Atomic layer deposited ZrTiO4 films

• US 20040214399A1
• Filed: 04/22/2003
• Published: 10/28/2004
• Est. Priority Date: 04/22/2003
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Ahn, Kie Y., Forbes, Leonard
• Granted Patent: US 7,183,186 B2
• Time in Patent Office: Days
• US Class Current: 438/287
• CPC Class Codes: H01L 21/02186 the material containing titanium, e.g. TiO2
• CPC Class Codes: H01L 21/02189 the material containing zirconium, e.g. ZrO2
• CPC Class Codes: H01L 21/02194 the material containing more than one metal element
• CPC Class Codes: H01L 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• CPC Class Codes: H01L 21/02205 the layer being characterised by the precursor material for deposition
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/28185 with a treatment, e.g. annealing, after the formation of the gate insulator and before the formation of the definitive gate conductor
• CPC Class Codes: H01L 21/28194 by deposition, e.g. evaporation, ALD, CVD, sputtering, laser deposition H01L21/28202 takes precedence
• CPC Class Codes: H01L 21/28202 in a nitrogen-containing ambient, e.g. nitride deposition, growth, oxynitridation, NH3 nitridation, N2O oxidation, thermal nitridation, RTN, plasma nitridation, RPN
• CPC Class Codes: H01L 21/3141 Deposition using atomic layer deposition techniques [ALD]
• CPC Class Codes: H01L 21/3142 of nano-laminates, e.g. alternating layers of Al203-Hf02
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/31641 Deposition of Zirconium oxides, e.g. ZrO2
• CPC Class Codes: H01L 29/513 the variation being perpendicular to the channel plane
• CPC Class Codes: H01L 29/517 the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate H01L29/518 takes precedence
• CPC Class Codes: H01L 29/518 the insulating material containing nitrogen, e.g. nitride, oxynitride, nitrogen-doped material
• CPC Class Codes: H01L 29/66181 Conductor-insulator-semiconductor capacitors, e.g. trench capacitors

Abstract

Dielectric layers having an atomic layer deposited oxide containing titanium and zirconium and a method of fabricating such a dielectric layer produce a reliable dielectric layer having an equivalent oxide thickness thinner than attainable using SiO₂. Pulsing a titanium-containing precursor onto a substrate, and pulsing a zirconium-containing precursor to form an oxide containing Zr and Ti by atomic layer deposition provides a dielectric layer with a relatively high dielectric constant as compared with silicon oxide. The pulsing of the titanium-containing precursor and the pulsing of the zirconium-containing precursor is controlled to provide a dielectric layer with a predetermined zirconium to titanium ratio. A zirconium-containing precursor to form the oxide containing Zr and Ti can include zirconium tertiary-butoxide.

Claims

1. A method of forming a film comprising:

pulsing a titanium-containing precursor onto a substrate; and

pulsing a zirconium tertiary-butoxide precursor to form a film containing ZrTiO₄ by atomic layer deposition.

2. The method of claim 1, wherein the method further includes controlling the pulsing of the titanium-containing precursor and the pulsing of the zirconium tertiary-butoxide precursor to provide the film with a predetermined ratio of Zr to Ti.

3. The method of claim 1, wherein pulsing a titanium-containing precursor includes pulsing a titanium-containing precursor selected from a group consisting of TiCl₄, TiI₄, Ti(OCH(CH₃)₂)₄, and Ti(OC₂H₅)₄.

4. The method of claim 1, wherein the method further includes performing a first pulsing of the titanium-containing precursor before pulsing the zirconium tertiary-butoxide precursor.

5. The method of claim 1, wherein the method further includes controlling the pulsing of the titanium-containing precursor and the pulsing of the zirconium tertiary-butoxide precursor to form a film containing ZrTiO₄ with a Zr/Ti ratio of about 0.4/0.6.

6. The method of claim 1, wherein the method further includes pulsing a reactant precursor after pulsing the titanium-containing precursor and pulsing a second reactant precursor after pulsing the zirconium tertiary-butoxide precursor, the reactant precursors selected from a group consisting of H₂O, H₂O₂, ROH, N₂O, O₃, and O₂.

7. The method of claim 1, wherein the method further includes maintaining the substrate at a temperature ranging from about 200°

C. to about 400°

C.

8. The method of claim 1, wherein the method further includes contacting the film containing ZrTiO₄ with a TiN-containing layer.

9. The method of claim 1, wherein the method further includes forming a silicon nitride layer between the substrate and the film containing ZrTiO₄.

10. A method of forming a film comprising:

pulsing a titanium-containing precursor onto a substrate; and

pulsing a zirconium tertiary-butoxide precursor to form a film containing a nanolaminate of ZrO₂ and TiO₂ by atomic layer deposition.

11. The method of claim 10, wherein the method further includes controlling the pulsing of the titanium-containing precursor and the pulsing of the zirconium tertiary-butoxide precursor, wherein the ratio of Zr to Ti in the nanolaminate of ZrO₂ and TiO₂ is selected to a predetermined ratio.

12. The method of claim 10, wherein pulsing a titanium-containing precursor includes pulsing a titanium-containing precursor selected from a group consisting of TiCl₄, TiI₄, Ti(OCH(CH₃)₂)₄, and Ti(OC₂H₅)₄.

13. A method of forming a capacitor, comprising:

forming a first conductive layer on a substrate;

forming a dielectric layer on the first conductive layer; and

forming a second conductive layer on the dielectric layer, wherein forming the dielectric layer includes;

pulsing a titanium-containing precursor onto the first conductive layer; and

pulsing a zirconium tertiary-butoxide precursor to form a film containing a nanolaminate of ZrO₂ and TiO₂ by atomic layer deposition.

14. The method of claim 13, wherein the method further includes controlling the pulsing of the titanium-containing precursor and the pulsing of the zirconium tertiary-butoxide precursor, wherein the ratio of Zr to Ti in the nanolaminate of ZrO₂ and TiO₂ is selected to a predetermined ratio.

15. The method of claim 13, wherein pulsing a titanium-containing precursor includes pulsing a titanium-containing precursor selected from a group consisting of TiCl₄, TiI₄, Ti(OCH(CH₃)₂)₄, and Ti(OC₂H₅)₄.

16. The method of claim 13, wherein the method further includes performing a first pulsing of the titanium-containing precursor before pulsing the zirconium tertiary-butoxide precursor.

17. The method of claim 13, wherein the method further includes forming at least one of the first and second conductive layers by atomic layer deposition to contain TiN.

18. The method of claim 13, wherein the method further includes forming a silicon nitride layer between the first conductive layer and the film containing the nanolaminate of ZrO₂ and TiO₂.

19. A method of forming a transistor comprising:

forming a source region and a drain region in a substrate, the source region and the drain region separated by a body region;

forming a dielectric layer on the body region between the source and drain regions; and

coupling a gate to the dielectric layer, wherein forming the dielectric layer includes;

pulsing a titanium-containing precursor onto the body region;

pulsing a zirconium tertiary-butoxide precursor to form an oxide containing Zr and Ti by atomic layer deposition.

20. The method of claim 19, wherein the method further includes controlling the pulsing of the titanium-containing precursor and the pulsing of the zirconium tertiary-butoxide precursor to form the oxide with a predetermined ratio of Zr to Ti.

21. The method of claim 19, wherein pulsing a titanium-containing precursor includes pulsing a titanium-containing precursor selected from a group consisting of TiCl₄, TiI₄, Ti(OCH(CH₃)₂)₄, and Ti(OC₂H₅)₄.

22. The method of claim 19, wherein forming an oxide containing Zr and Ti includes forming an oxide containing ZrTiO₄ with a predetermined ratio of Zr to Ti.

23. The method of claim 19, wherein forming an oxide containing Zr and Ti includes forming an oxide containing a nanolaminate of ZrO₂ and TiO₂ with a predetermined ratio of Zr to Ti.

24. The method of claim 19, wherein the method further includes controlling the pulsing of the titanium-containing precursor and the pulsing of the zirconium tertiary-butoxide precursor to form a film containing ZrTiO₄ with a Zr/Ti ratio of about 0.4/0.6.

25. The method of claim 19, wherein coupling a gate to the dielectric layer includes forming a gate containing TiN.

26. The method of claim 19, wherein the method further includes forming a silicon nitride layer between the body region and the dielectric layer.

27. A method of forming a memory comprising:

forming a number of access transistors including forming at least one dielectric layer containing ZrTiO₄ on a body region in a substrate between a source region and a drain region; and

forming a number of word lines coupled to the number of access transistors, wherein forming the dielectric layer includes;

pulsing a titanium-containing precursor onto the body region; and

pulsing a zirconium tertiary-butoxide precursor to form the ZrTiO₄ by atomic layer deposition.

28. The method of claim 27, wherein the method further includes forming the ZrTiO₄ with a predetermined ratio of zirconium to titanium.

29. The method of claim 27, wherein pulsing a titanium-containing precursor includes pulsing a titanium-containing precursor selected from a group consisting of TiCl₄, TiI₄, Ti(OCH(CH₃)₂)₄, and Ti(OC₂H₅)₄.

30. The method of claim 27, wherein the method further includes performing a first pulsing of the titanium-containing precursor before pulsing the zirconium tertiary-butoxide precursor.

31. The method of claim 27, wherein the method further includes controlling the pulsing of the titanium-containing precursor and the pulsing of the zirconium tertiary-butoxide precursor to form a film containing ZrTiO₄ with a Zr/Ti ratio of about 0.4/0.6.

32. A method of forming an electronic system comprising:

providing a controller; and

coupling a device to the controller, wherein at least one of the controller and the device includes a dielectric layer having an oxide containing Zr and Ti, the dielectric layer formed by a method including;

pulsing a titanium-containing precursor onto a substrate; and

pulsing a zirconium tertiary-butoxide precursor to form the oxide containing Zr and Ti by atomic layer deposition.

33. The method of claim 32, wherein the method further includes controlling the pulsing of the titanium-containing precursor and the pulsing of the zirconium tertiary-butoxide precursor to form the oxide having a predetermined ratio of Zr to Ti.

34. The method of claim 32, wherein pulsing a titanium-containing precursor includes pulsing a titanium-containing precursor selected from a group consisting of TiCl₄, Ti₄, Ti(OCH(CH₃)₂)₄, and Ti(OC₂H₅)₄.

35. The method of claim 32, wherein the method further includes controlling the pulsing of the titanium-containing precursor onto the substrate and the pulsing of the zirconium tertiary-butoxide precursor to form the oxide as ZrTiO₄.

36. The method of claim 32, wherein the method further includes controlling the pulsing of the titanium-containing precursor and the pulsing of the zirconium tertiary-butoxide precursor to form the oxide with a Zr/Ti ratio of about 0.4/0.6.

37. The method of claim 32, wherein forming a dielectric layer having an oxide containing Zr and Ti includes forming an oxide film containing a nanolaminate of ZrO₂ and TiO₂.

38. The method of claim 32, wherein providing a controller and coupling a device to the controller includes providing a processor, and coupling a memory device to the controller.

39. A device having a dielectric layer comprising:

an oxide layer containing Zr and Ti disposed on a substrate;

the oxide layer containing Zr and Ti formed by a method including;

pulsing a titanium-containing precursor onto a substrate; and

pulsing a zirconium tertiary-butoxide precursor to form an oxide containing Zr and Ti by atomic layer deposition.

40. The device of claim 39, wherein the oxide layer containing Zr and Ti has a predetermined ratio of zirconium to titanium.

41. The device of claim 39, wherein the oxide layer containing Zr and Ti includes ZrTiO₄.

42. The device of claim 39, further including a silicon nitride layer between the substrate and the dielectric layer.

43. The device of claim 39, further including a contact containing TiN connected to the dielectric layer.

44. The device of claim 39, wherein the oxide layer containing Zr and Ti includes a nanolaminate of ZrO₂ and TiO₂.

45. A capacitor, comprising:

a first conductive layer;

a dielectric layer containing ZrTiO₄ disposed on the first conductive layer; and

a second conductive layer disposed on the dielectric layer;

the dielectric layer formed by a method including;

pulsing a titanium-containing precursor onto the body region; and

pulsing a zirconium tertiary-butoxide precursor to form a film containing ZrTiO₄ by atomic layer deposition.

46. The capacitor of claim 45, wherein the film containing ZrTiO₄ includes a film containing ZrTiO₄ with a predetermined ratio of Zr to Ti.

47. The capacitor of claim 45, wherein the layer containing ZrTiO₄ includes a film containing ZrTiO₄ with a ZrTi ratio of about 0.4/0.6.

48. The capacitor of claim 45, wherein second conductive layer includes TiN.

49. A transistor comprising:

a body region in a substrate between a source region and a drain region;

a dielectric layer containing ZrTiO₄ disposed on the body region between the source region and the drain region; and

a gate coupled to the dielectric layer;

the dielectric layer formed by a method including;

pulsing a titanium-containing precursor onto the body region; and

pulsing a zirconium tertiary-butoxide precursor to form the ZrTiO₄ by atomic layer deposition.

50. The transistor of claim 49, wherein the ZrTiO₄ has a predetermined ratio of zirconium to titanium.

51. The transistor of claim 49, further including a silicon nitride layer between the body region and the dielectric layer.

52. The transistor of claim 49, wherein the gate includes TiN.

53. The transistor of claim 49, wherein the dielectric layer has an equivalent oxide thickness (t_eq) of less than about 10 Angstroms.

54. A memory comprising:

a number of access transistors, at least one access transistor including a gate coupled to a dielectric layer, the dielectric layer disposed on a body region in a substrate between a source region and a drain region; and

a number of bit lines coupled to the number of access transistors;

the dielectric layer formed by a method including;

pulsing a titanium-containing precursor onto a substrate; and

pulsing a zirconium tertiary-butoxide precursor to form an oxide containing Zr and Ti by atomic layer deposition.

55. The memory of claim 54, wherein the oxide containing Zr and Ti has a predetermined ratio of Zr to Ti.

56. The memory of claim 54, wherein the gate includes TiN.

57. The memory of claim 54, wherein the dielectric layer has an equivalent oxide thickness (t_eq) of less than about 10 Angstroms.

58. An electronic system comprising:

a controller;

a bus; and

an electronic device coupled to the controller by the bus, wherein at least one of the controller and the electronic device includes a dielectric layer having an oxide containing Zr and Ti, the dielectric layer formed by a method including;

pulsing a titanium-containing precursor; and

pulsing a zirconium tertiary-butoxide precursor to form the oxide containing Zr and Ti by atomic layer deposition.

59. The electronic system of claim 58, wherein the oxide containing Zr and Ti includes ZrTiO₄.

60. The electronic system of claim 58, wherein the oxide containing Zr and Ti includes ZrTiO₄ with a predetermined ratio of zirconium to titanium.

61. The electronic system of claim 58, wherein the oxide containing Zr and Ti includes a nanolaminate of ZrO₂ and TiO₂.

62. The electronic system of claim 58, wherein the dielectric layer forms a gate dielectric of a transistor with a gate containing TiN coupled to the dielectric layer.

63. The electronic system of claim 58, wherein the dielectric layer has an equivalent oxide thickness (t_eq) of less than about 10 Angstroms.

64. The electronic system of claim 58, wherein the controller is a processor and the electronic device is a memory device.