Method for selective removal of high-k material

• US 7,132,370 B2
• Filed: 03/09/2004
• Issued: 11/07/2006
• Est. Priority Date: 08/01/2003
• Status: Active Grant

• Current Assignee: Interuniversitair Micro-Electronica Centrum VZW (IMEC International)
• Original Assignee: Interuniversitair Micro-Electronica Centrum VZW (IMEC International)
• Inventors: Paraschiv, Vasile, Claes, Martine
• Primary Examiner(s): Vinh, Lan
• Application Number:
  US10/797,888
• Publication Number:
  US 20050115925A1
• Time in Patent Office: 973 Days
• Field of Search: 438/745, 438/750, 438/752, 438/754, 438/756, 252/791, 252/79.2, 216/103, 216/104
• US Class Current: 438/756
• CPC Class Codes: H01L 21/31111 by chemical means
• CPC Class Codes: H01L 29/66477 with an insulated gate, i.e. MISFET

Abstract

The present invention relates to a method for selectively removing a high-k material comprising providing a high-k material on a semiconductor substrate, and contacting the high-k material with a solution comprising HF, an organic compound, and an inorganic acid.

Claims

1. A method for selective removal of a high-k material from a substrate, the method comprising:

providing a high-k material on a semiconductor substrate; and

contacting the high-k material with a solution comprising HF at a concentration of from about 0.05 M, ethanol at a concentration of about 80%, and HCl at a concentration of about 20%, whereby the high-k material is selectively removed from the substrate.

2. The method according to claim 1, wherein the high-k material has a dielectric constant of greater than or equal to about 7.

3. The method according to claim 1, wherein the high-k material is selected from the group consisting of ZrO₂, Al₂O₃, HfO₂, Zr_1-xAl_xO_y, HfSiO_x, HfAlO_x, HfSiO_xN, and combinations thereof, wherein x is an integer, and wherein y is an integer.

4. The method according to claim 1, wherein a wettability of the ethanol for the high-k material is higher than a wettability of the ethanol for silicon oxide.

5. The method according to claim 1, wherein a temperature of the solution is from about 20°

C. to about 80°

C.

6. The method according to claim 1, wherein a temperature of the solution is about 40°

C.

7. The method according to claim 1, wherein the solution further comprises a surfactant.

8. The method according to claim 1, wherein the solution has a pH of from about −

0.5 to about 2.

9. A method for selective removal of a high-k material from a semiconductor substrate comprising:

providing a high-k material on a semiconductor substrate;

subjecting the high-k material to damaging, whereby a damaged high-k material is obtained; and

thereafter

contacting the damaged high-k material with a solution comprising HF at a concentration of from about 0.05 M, ethanol at a concentration of about 80%, and HCl at a concentration of about 20%, whereby the high-k material is selectively removed from the substrate.

10. The method according to claim 9, wherein the high-k material has a dielectric constant of greater than or equal to about 7.

11. The method according to claim 9, wherein the high-k material is selected from the group consisting of ZrO₂, Al₂O₃, HfO₂, Zr_1-xAl_xO_y, HfSiO_x, HfAlO_x, HfSiO_xN, and combinations thereof, wherein x is an integer, and wherein y is an integer.

12. The method according to claim 9, wherein a wettability of the ethanol for the high-k material is higher than a wettability of the ethanol for silicon oxide.

13. The method according to claim 9, wherein a temperature of the solution is from about 20°

C. to about 80°

C.

14. The method according to claim 9, wherein a temperature of the solution is about 40°

C.

15. The method according to claim 9, wherein the solution further comprises a surfactant.

16. The method according to claim 9, wherein the solution has a pH of from about −

0.5 to about 2.

17. The method according to claim 9, wherein the damaging comprises chemical damaging.

18. The method according to claim 9, wherein the damaging comprises physical damaging.

19. A method for selective removal of a high-k material from a substrate, the method comprising:

providing a high-k material on a semiconductor substrate; and

contacting the high-k material with a solution comprising HF at a concentration of from about 0.04 M to about 0.06 M, an alcohol at a concentration greater than or equal to about 50%, and HCl at a concentration of from about 10% to about 30%, whereby the high-k material is selectively removed from the substrate.

20. The method according to claim 19, wherein the high-k material has a dielectric constant of greater than or equal to about 7.

21. The method according to claim 19, wherein the high-k material is selected from the group consisting of ZrO₂, Al₂O₃, HfO₂, Zr_1-xAl_xO_y, HfSiO_x, HfAlO_x, HfSiO_xN, and combinations thereof, wherein x is an integer, and wherein y is an integer.

22. The method according to claim 19, wherein a concentration of HF in the solution is about 0.05 M.

23. The method according to claim 19, wherein a concentration of the HCl in the solution is about 20%.

24. The method according to claim 19, wherein a wettability of the alcohol for the high-k material is higher than a wettability of the alcohol for silicon oxide.

25. The method according to claim 19, wherein the alcohol is selected from the group consisting of ethanol, isopropylalcohol, ethyleneglycol, and mixtures thereof.

26. The method according to claim 19, wherein a concentration of the alcohol in the solution is from about 60% to about 90%.

27. The method according to claim 19, wherein a concentration of the alcohol in the solution is about 80%.

28. The method according to claim 19, wherein a temperature of the solution is from about 20°

C. to about 80°

C.

29. The method according to claim 19, wherein a temperature of the solution is about 40°

C.

30. The method according to claim 19, wherein the alcohol is ethanol.

31. The method according to claim 19, wherein the solution further comprises a surfactant.

32. The method according to claim 19, wherein the solution has a pH of from about −

0.5 to about 2.

33. A method for selective removal of a high-k material from a semiconductor substrate comprising:

providing a high-k material on a semiconductor substrate;

subjecting the high-k material to damaging, whereby a damaged high-k material is obtained; and

thereafter

contacting the damaged high-k material with a solution comprising HF at a concentration of from about 0.04 M to about 0.06 M, an alcohol at a concentration greater than or equal to about 50%, and HCl at a concentration of from about 10% to about 30%, whereby the high-k material is selectively removed from the substrate.

34. The method according to claim 33, wherein the high-k material has a dielectric constant of greater than or equal to about 7.

35. The method according to claim 33, wherein the high-k material is selected from the group consisting of ZrO₂, Al₂O₃, HfO₂, Zr_1-xAl_xO_y, HfSiO_x, HfAlO_x, HfSiO_xN, and combinations thereof, wherein x is an integer, and wherein y is an integer.

36. The method according to claim 33, wherein a concentration of HF in the solution is about 0.05 M.

37. The method according to claim 33, wherein a concentration of the HCl in the solution is about 20%.

38. The method according to claim 33, wherein a wettability of the alcohol for the high-k material is higher than a wettability of the alcohol for silicon oxide.

39. The method according to claim 33, wherein the organic compound is selected from the group consisting of ethanol, isopropylalcohol, ethyleneglycol, and mixtures thereof.

40. The method according to claim 33, wherein a concentration of the alcohol in the solution is from about 60% to about 90%.

41. The method according to claim 33, wherein a concentration of the alcohol in the solution is about 80%.

42. The method according to claim 33, wherein a temperature of the solution is from about 20°

C. to about 80°

C.

43. The method according to claim 33, wherein a temperature of the solution is about 40°

C.

44. The method according to claim 33, wherein the alcohol is ethanol.

45. The method according to claim 33, wherein the solution further comprises a surfactant.

46. The method according to claim 33, wherein the solution has a pH of from about −

0.5 to about 2.

47. The method according to claim 33, wherein the damaging comprises chemical damaging.

48. The method according to claim 33, wherein the damaging comprises physical damaging.