Method and apparatus for controlling temperature of a substrate

• US 20060076108A1
• Filed: 10/07/2004
• Published: 04/13/2006
• Est. Priority Date: 10/07/2004
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Holland, John, Panagopoulos, Theodoros
• Granted Patent: US 7,544,251 B2
• Time in Patent Office: Days
• US Class Current: 156/345.270
• CPC Class Codes: H01L 21/67103 mainly by conduction
• CPC Class Codes: H01L 21/67248 Temperature monitoring
• CPC Class Codes: H01L 21/6831 using electrostatic chucks
• CPC Class Codes: Y10T 279/23 with magnetic or electrostatic means

Abstract

A pedestal assembly and method for controlling temperature of a substrate during processing is provided. In one embodiment, the pedestal assembly includes a support member that is coupled to a base by a material layer. The material layer has at least two regions having different coefficients of thermal conductivity. In another embodiment, the support member is an electrostatic chuck. In further embodiments, a pedestal assembly has channels formed between the base and support member for providing cooling gas in proximity to the material layer to further control heat transfer between the support member and the base, thereby controlling the temperature profile of a substrate disposed on the support member.

Claims

1. A substrate pedestal assembly comprising:

a substrate support member;

a base having a first surface; and

a material layer disposed between and contacting the first surface and the support member, wherein the material layer comprises a plurality of material regions, at least two of the material regions having different coefficients of thermal conductivity.

2. The substrate pedestal assembly of claim 1, wherein at least one region of the plurality of material regions has an anisotropic coefficient of thermal conductivity.

3. The substrate pedestal assembly of claim 1, wherein at least one region of the plurality of material regions is separated by a gap from an adjacent material region.

4. The substrate pedestal assembly of claim 1, wherein the material layer couples the support member to the first surface of the base.

5. The substrate pedestal assembly of claim 4, wherein at least one region of the material layer is thermally conductive adhesive material.

6. The substrate pedestal assembly of claim 4, wherein at least one region of the material layer comprises at least one thermally conductive adhesive tape.

7. The substrate pedestal assembly of claim 4, wherein the material layer is at least one of an acrylic based compound and silicon based compound.

8. The substrate support pedestal assembly of claim 1, wherein the material layer further comprises a ceramic filler selected from the group consisting of aluminum oxide (Al₂O₃), aluminum nitride (AlN), titanium diboride (TiB₂), and combinations thereof.

9. The substrate pedestal assembly of claim 1, wherein the regions of the material layer have coefficients of thermal conductivity in a range from 0.01 to 200 W/mK.

10. The substrate pedestal assembly of claim 1 further comprising at least one channel adapted to provide a heat transfer medium between the base and support member.

11. The substrate pedestal assembly of claim 10, wherein the at least one channel is at least partially formed in the base.

12. The substrate pedestal assembly of claim 10, wherein the at least one is at least partially formed in the support member.

13. The substrate pedestal assembly of claim 10, wherein the pressure of the heat transfer medium in the at least one channel may be selectively controlled in a range from about 760 to about 10 Torr.

14. The substrate pedestal assembly of claim 10, wherein the heat transfer medium is He.

15. The substrate pedestal assembly of claim 10, wherein the at least one channel is formed in the material layer.

16. The substrate pedestal assembly of claim 1, wherein the base comprises at least one conduit fluidly coupled to a heat transfer liquid source.

17. The substrate pedestal assembly of claim 10, wherein the channel is formed between material regions having different coefficients of thermal expansion.

18. The substrate pedestal assembly of claim 1, wherein the base comprises at least one embedded heater electrically coupled to a controlled power supply.

19. The substrate pedestal assembly of claim 1, wherein the base comprises at least one embedded insert formed from a material having a different coefficient of thermal conductivity than a material of an adjacent region of the base.

20. The substrate pedestal assembly of claim 19, wherein the material of the at least one embedded insert has a lower coefficient of thermal conductivity than the material of the adjacent region of the base.

21. The substrate pedestal assembly of claim 19, wherein the material of the at least one embedded insert has an anisotropic coefficient of thermal conductivity.

22. The substrate pedestal assembly of claim 1, wherein the support member comprises at least one embedded insert formed from a material having a different coefficient of thermal conductivity than a material of an adjacent region of the support member.

23. The substrate pedestal assembly of claim 22, wherein the material of the at least one embedded insert has a lower coefficient of thermal conductivity than the material of the adjacent region of the support member.

24. The substrate pedestal assembly of claim 22, wherein the material of the at least one embedded insert has an anisotropic coefficient of thermal conductivity.

25. The substrate pedestal assembly of claim 1, wherein a support member is an electrostatic chuck.

26. An apparatus for processing a substrate, comprising:

a process chamber;

a substrate pedestal assembly disposed in the chamber and comprising a base coupled to an electrostatic chuck by a material layer, the material layer comprising a at least two material regions having different coefficients of thermal conductivity;

a first channel formed between the chuck and base;

a source of at least one process gas coupled to the chamber; and

a source of heat transfer medium fluidly coupled to the first channel.

27. The apparatus of claim 26, wherein the material layer is an adhesive.

28. The apparatus of claim 26 further comprising a second channel disposed between the base and electrostatic chuck, wherein at least one attribute of cooling gas provided to the first channel is independently controllable relative to an attribute of cooling gas provided to the second channel.

29. A substrate support pedestal assembly comprising:

a temperature controlled base;

a support member coupled to the base; and

at least a first passage laterally disposed and at least partially bounded by the support member and the base, the first passage adapted to provide a heat transfer medium between an interface of the support member and the base.

30. The pedestal assembly of claim 29 further comprising:

a second channel laterally disposed between the base and the support member, the second channel adapted to provide a heat transfer medium between the substrate support and the first passage adapted to provide a heat transfer medium between an interface of the support member and the base, wherein the first and second passages are fluidly isolated.

31. The substrate support pedestal assembly of claim 29 further comprising:

an adhesive material layer coupling the base to the support member, wherein the first and second regions of the material layer have a different coefficients of thermal conductivity.

32. The substrate support pedestal assembly of claim 29, wherein the support member is an electrostatic chuck.

33. A substrate support pedestal assembly comprising:

a support member having an upper surface adapted to support a substrate during processing;

a temperature controlled base; and

an adhesive layer coupling the support member to the base, wherein the adhesive material layer has an anisotropic coefficient of thermal conductivity.

34. The substrate support pedestal assembly of claim 33, wherein the support member is an electrostatic chuck.

35. The substrate support pedestal assembly of claim 33 further comprising:

a plurality of passages formed between the support member and the base, the passages adapted to laterally distribute a heat transfer medium between an interface of the support member and the base.

36. A method for controlling the temperature profile of a substrate supported on a pedestal assembly comprising:

providing, to substrate support pedestal assembly having a support member disposed on a base, a heat transfer medium between an interface of the support member and the base; and

thermally regulating the base.

37. The method of claim 36, wherein the step of providing the heat transfer medium further comprises:

changing at least one attribute of the heat transfer medium provided to the passage during processing of a substrate disposed on the pedestal assembly.

38. The method of claim 37, wherein the step of controlling the attribute further comprises:

changing at least one of pressure, flow rate, temperature, density or composition of the heat transfer medium.

39. The method of claim 36 further comprising:

providing a heat transfer medium to a second passage laterally disposed in the interface between the support plate and the base, wherein the heat transfer medium disposed in the first passage is controlled independently than the heat transfer medium disposed in the second passage.

40. The method of claim 36, wherein the step of regulating the temperature of the base further comprises:

flowing a cooling liquid through a conduit disposed in the base.