Methods of forming atomic layers of a material on a substrate by sequentially introducing precursors of the material

• US 20040018307A1
• Filed: 02/21/2003
• Published: 01/29/2004
• Est. Priority Date: 07/26/2002
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, In-Sung, Yeo, Jae-Hyun, Chung, Jeong-Hee
• Granted Patent: US 7,201,943 B2
• Time in Patent Office: Days
• US Class Current: 427/255.36
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• CPC Class Codes: C23C 16/45531 specially adapted for making ternary or higher compositions
• CPC Class Codes: C23C 16/45542 Plasma being used non-continuously during the ALD reactions
• CPC Class Codes: C23C 16/45553 characterized by the use of precursors specially adapted for ALD
• CPC Class Codes: H01L 21/02183 the material containing tantalum, e.g. Ta2O5
• CPC Class Codes: H01L 21/02186 the material containing titanium, e.g. TiO2
• CPC Class Codes: H01L 21/02194 the material containing more than one metal element
• CPC Class Codes: H01L 21/02205 the layer being characterised by the precursor material for deposition
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/02277 the reactions being activated by other means than plasma or thermal, e.g. photo-CVD
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02337 treatment by exposure to a gas or vapour
• CPC Class Codes: H01L 21/02348 treatment by exposure to UV light
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/31683 of metallic layers, e.g. Al deposited on the body, e.g. formation of multi-layer insulating structures
• CPC Class Codes: H01L 28/90 having vertical extensions

Abstract

A thin film is formed using an atomic layer deposition process, by introducing a first reacting material including tantalum precursors and titanium precursors onto a substrate. A portion of the first reacting material is chemisorbed onto the substrate. Then, a second reacting material including oxygen is introduced onto the substrate. A portion of the second reacting material is also chemisorbed onto the substrate, to form an atomic layer of a solid material on the substrate. The solid material may be used as a dielectric layer of the capacitor and/or a gate dielectric layer of the transistor.

Claims

1. A method of forming a thin film layer through an atomic layer deposition process, comprising:

introducing a first reacting material including a tantalum precursor and a titanium precursor to a substrate to chemisorb a portion of the first reacting material onto the substrate; and

introducing a second reacting material including oxygen to the substrate to chemisorb a portion of the second reacting materials onto the substrate and to form a solid material thereon.

2. The method of forming a thin film layer as claimed in claim 1, wherein the tantalum precursor includes at least one selected from the group consisting of TaCl₅, Ta(OCH₃)₅, Ta(OC₂H₅)₅, Ta(OC₃H₇)₅, Ta(OC₄H₉)₅, Ta(OC₂H₅)(OC₃H₇)₄, and TAT-DAME, and the titanium precursor includes at least one selected from the group consisting of TiCl₄, Ti(OCH₃)₄, Ti(OC₂H₅)₄, Ti(OC₃H₇)₄, Ti(OC₄H₉)₄, Ti(OC₂H₅)(OC₃H₇)₄, Ti(OC₃H₇)₂(O₂C₁₁H₁₉)₂, and Ti(OEt₂)(DAME)₂.

3. The method of forming a thin film layer as claimed in claim 1, wherein the first reacting material comprises mixed precursors including the tantalum precursor and the titanium precursor.

4. The method of forming a thin film layer as claimed in claim 3, wherein the mixed precursors include TAT-DAME/Ti(OEt)₂(DAME)₂ and/or Ta(OC₂H₅)₅/Ti(OC₂H₅)₄.

5. The method of forming a thin film layer as claimed in claim 3, wherein the mixed precursors are introduced onto the substrate through one line such that the tantalum precursor and the titanium precursor are mixed.

6. The method of forming a thin film layer as claimed in claim 1, wherein the second reacting material is at least one selected from the group consisting of O₂, O₃, H₂O, N₂O, and alcohols including —

OH group.

7. The method of forming a thin film layer as claimed in claim 1, wherein the second reacting material is activated by ultraviolet rays, or is activated in a state of a plasma gas or a remote plasma gas.

8. The method of forming a thin film layer as claimed in claim 1, wherein the solid material includes a tantalum titanium oxide (TaTiO) thin film.

9. The method of forming a thin film layer as claimed in claim 1, wherein the solid material is a dielectric layer of a capacitor of a semiconductor device.

10. The method of forming a thin film layer as claimed in claim 1, wherein the solid material is a gate dielectric layer of a transistor.

11. The method of forming a thin film layer as claimed in claim 1, wherein an atomic ratio of tantalum to titanium in the solid material is about 1:

0.01 to 0.2.

12. The method of forming a thin film layer as claimed in claim 1, wherein the first reacting material and the second reacting material are introduced onto the substrate using an inert gas.

13. The method of forming a thin film layer as claimed in claim 1, wherein the first reacting material and the second reacting material are introduced at about 200°

C. to about 450°

C., and under pressure of about 0.1 to about 10 Torr.

14. The method of forming a thin film layer as claimed in claim 1, wherein the introducing a first reacting material and the introducing a second reacting material are repeated at least once in sequence.

15. The method of forming a thin film layer as claimed in claim 1, wherein the introducing a first reacting material further comprises purging at least some non-chemisorbed first reacting material from the substrate, and the introducing a second reacting material further comprises purging at least some non-chemisorbed second reacting material from the substrate.

16. The method of forming a thin film layer as claimed in claim 15, wherein the first and the second reacting materials are purged by using an inert gas.

17. The method of forming a thin film layer as claimed in claim 1, further comprising heat-treating the solid material after the introducing a second reacting material.

18. The method of forming a thin film layer as claimed in claim 17, wherein the heat-treating the solid material is carried out by irradiating ozone (O₃) ultraviolet rays at about 650°

C. to about 750°

C.

19. The method of forming a thin film layer as claimed in claim 17, wherein the heat-treating the solid material is carried out by flowing oxygen at about 700°

C. to about 800°

C.

20. The method of forming a thin film layer as claimed in claim 17, wherein the heat-treating the solid material is carried out at least once.

21. A method of forming a capacitor of a semiconductor device, comprising:

forming a lower electrode of the capacitor on a substrate;

forming a dielectric layer of the capacitor including titanium tantalum oxide on the substrate by discontinuously introducing a first reacting material, a second reacting material, and a purge gas onto the lower electrode, chemisorbing a portion of the first reacting material and the second reacting material onto the substrate, and purging at least some non-chemisorbed first and second reacting materials from the substrate, wherein the first reacting material includes a tantalum precursor and a titanium precursor, and the second reacting material includes oxygen; and

forming an upper electrode of the capacitor on the dielectric layer.

22. The method of forming a capacitor of a semiconductor device as claimed in claim 21, wherein the lower electrode includes at least one selected from the group consisting of TiN, WN, Ru, Pt, and Ir, and the upper electrode includes at least one selected from the group consisting of polysilicon, TiN, WN, Ru, Pt, and Ir.

23. The method of forming a capacitor of a semiconductor device as claimed in claim 21, wherein the lower electrode has an aspect ratio ranging from about 5:

1 to about 15;

1.

24. The method of forming a capacitor of a semiconductor device as claimed in claim 21, wherein the tantalum precursor includes at least one selected from the group consisting of TaCl₅, Ta(OCH₃)₅, Ta(OC₂H₅)₅, Ta(OC₃H₇)₅, Ta(OC₄H₉)₅, Ta(OC₂H₅)(OC₃H₇)₄, and TAT-DAME, the titanium precursor includes at least one selected from the group consisting of TiCl₄, Ti(OCH₃)₄, Ti(OC₂H₅)₄, Ti(OC₃H₇)₄, Ti(OC₄H₉)₄, Ti(OC₂H₅)(OC₃H₇)₄, Ti(OC₃H₇)₂(O₂C₁₁H₁₉)₂, and Ti(OEt₂)(DAME)₂, and the second reacting materials include at least one selected from the group consisting of O₂, O₃, H₂O, N₂O, and alcohols including —

OH group.

25. The method of forming a capacitor of a semiconductor device as claimed in claim 21, wherein the first reacting material comprises a mixed precursor including the tantalum precursor and the titanium precursor, and is introduced through one line such that the tantalum precursor and the titanium precursor are mixed.

26. The method of forming a capacitor of a semiconductor device as claimed in claim 25, wherein the mixed precursor includes TAT-DAME/Ti(OEt)₂(DAME)₂ and/or Ta(OC₂H₅)₅/Ti(OC₂H₅)₄.

27. The method of forming a capacitor of a semiconductor device as claimed in claim 21, wherein the dielectric layer has a thickness of about 5 Å

to about 20 Å

.

28. The method of forming a capacitor of a semiconductor device as claimed in claim 21, further comprising the step of heat-treating the dielectric layer in an oxygen ambient.

29. A method of forming a transistor, comprising:

forming a gate dielectric layer of the transistor including tantalum titanium oxide on a substrate by discontinuously introducing a first reacting material, a second reacting material, and a purge gas onto the substrate, chemisorbing a portion of the first reacting material and the second reacting material onto the substrate, and purging at least some non-chemisorbed first and second reacting materials from the substrate, wherein the first reacting material includes a tantalum precursor and a titanium precursor and the second reacting material includes oxygen;

forming a gate electrode on the gate dielectric layer; and

forming source and drain regions in the substrate.

30. The method of forming a transistor as claimed in claim 29, wherein the tantalum precursor includes at least one selected from the group consisting of TaCl₅, Ta(OCH₃)₅, Ta(OC₂H₅)₅, Ta(OC₃H₇)₅, Ta(OC₄H₉)₅, Ta(OC₂H₅)(OC₃H₇)₄, and TAT-DAME, the titanium precursor includes at least one selected from the group consisting of TiCl₄, Ti(OCH₃)₄, Ti(OC₂H₅)₄, Ti(OC₃H₇)₄, Ti(OC₄H₉)₄, Ti(OC₂H₅)(OC₃H₇)₄, Ti(OC₃H₇)₂(O₂C₁₁H₁₉)₂, and Ti(OEt₂)(DAME)₂, and the second reacting material includes at least one selected from the group consisting of O₂, O₃, H₂O, N₂O, and alcohols including —

OH group.

31. The method of forming a transistor as claimed in claim 29, wherein the first reacting material comprises a mixed precursor including the tantalum precursor and the titanium precursor, and is introduced through one line such that the tantalum precursor and the titanium precursor are mixed.

32. The method of forming a transistor as claimed in claim 29, wherein the mixed precursor includes TAT-DAME/Ti(OEt)₂(DAME)₂ and/or Ta(OC₂H₅)₅/Ti(OC₂H₅)₄.

33. The method of forming a transistor as claimed in claim 29, further comprising the step of heat-treating the dielectric layer in an oxygen ambient.

34. A method of forming an atomic layer of a material on a substrate, comprising:

introducing a first precursor of the material to the substrate such that a first portion of the first precursor is chemisorbed onto the substrate and a second portion of the first precursor is not chemisorbed onto the substrate;

purging at least some of the second portion of the first precursor that is not chemisorbed onto the substrate;

introducing a second precursor of the material to the substrate such that a first portion of the second precursor is chemisorbed onto the substrate and reacts with the first portion of the first precursor that is chemisorbed onto the substrate to form the atomic layer of the material, and a second portion of the second precursor is not chemisorbed onto the substrate; and

purging at least some of the second portion of the second precursor that is not chemisorbed onto the substrate.

35. A method according to claim 34 wherein the first precursor and/or the second precursor comprises a mixture of first precursors of the material and/or a mixture of second precursors of the material.

36. A method according to claim 34 wherein the introducing a first precursor, purging at least some of the second portion of the first precursor, introducing a second precursor and purging at least some of the second portion of the second precursor are repeatedly performed in sequence to form a plurality of atomic layers of the material on the substrate.

37. A method according to claim 34:

wherein the introducing a first precursor comprises introducing a first precursor of the material to the substrate in a purge gas flow;

wherein the purging at least some of the second portion of the first precursor comprises maintaining the purge gas flow while discontinuing the introducing the first precursor;

wherein the introducing a second precursor comprises introducing a second precursor of the material to the substrate in the purge gas flow; and

wherein the purging at least some of the second portion of the second precursor comprises maintaining the purge gas flow while discontinuing the introducing the second precursor.

38. A method according to claim 34 wherein the first precursor comprises titanium and tantalum, wherein the second precursor comprises oxygen and wherein the material comprises titanium tantalum oxide.

39. A method according to claim 34 wherein the introducing a first precursor of the material is preceded by forming a first capacitor electrode on the substrate;

wherein the introducing a first precursor of the material comprises introducing the first precursor of the material on the first capacitor electrode and wherein the purging at least some of the second portion of the second precursor is followed by forming a second capacitor electrode on the material.

40. A method according to claim 34 wherein the purging at least some of the second portion of the second precursor is followed by forming a gate electrode of a field effect transistor on the material.

41. A method of forming an atomic layer of a material on a substrate, comprising:

introducing a first precursor of the material onto the substrate in a purge gas flow;

then

discontinuing the introducing the first precursor while maintaining the purge gas flow;

then

introducing a second precursor of the material onto the substrate in the purge gas flow; and

then

discontinuing the introducing the second precursor while maintaining the purge gas flow.

42. A method according to claim 41 wherein the first precursor and/or the second precursor comprises a mixture of first precursors of the material and/or a mixture of second precursors of the material.

43. A method according to claim 41 wherein the introducing a first precursor, discontinuing the introducing the first precursor, introducing a second precursor and discontinuing the introducing the second precursor are repeatedly performed in sequence to form a plurality of atomic layers of the material on the substrate.

44. A method according to claim 41 wherein the first precursor comprises titanium and tantalum, wherein the second precursor comprises oxygen and wherein the material comprises titanium tantalum oxide.

45. A method according to claim 41 wherein the introducing a first precursor of the material is preceded by forming a first capacitor electrode on the substrate;

wherein the introducing a first precursor of the material comprises introducing the first precursor of the material on the first capacitor electrode and wherein the discontinuing the introducing the second precursor is followed by forming a second capacitor electrode on the material.

46. A method according to claim 41 wherein the discontinuing the introducing the second precursor is followed by forming a gate electrode of a field effect transistor on the material.