Thin film deposition

• US 20070099438A1
• Filed: 10/28/2005
• Published: 05/03/2007
• Est. Priority Date: 10/28/2005
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Ding, Peijun, Wang, Hougong, Ye, Mengqi, Liu, Zhendong
• Granted Patent: US 7,884,032 B2
• Time in Patent Office: Days
• US Class Current: 438/778
• CPC Class Codes: C23C 14/345 using substrate bias
• CPC Class Codes: C23C 14/35 by application of a magnetic field, e.g. magnetron sputtering C23C14/3457 takes precedence
• CPC Class Codes: H01L 21/02046 Dry cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/28017 the insulator being formed after the semiconductor body, the semiconductor being silicon
• CPC Class Codes: H01L 21/2855 by physical means, e.g. sputtering, evaporation H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence

Abstract

A system, method and apparatus is capable of producing layers of various materials stacked on one another on a substrate without exposing the substrate to the pressure and contaminants of ambient air until the stack is complete. In one aspect, the stack of layers can include both an insulative layer of one or more insulative films, and a conductive metal layer of one or more conductive metal layer films. In another aspect, a bias signal of positive and negative voltage pulses may be applied to a target of a deposition chamber to facilitate deposition of the target material in a suitable fashion. In yet another aspect, one or more of the deposition chambers may have associated therewith a pump which combines a turbomolecular pump and a cryogenic pump to generate an ultra high vacuum in that chamber. Other features are described and claimed.

Claims

1. A method, comprising:

depositing at least one insulative layer on a substrate in a first deposition chamber coupled to a robot chamber of a mainframe of a plafform;

transferring said substrate through a robot chamber of said mainframe to a second deposition chamber coupled to a robot chamber of said mainframe;

maintaining at a vacuum pressure each robot chamber of said mainframe through which said substrate is transferred as said substrate is transferred from said first deposition chamber to a metal deposition chamber of said system; and

depositing at least one metal conductive layer on said insulative layer in a metal deposition chamber of said system.

2. The method of claim 1 wherein said insulative layer depositing includes depositing a plurality of insulative layers and said metal conductive layer depositing includes depositing a plurality of metal conductive layers on said insulative layer.

3. The method of claim 1 wherein said insulative layer depositing includes providing a chemical vapor into said first chamber and depositing a chemical onto said substrate from said chemical vapor.

4. The method of claim 1 wherein said insulative layer depositing includes sputtering a target in said first chamber and introducing a reactive gas into said chamber to chemically react with said sputtered target material to form a deposition material for deposition on said substrate.

5. The method of claim 1 wherein said metal conductive layer depositing includes sputtering a target of a conductive metal in said second chamber.

6. The method of claim 1 wherein said metal conductive layer depositing includes depositing a metal film using a atomic layer deposition chamber as said second deposition chamber.

7. The method of claim 1 wherein said metal conductive layer depositing includes depositing a metal film using a chemical vapor deposition chamber as said second chamber.

8. The method of claim 1 wherein said metal conductive layer depositing includes depositing a protective metal conductive layer on said insulative layer at a first deposition rate and a bulk metal conductive layer on said protective metal conductive layer at a second deposition rate greater than said first deposition rate and wherein said protective metal conductive layer is thinner than said bulk metal conductive layer.

9. The method of claim 8 wherein said protective layer is deposited at a first pressure and said bulk layer is deposited at a second pressure lower than said first pressure.

10. The method of claim 8 wherein said protective layer is deposited using an atomic layer deposition chamber in said second chamber.

11. The method of claim 8 wherein said protective layer provides at least one of providing enhanced adhesion between said insulative layer and said bulk layer, providing diffusion barrier between said insulative layer and said bulk layer, and modulating the work function of said bulk layer.

12. The method of claim 10 further comprising transferring said substrate through a robot chamber of said mainframe to a third deposition chamber coupled to a robot chamber of said mainframe wherein said bulk layer is deposited using a physical vapor deposition chamber as said third deposition chamber;

and maintaining at a vacuum pressure each robot chamber of said mainframe through which said substrate is transferred as said substrate is transferred from said second deposition chamber to said third deposition chamber.

13. The method of claim 1 wherein said insulative layer and metal conductive layer are part of a gate stack.

14. The method of claim 1 further excluding cleaning the insulative layer prior to depositing the metal conductive layer on said insulative layer.

15. The method of claim 1 wherein said first deposition chamber is a physical vapor deposition chamber having a target and wherein said insulative layer depositing includes pulsing said target with negative voltage pulses alternating with positive voltage pulses.

16. The method of claim 1 further comprising absorbing water vapor from said second chamber using a cryogenic pump as one stage of a combination pump and pumping other gases including toxic gasses from said second chamber using a turbomolecular pump as another stage of said combination pump.

17. The method of claim 1 further comprising supplying gasses to said second chamber using a gas box and purging gasses from gas lines of said gas box using a purge gas.

18. The method of claim 1 further comprising transferring said substrate through a robot chamber of said mainframe to a preclean chamber coupled to a robot chamber of said mainframe;

cleaning said substrate in-situ in said preclean chamber prior to said insulative layer deposition;

transferring said substrate through a robot chamber of said mainframe from said preclean chamber to said first deposition chamber; and

maintaining at a vacuum pressure each robot chamber of said mainframe through which said substrate is transferred as said substrate is transferred to said preclean chamber of said mainframe and as said substrate is transferred from said preclean chamber to said first deposition chamber.

19. The method of claim 18 wherein NH₄F formed in a remote plasma is flown into the preclean chamber through showerheads and reaches the substrate surface, NH₄F reacts with native oxide previously formed on a silicon substrate surface and forms (NH₄)₂SiF₆, which subsequently sublimates and leaves the wafer surface during an annealing process carried out in the same chamber.

20. The method of claim 1 further comprising annealing said substrate in-situ in said first deposition chamber following said insulative layer deposition.

21. The method of claim 1 further comprising transferring said substrate through a robot chamber of said mainframe from said first deposition chamber to a decoupled plasma nitridation (DPN) chamber coupled to a robot chamber of said mainframe;

nitridating said insulative layer in said DPN chamber following said insulative layer deposition;

transferring said substrate through a robot chamber of said mainframe from said DPN chamber to said second deposition chamber; and

maintaining at a vacuum pressure each robot chamber of said mainframe through which said substrate is transferred as said substrate is transferred to said DPN chamber and as said substrate is transferred from said DPN chamber to said second deposition chamber.

22. The method of claim 21 further comprising annealing said substrate in-situ in said DPN chamber or a RTP chamber following said nitridating said insulative layer.

23. A system for use with a substrate, comprising:

a mainframe which includes at least one robot chamber, each robot chamber having a substrate transfer robot;

at least one pump coupled to a robot chamber of said mainframe;

a controller;

a first deposition chamber coupled to a robot chamber of said mainframe and adapted to deposit an insulative layer on said substrate in response to said controller; and

a second deposition chamber coupled to a robot chamber of said mainframe and adapted to deposit at least one metal conductive layer on said insulative layer in response to said controller;

wherein said controller is adapted to cause at least one robot of said mainframe to transfer said substrate from said first deposition chamber, through at least one robot chamber of said mainframe and to said second deposition chamber and to cause a pump of said mainframe to maintain at a vacuum pressure each robot chamber of said mainframe through which said substrate is transferred as said substrate is transferred from said first chamber to said second chamber of said system.

24. The system of claim 23 wherein said second deposition chamber is adapted to deposit a plurality of metal conductive layers on said insulative layer in response to said controller.

25. The system of claim 24 wherein said second deposition chamber is adapted to anneal said metal conductive layer in situ following said metal layer deposition.

26. The system of claim 23 wherein said first chamber is a chemical vapor deposition chamber.

27. The system of claim 23 wherein said first chamber is a sputtering chamber having a sputtering target.

28. The system of claim 23 wherein said second chamber is a sputtering chamber having a sputtering target.

29. The system of claim 23 wherein said second chamber is an atomic layer deposition chamber.

30. The system of claim 23 wherein said second chamber is a chemical vapor deposition chamber.

31. The system of claim 23 wherein said controller is adapted to control said second chamber to deposit a protective metal conductive layer on said insulative layer at a first deposition rate and a bulk metal conductive layer on said protective metal conductive layer at a second deposition rate greater than said first deposition rate and wherein said protective metal conductive layer is thinner than said bulk metal conductive layer.

32. The system of claim 31 wherein said controller is adapted to control said second deposition chamber to deposit said protective layer at a first pressure and said bulk layer at a second pressure lower than said first pressure.

33. The system of claim 23 wherein said controller is adapted to control said second chamber to deposit a protective metal conductive layer on said insulative layer at a first deposition rate, said system further comprising a third deposition chamber, wherein said controller is adapted to control said third deposition chamber to deposit a bulk metal conductive layer on said protective metal conductive layer at a second deposition rate greater than said first deposition rate and wherein said protective metal conductive layer is thinner than said bulk metal conductive layer.

34. The system of claim 33 wherein said second deposition chamber is an atomic layer deposition chamber wherein said protective layer is deposited using said atomic layer deposition chamber as said second chamber.

35. The system of claim 34 further comprising a physical vapor deposition chamber coupled to a robot chamber of said mainframe wherein said bulk layer is deposited using said physical vapor deposition chamber and wherein said controller is adapted to cause at least one robot of said mainframe to transfer said substrate from said second deposition chamber, through at least one robot chamber of said mainframe and to said physical vapor deposition chamber and to cause a pump of said mainframe to maintain at a vacuum pressure each robot chamber of said mainframe through which said substrate is transferred as said substrate is transferred from said second chamber to said physical vapor deposition chamber.

36. The system of claim 23 wherein said insulative layer and metal conductive layer are part of a gate stack.

37. The system of claim 23 wherein said controller is adapted to control said system to deposit the metal conductive layer on said insulative layer in the absence of cleaning said insulative layer prior to deposition of said metal conductive layer.

38. The system of claim 23 wherein said first deposition chamber is a physical vapor deposition chamber having a target and wherein said controller is adapted to control said first deposition chamber to pulse said target with negative voltage pulses alternating with positive voltage pulses during said insulative layer depositing.

39. The system of claim 23 further comprising a combination pump which includes as a first stage, a cryogenic pump adapted to absorb water vapor from said first chamber, said combination pump further including as a second stage, a turbomolecular pump adapted to pump other gases including toxic gasses from said first chamber.

40. The system of claim 23 further comprising a combination pump which includes as a first stage, a cryogenic pump adapted to absorb water vapor from said second chamber, said combination pump further including as a second stage, a turbomolecular pump adapted to pump other gases including toxic gasses from said second chamber.

41. The system of claim 23 further comprising a gas box having a plurality of gas lines adapted to supply gasses to said second chamber and further adapted to purge gasses from said gas lines of said gas box using a purge gas.

42. The system of claim 23 further comprising a preclean chamber coupled to a robot chamber of said mainframe wherein said controller is adapted to cause at least one robot of said mainframe to transfer said substrate through a robot chamber of said mainframe to said preclean chamber and cause said substrate to be cleaned in-situ in said preclean chamber prior to said insulative layer deposition;

and to cause at least one robot of said mainframe to transfer said substrate through a robot chamber of said mainframe from said preclean chamber to said first deposition chamber; and

to cause a pump of said mainframe to maintain at a vacuum pressure each robot chamber of said mainframe through which said substrate is transferred as said substrate is transferred to said preclean chamber of said mainframe and as said substrate is transferred from said preclean chamber to said first deposition chamber.

43. The system of claim 42 wherein said preclean chamber has showerheads adapted to provide NH₄F formed in a remote plasma and adapted to anneal the substrate to sublimate (NH₄)₂SiF₆, from the substrate surface.

44. The system of claim 23 further wherein said first deposition chamber is adapted to anneal said substrate in-situ in said first deposition chamber following said insulative layer deposition.

45. The system of claim 23 further comprising a rapid thermal processing (RTP) chamber coupled to said mainframe and adapted to anneal a deposition on said chamber.

46. The system of claim 23 further comprising a decoupled plasma nitridation (DPN) chamber coupled to a robot chamber of said mainframe, wherein said controller is adapted to cause at least one robot of said mainframe to transfer said substrate through a robot chamber of said mainframe from said first deposition chamber to said DPN chamber to nitridate said insulative layer in said DPN chamber following said insulative layer deposition;

wherein said controller is adapted to cause at least one robot of said mainframe to transfer said substrate through a robot chamber of said mainframe from said DPN chamber to said second deposition chamber; and

to cause a pump of said mainframe to maintain at a vacuum pressure each robot chamber of said mainframe through which said substrate is transferred as said substrate is transferred to said DPN chamber and as said substrate is transferred from said DPN chamber to said second deposition chamber.

47. The system of claim 46 wherein said DPN chamber is further adapted to anneal said substrate in-situ in said DPN chamber following said nitridating said insulative layer.

48. A system for use with a substrate, comprising:

a mainframe which includes at least one robot chamber, each robot chamber having a substrate transfer robot;

at least one pump coupled to a robot chamber of said mainframe;

a controller;

a first deposition chamber coupled to a robot chamber of said mainframe and adapted to deposit an insulative layer on said substrate in response to said controller wherein said first deposition chamber is a physical vapor deposition chamber having a target and wherein said controller is adapted to control said first deposition chamber to pulse said target with negative voltage pulses alternating with positive voltage pulses during said insulative layer depositing;

at least one metal deposition chamber coupled to a robot chamber of said mainframe wherein said controller is adapted to control a metal deposition chamber of said system to deposit a protective conductive metal layer on said insulative layer at a first deposition rate and a first pressure and a to control a metal deposition chamber of said system to deposit a bulk conductive metal layer on said protective metal layer at a second deposition rate greater than said first deposition rate and a second pressure lower than said first pressure and wherein said protective metal layer is thinner than said bulk metal layer;

a first combination pump coupled to said first deposition chamber, said first pump including as a first stage, a cryogenic pump adapted to absorb water vapor from said first chamber, said first combination pump further including as a second stage, a turbomolecular pump adapted to pump other gasses including toxic gasses from said first chamber;

a second combination pump coupled to a metal deposition chamber of said system, said second pump including as a first stage, a cryogenic pump adapted to absorb water vapor from a metal deposition chamber of said system, said combination pump further including as a second stage, a turbomolecular pump adapted to pump other gasses including toxic gasses from a metal deposition chamber of said system; and

a gas box coupled to a metal deposition chamber of said system and having a plurality of gas lines adapted to supply gasses to a metal deposition chamber of said system and further adapted to purge gasses from said gas lines of said gas box using a purge gas;

wherein said controller is adapted to cause at least one robot of said mainframe to transfer said substrate from said first deposition chamber, through at least one robot chamber of said mainframe and to a metal deposition chamber and to cause a pump of said mainframe to maintain at a vacuum pressure each robot chamber of said mainframe through which said substrate is transferred as said substrate is transferred from said first chamber to a metal deposition chamber of said system; and

wherein said controller is adapted to control said system to deposit the protective metal conductive layer on said insulative layer in the absence of cleaning said insulative layer prior to deposition of said protective metal conductive layers and wherein said insulative layer and metal conductive layers are part of a gate stack.

49. A method, comprising:

depositing a protective metal conductive layer on an insulative layer in an atomic layer deposition chamber of a system; and

depositing a bulk metal conductive layer on said protective metal conductive layer in a second deposition chamber of said system wherein said bulk metal conductive layer has a thickness greater than said protective metal conductive layer.

50. The method of claim 49 wherein said depositing a layer in an atomic layer deposition chamber includes pulsing a compound containing said metal.

51. The method of claim 49 wherein said protective metal conductive layer has a thickness of 30 angstroms or less.

52. The method of claim 49 wherein said bulk metal conductive layer depositing includes sputtering a target of a conductive metal in a physical vapor deposition chamber.

53. The method of claim 49 wherein said insulative layer, protective layer and bulk layer are part of a gate stack.

54. The method of claim 53 further comprising depositing a capping layer on said bulk layer.

55. A device, comprising:

a substrate;

an insulation layer deposited on said substrate;

a protective layer of a conductive metal deposited on said insulative layer, said protective layer comprising at least one atomic layer chamber deposited film of said conductive metal; and

a bulk metal conductive layer deposited on said protective metal conductive layer, said bulk layer comprising at least one physical vapor deposition chamber deposited film having a thickness greater than said protective metal conductive layer.

56. The device of claim 55 further comprising a capping layer deposited on said bulk metal conductive layer.