Method for forming refractory metal oxide layers with tetramethyldisiloxane

• US 6,784,049 B2
• Filed: 08/28/2002
• Issued: 08/31/2004
• Est. Priority Date: 08/28/2002
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Vaartstra, Brian A.
• Primary Examiner(s): Niebling, John F.
• Assistant Examiner(s): Kennedy, Jennifer M.
• Application Number:
  US10/229,653
• Publication Number:
  US 20040043633A1
• Time in Patent Office: 734 Days
• Field of Search: 438/3, 438/240, 438/253, 438/396, 257/310
• US Class Current: 438/240
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• 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 21/02205 the layer being characterised by the precursor material for deposition
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• 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 28/40 Capacitors

Abstract

A method of forming (and apparatus for forming) refractory metal oxide layers, such as tantalum pentoxide layers, on substrates by using vapor deposition processes with refractory metal precursor compounds and ethers.

Claims

1. A method of forming a layer on a substrate, the method comprising:

providing a substrate;

providing a vapor comprising one or more refractory metal precursor compounds of the formula MY_n (Formula I), wherein M is a refractory metal, each Y is independently a halogen atom, and n is an integer selected to match the valence of the metal M;

providing a vapor comprising one or more ethers of the formula R¹—

O—

R², wherein R¹ and R² are each independently organic groups, and with the proviso that at least one of the one or more ethers comprises tetramethyldisiloxane; and

directing the vapors comprising the one or more refractory metal precursor compounds and the one or more ethers to the substrate to form a refractory metal oxide layer on one or more surfaces of the substrate.

2. The method of claim 1 wherein Y is independently selected from the group consisting of F, Cl, I, and combinations thereof.

3. The method claim 2 wherein each Y is independently a fluorine atom.

4. The method of claim 3 wherein M is tantalum and n is 5.

5. The method of claim 1 wherein M is tantalum and n is 5.

6. The method of claim 1 wherein the substrate comprises a material selected from the group consisting of silicon, platinum, titanium nitride, tantalum nitride, tantalum-silicon-nitride.

7. The method of claim 1 wherein the formed layer has a thickness of about 10 Å

to about 100 Å

.

8. The method of claim 1 wherein the formed layer is a Ta₂O₅ layer.

9. The method of claim 8 wherein the Ta₂O₅ layer comprises a crystalline hexagonal phase.

10. The method of claim 1 wherein the formed layer is a dielectric layer.

11. The method of claim 1 wherein providing the vapors and directing the vapors is accomplished using a chemical vapor deposition process.

12. The method of claim 11 wherein the temperature of the substrate is about 100°

C. to about 600°

C.

13. The method of claim 1 wherein providing the vapors and directing the vapors is accomplished using an atomic layer deposition process comprising a plurality of deposition cycles.

14. The method of claim 13 wherein the temperature of the substrate is about 25°

C. to about 400°

C.

15. The method of claim 1 further comprising providing a vapor comprising one or more metal-containing precursor compounds having a formula different than Formula I and directing the vapor comprising the one or more compounds having a formula different than Formula I to the substrate.

16. A method of manufacturing a semiconductor structure, the method comprising:

providing a semiconductor substrate or substrate assembly;

providing a vapor comprising one or more refractory metal precursor compounds of the formula MY_n (Formula I), wherein M is a refractory metal, each Y is independently a halogen atom, and n is an integer selected to match the valence of the metal M;

providing a vapor comprising one or more ethers of the formula R¹—

O—

R², wherein R¹ and R² are each independently organic groups, and with the proviso that at least one of the one or more ethers comprises tetramethyldisiloxane; and

directing the vapors comprising the one or more refractory metal precursor compounds and the one or more ethers to the semiconductor substrate or substrate assembly to form a refractory metal oxide layer on one or more surfaces of the semiconductor substrate or substrate assembly.

17. The method of claim 16 wherein the semiconductor substrate or substrate assembly is a silicon wafer.

18. The method of claim 16 wherein Y is independently selected from the group consisting of F, CI, I, and combinations thereof.

19. The method of claim 18 wherein each Y is independently a flourine atom.

20. The method of claim 16 wherein M is tantalum and n is 5.

21. The method of claim 16 wherein providing the vapors and directing the vapors is accomplished using an atomic layer deposition process comprising a plurality of deposition cycles.

22. The method of claim 21 wherein the temperature of the semiconductor substrate or substrate assembly is about 25°

C. to about 400°

C.

23. The method of claim 21 wherein the semiconductor substrate or substrate assembly is in a deposition chamber having a pressure of about 10⁻

4 torr to about 1 torr.

24. The method of claim 21 wherein during the atomic layer deposition process, the refractory metal oxide layer is formed by alternately introducing the one or more vaporized precursor compounds and one or more vaporized ethers during each deposition cycle.

25. The method of claim 16 wherein the substrate comprises a material selected from the group consisting of silicon, platinum, titanium nitride, tantalum nitride, tantalum-silicon-nitride.

26. The method of claim 16 wherein the formed layer has a thickness of about 10 Å

to about 100 Å

.

27. The method of claim 16 wherein the formed layer is a Ta₂O₅ layer.

28. The method of claim 27 wherein the Ta₂O₅ layer comprises a crystalline hexagonal phase.

29. The method of claim 16 wherein the formed layer is a dielectric layer.

30. The method of claim 16 wherein providing the vapors and directing the vapors is accomplished using a chemical vapor deposition process.

31. The method of claim 30 wherein the temperature of the semiconductor substrate or substrate assembly is about 100°

C. to about 600°

C.

32. The method of claim 30 wherein the semiconductor substrate or substrate assembly is in a deposition chamber having a pressure of about 0.1 torr to about 10 torr.

33. The method of claim 16 further comprising providing a vapor comprising one or more metal-containing precursor compounds having a formula different than Formula I and directing the vapor comprising the one or more compounds having a formula different than Formula I to the semiconductor substrate or substrate assembly.

34. A method of manufacturing a memory device, the method comprising:

providing a substrate having a first electrode thereon;

providing a vapor comprising one or more refractory metal precursor compounds of the formula MY_n (Formula I) wherein M is a refractory metal, each Y is independently a halogen atom, and n is an integer selected to match the valence of the metal M;

providing a vapor comprising one or more ethers of the formula R¹—

O—

R², wherein R¹ and R² are each independently organic groups, and with the proviso that at least one of the one or more ethers comprises tetramethyldisiloxane;

directing the vapors comprising the one or more refractory metal precursor compounds and the one or more ethers to the substrate to form a refractory metal oxide dielectric layer on the first electrode of the substrate; and

forming a second electrode on the dielectric layer.

35. The method of claim 34 wherein the substrate is a semiconductor substrate or substrate assembly.

36. The method of claim 34 wherein formed layer has a thickness of about 10 Å

to about 100 Å

.

37. The method of claim 34 wherein the formed layer is a Ta₂O₅ layer.

38. The method of claim 34 wherein the Ta₂O₅ layer comprises a crystalline hexagonal phase.

39. The method of claim 34 further comprising providing an inert carrier gas for directing the one or more vaporized refractory metal precursor compounds and the one or more vaporized ethers to the substrate.

40. The method of claim 39 wherein the inert carrier gas is selected from the group consisting of nitrogen, helium, and argon.

41. The method of claim 34 wherein providing the vapors and directing the vapors is accomplished using an atomic layer deposition process comprising a plurality of deposition cycles.

42. The method of claim 34 wherein providing the vapors and directing the vapors is accomplished using a chemical vapor deposition process.

43. The method of claim 34 further comprising providing a vapor comprising one or more metal-containing precursor compounds having a formula different than Formula I and directing the vapor comprising the one or more compounds having a formula different than Formula I to the substrate.