materials.

8. An electrostatic chuck according to claim 7 wherein the base comprises silicon carbide and aluminum.

9. An electrostatic chuck according to claim 1 wherein the support comprises a coefficient of thermal expansion of from about 2 to about 27 ppm/°

C.

10. An electrostatic chuck according to claim 1 wherein the support comprises zirconium.

11. A method of processing a substrate in a chamber, the method comprising the steps of:

(a) placing the substrate on an electrostatic member in the chamber;

(b) supporting the electrostatic member on a support having a coefficient of thermal expansion within about ±

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

(c) providing a gas in a cavity in the support; and

(d) providing an energized process gas in the chamber to process the substrate.

12. A method according to claim 11 wherein step (c) comprises the initial step of shaping the cavity to provide a temperature differential of at least about 100°

C. between the electrostatic member and a surface of the chamber.

13. A method according to claim 11 wherein the pressure of gas in the cavity is regulated to maintain substantially uniform temperatures across the substrate.

14. A method according to claim 13 wherein the pressure of the gas is less than about 50 mTorr.

15. A method according to claim 13 wherein the pressure of the gas is from about 2 to about 50 mtorr.

16. A method according to claim 11 comprising heating the substrate by powering a heater below the electrostatic member.

17. A method according to claim 11 wherein the support comprises a coefficient of thermal expansion of from about 2 to about 27 ppm/°

C.

18. An electrostatic chuck for holding a substrate in a chamber, the electrostatic chuck comprising:

(a) an electrostatic member comprising a dielectric having a surface capable of receiving the substrate, the dielectric covering an electrode that is chargeable to electrostatically hold the substrate;

(b) a heater below the electrostatic member, the heater comprising a resistive heating element having a resistance sufficiently high to raise the temperature of the substrate by at least about 100°

C.; and

(c) a support below the electrostatic member, the support comprising a coefficient of thermal expansion within about ±

30% of a coefficient of thermal expansion of the electrostatic member, and the support comprising a cavity that is shaped and sized to hold a gas to provide a temperature drop of at least about 100°

C. between the electrostatic member and a surface of the chamber.

19. An electrostatic chuck according to claim 18 wherein the cavity is shaped to provide a predetermined temperature profile across the substrate.

20. An electrostatic chuck according to claim 18 wherein the cavity comprises a channel having a gas inlet and a gas outlet.

21. An electrostatic chuck according to claim 18 wherein the support comprises aluminum, copper, molybdenum, titanium, tungsten, zirconium or mixtures thereof.

22. An electrostatic chuck according to claim 18 wherein the support comprises zirconium.

23. An electrostatic chuck according to claim 18 wherein the support comprises a coefficient of thermal expansion of from about 2 to about 27 ppm/°

C.

24. An electrostatic chuck for holding a substrate in a chamber, the electrostatic chuck comprising:

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

(b) a support below the electrostatic member, the support comprising zirconium, and the support comprising a cavity adapted to hold gas.

25. An electrostatic chuck according to claim 24 wherein the cavity is adapted to hold gas to provide a predetermined temperature profile across the substrate.

26. An electrostatic chuck according to claim 24 wherein the cavity is adapted to maintain a temperature differential of at least about 100°

C. between the electrostatic member and a surface of the chamber.

27. An electrostatic chuck according to claim 24 further comprising a heater between the electrostatic member and the cavity.

28. An electrostatic chuck according to claim 24 wherein the support comprises a coefficient of thermal expansion within about ±

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

29. An electrostatic chuck according to claim 24 wherein the support comprises a coefficient of thermal expansion of from about 2 to about 27 ppm/°

C.

30. An electrostatic chuck according to claim 26 wherein the support comprises one or more of aluminum oxide, aluminum nitride, boron carbide, carbon, cordierite, mullite, silicon carbide, silicon nitride, silicon dioxide and zirconium oxide.

31. An electrostatic chuck according to claim 24 wherein the support further comprises one or more of aluminum, copper, molybdenum, titanium, tungsten, or mixtures thereof.

32. An electrostatic chuck according to claim 24 further comprising a base between the electrostatic member and the support, the base comprising a composite of a plurality of materials.

33. An electrostatic chuck according to claim 32 wherein the base comprises silicon carbide and aluminum.

34. An electrostatic chuck for holding a substrate in a chamber, the electrostatic chuck comprising:

(a) an electrostatic member comprising a dielectric having a surface capable of receiving the substrate, the dielectric covering an electrode that is chargeable to electrostatically hold the substrate;

(b) a heater below the electrostatic member, the heater comprising a resistive heating element having a resistance sufficiently high to raise the temperature of the substrate by at least about 100°

C.; and

(c) a support below the electrostatic member, the support comprising zirconium, and the support comprising a cavity that is shaped and sized to hold a gas to provide a temperature drop of at least about 100°

C. between the electrostatic member and a surface of the chamber.

35. An electrostatic chuck according to claim 34 wherein the cavity is shaped to provide a predetermined temperature profile across the substrate.

36. An electrostatic chuck according to claim 34 wherein the support comprises a coefficient of thermal expansion within about ±

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

37. An electrostatic chuck according to claim 34 wherein the support comprises a coefficient of thermal expansion of from about 2 to about 27 ppm/°

C.

38. An electrostatic chuck according to claim 34 wherein the support further comprises aluminum, copper, molybdenum, titanium, tungsten, or mixtures thereof.