METHODS OF FORMING INTEGRATED CIRCUIT ELECTRODES AND CAPACITORS BY WRINKLING A LAYER THAT INCLUDES A HIGH PERCENTAGE OF IMPURITIES

• US 20060263977A1
• Filed: 08/03/2006
• Published: 11/23/2006
• Est. Priority Date: 07/24/2001
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Won, Seok-jun, Chung, Jung-hee, Chung, Suk-jin, Joo, Jae-hyun, Kim, Jin-yong, Kim, Wan-don
• Granted Patent: US 7,700,454 B2
• Time in Patent Office: Days
• US Class Current: 438/253
• CPC Class Codes: H01L 28/84 being a rough surface, e.g. using hemispherical grains
• CPC Class Codes: H10B 12/03 Making the capacitor or connections thereto

Abstract

A method of fabricating a uniformly wrinkled capacitor lower electrode without the need to perform a high-temperature heat treatment and a method of fabricating a capacitor including the uniformly wrinkled capacitor lower electrode are provided. A first conductive layer is formed. Then, a second conductive layer including about 20% to about 50% of impurities is formed on the first conductive layer. Next, at least some of the impurities are exhausted from the second conductive layer by heat treating the second conductive layer. A surface of the second conductive layer is wrinkled due to the exhaustion of the impurities from the second conductive layer. A dielectric layer and an upper capacitor electrode may then be formed.

Claims

1. A method of fabricating an electrode, comprising:

forming a first conductive layer;

forming a second conductive layer to include about 20% to about 50% of impurities, on the first conductive layer; and

exhausting at least some of the impurities from the second conductive layer by heat treating the second conductive layer, to wrinkle a surface of the second conductive layer due to the exhaustion of at least some of the impurities from the second conductive layer.

2. The method of claim 1, wherein the impurities contained in the second conductive layer comprise carbon.

3. The method of claim 1, wherein the forming of the second conductive layer comprises chemical vapor depositing the second conductive layer at about 100°

C. to about 300°

C.

4. The method of claim 1, wherein the forming of the second conductive layer comprises supplying only a metal source.

5. The method of claim 4, wherein the forming of the second conductive layer comprises atomic layer depositing the second conductive layer.

6. The method of claim 1, wherein the forming of the second conductive layer comprises supplying a metal source, an oxygen source, and a tetrahydrofuran solvent.

7. The method of claim 6, wherein the forming of the second conductive layer comprises atomic layer depositing the second conductive layer.

8. The method of claim 1, wherein the first conductive layer has less than about 10% impurity content.

9. The method of claim 1, wherein the heat treating is conducted under a reducing atmosphere including H₂ and/or N₂ gas.

10. The method of claim 1, wherein the heat treating is conducted under a vacuum atmosphere of about 0.01 mTorr to about 10 mTorr.

11. The method of claim 1, wherein the heat treating is conducted at about 300°

C. to about 500°

C.

12. The method of claim 8, wherein the first conductive layer has between about 0.01% to about 10% impurity content.

13. The method of claim 1, wherein the electrode is a capacitor lower electrode.

14. The method of claim 1, wherein the exhausting of at least some of the impurities comprises exhausting at least some of the impurities from the second conductive layer so that less than about 10% impurities remain in the second conductive layer.

15. The method of claim 1 wherein the exhausting of at least some of the impurities comprises exhausting at least about 50% of the impurities in the second conductive layer.

16. A method of fabricating a capacitor, comprising:

forming a first lower electrode layer on a substrate;

forming a second lower electrode layer to include about 20% to about 50% of carbon, on the first lower electrode layer;

forming a lower electrode having a wrinkled surface by exhausting at least some of the carbon from the second lower electrode layer;

forming a dielectric film on the wrinkled surface of the lower electrode; and

forming an upper electrode on the dielectric film.

17. The method of claim 16, wherein the forming of the second lower electrode layer comprises chemical vapor depositing the second lower electrode layer at about 100°

C. to about 300°

C.

18. The method of claim 16, wherein the forming of the second lower electrode layer comprises atomic layer depositing the second lower electrode layer by supplying a metal source and purging the metal source.

19. The method of claim 16, wherein the forming of the second lower electrode layer comprises:

supplying a metal source to a surface of the first lower electrode layer;

purging at least some atoms of the metal source that are not chemically adsorbed to the first lower electrode;

supplying an oxygen gas to the other metal atoms that are chemically adsorbed to the first lower electrode;

purging at least some atoms of the oxygen source that are not chemically adsorbed to the metal atoms;

supplying a tetrahydrofuran solvent to at least some of the other chemically adsorbed atoms of the oxygen gas; and

purging at least some of the tetrahydrofuran solvent.

20. The method of claim 16, wherein the first lower electrode layer has an impurity content of less than about 10% so that the first lower electrode layer does not substantially decrease in size by heat treatment.

21. The method of claim 16, wherein the exhausting of at least some of the carbon from the second lower electrode layer comprises heat treating the second lower electrode layer at about 300°

C. to about 500°

C. under a reducing atmosphere including H₂ and/or N₂ gas.

22. The method of claim 16, wherein the exhausting of at least some of the carbon from the second lower electrode layer comprises heat treating the second lower electrode layer at about 300°

C. to about 500°

C. under a vacuum atmosphere of about 0.01 mTorr to about 10 mTorr.

23. The method of claim 16, wherein the first lower electrode layer, the second lower electrode layer, and/or the upper electrode comprises a noble metal, a noble metal oxide, and/or a refractory material, and

wherein the noble metal comprises Pt, Ru, and/or IR, the noble metal oxide comprises RuOx, IrOx, SRO, BSRO, and/or LSCo, and the refractory material comprises Ti, TiN, W, WN, Ta, TaN, HfN, ZrN, TiAlN, TaSiN, TiSiN, and/or TaAlN.

24. The method of claim 16, wherein the exhausting of at least some of the carbon comprises exhausting at least some of the carbon from the second lower electrode layer so that less than about 10% carbon remains in the second lower electrode layer.

25. The method of claim 16, wherein the exhausting of at least some of the carbon comprises exhausting at least about 50% of the carbon.

26. A method of fabricating an integrated circuit electrode, comprising:

forming a conductive layer to include about 20% to about 50% of impurities, on an integrated circuit substrate; and

exhausting the at least some of the impurities from the conductive layer by heat treating the conductive layer to wrinkle a surface of the conductive layer due to the exhaustion of at least some of the impurities from the conductive layer.

27. The method of claim 26, wherein the impurities contained in the conductive layer comprise carbon.

28. The method of claim 26, wherein the forming of the conductive layer comprises chemical vapor depositing the second conductive layer at about 100°

C. to about 300°

C.

29. The method of claim 26, wherein the forming of the conductive layer comprises supplying only a metal source.

30. The method of claim 29, wherein the forming of the conductive layer comprises atomic layer depositing the second conductive layer.

31. The method of claim 26, wherein the forming of the conductive layer comprises supplying a metal source, an oxygen source, and a tetrahydrofuran solvent.

32. The method of claim 31, wherein the forming of the conductive layer comprises atomic layer depositing the conductive layer.

33. The method of claim 26, wherein the heat treating is conducted under a reducing atmosphere including H₂ and/or N₂ gas.

34. The method of claim 26, wherein the heat treating is conducted under a vacuum atmosphere of about 0.01 mTorr to about 10 mTorr.

35. The method of claim 26, wherein the heat treating is conducted at about 300°

C. to about 500°

C.

36. The method of claim 26, wherein the exhausting of at least some of the impurities comprises exhausting at least some of the impurities from the conductive layer so that less than about 10% impurities remain in the conductive layer.

37. The method of claim 26 wherein the exhausting of at least some of the impurities comprises exhausting at least about 50% of the impurities in the conductive layer.