Element Storage Layer in Integrated Circuits

• US 20040057193A1
• Filed: 06/13/2003
• Published: 03/25/2004
• Est. Priority Date: 09/19/2002
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Bum K.I. Moon, Gerhard Beitel
• Inventors: Moon, Bum Ki, Beitel, Gerhard
• Granted Patent: US 6,891,713 B2
• Time in Patent Office: Days
• US Class Current: 361/313
• CPC Class Codes: H01L 21/76895 Local interconnects; Local pads, as exemplified by patent document EP0896365
• CPC Class Codes: H01L 28/60 Electrodes
• CPC Class Codes: H10B 53/00 Ferroelectric RAM [FeRAM] devices comprising ferroelectric memory capacitors
• CPC Class Codes: H10B 53/30 characterised by the memory core region

Abstract

Reduced degradation to capacitor properties is disclosed. A hydrogen storage layer is provided over at least a portion a top capacitor electrode. The hydrogen storage layer absorbs and stores hydrogen, preventing hydrogen from diffusing to the capacitor. The hydrogen storage layer comprises, for example, lanthium nitride, titanium zirconium nitride, amorphous sm—co, nanostructured carbon, or a combination thereof.

Claims

1. a capacitor structure comprising:

top and bottom electrodes;

a capacitor dielectric disposed between top and bottom electrodes; and

an element storage layer covering and electrically coupled to the top electrode, the element storage layer absorbing or storing element harmful to the capacitor.

2. The capacitor structure of claim 1 wherein the capacitor dielectric comprises a ferroelectric material to form a ferroelectric capacitor of a memory cell, a plurality of memory cells interconnected to form a memory array of an IC.

3. The capacitor structure of claim 1 is a capacitor structure of a memory cell, a plurality of memory cells interconnected to form a memory array of an IC.

4. The capacitor structure of claim 1 wherein the element storage layer covers the top electrode completely, partially to sufficiently accommodate a contact electrically coupled to the top electrode or overlaps the top electrode to partially or completely offset the contact electrically coupled to the top electrode.

5. The capacitor structure of claim 4 wherein the element storage layer absorbs or stores hydrogen.

6. The capacitor structure of claim 5 wherein the element storage layer comprises a material selected from lanthium nitride, titanium zirconium nitride, amorphous sm—

co, nanostructured carbon, or a combination thereof.

7. The capacitor structure of claim 5 wherein the element storage layer comprises a plurality of sublayers which absorb or store hydrogen or a combination of sublayers which do and do not absorb or store hydrogen.

8. The capacitor structure of claim 7 wherein the sublayers which absorb hydrogen comprise a material selected from lanthium nitride, titanium zirconium nitride, amorphous sm-co, nanostructured carbon, or a combination thereof.

9. The capacitor structure of claim 4 further comprises a barrier layer protecting at least sides of the capacitor.

10. The capacitor structure of claim 9 wherein the element storage layer absorbs or stores hydrogen.

11. The capacitor structure of claim 10 wherein the element storage layer comprises a material selected from lanthium nitride, titanium zirconium nitride, amorphous sm—

co, nanostructured carbon, or a combination thereof.

12. The capacitor structure of claim 10 wherein the element storage layer comprises a plurality of sublayers which absorb or store hydrogen or a combination of sublayers which do and do not absorb or store hydrogen.

13. The capacitor structure of claim 12 wherein the sublayers which absorb hydrogen comprise a material selected from lanthium nitride, titanium zirconium nitride, amorphous sm-co, nanostructured carbon, or a combination thereof.

14. The capacitor structure of claim 9 wherein the barrier layer comprises a material which prevents the diffusion of hydrogen.

15. The capacitor structure of claim 14 wherein the element storage layer absorbs or stores hydrogen.

16. The capacitor structure of claim 15 wherein the element storage layer comprises a material selected from lanthium nitride, titanium zirconium nitride, amorphous sm—

co, nanostructured carbon, or a combination thereof.

17. The capacitor structure of claim 15 wherein the element storage layer comprises a plurality of sublayers which absorb or store hydrogen or a combination of sublayers which do and do not absorb or store hydrogen.

18. The capacitor structure of claim 17 wherein the sublayers which absorb hydrogen comprise a material selected from lanthium nitride, titanium zirconium nitride, amorphous sm—

co, nanostructured carbon, or a combination thereof.

19. The capacitor structure of claim 4 further comprises a barrier layer protecting at least sides of the capacitor, surface of the element storage layer and surface of top electrode if the element storage layer does not cover the surface of the top electrode completely.

20. The capacitor structure of claim 19 wherein the element storage layer absorbs or stores hydrogen.

21. The capacitor structure of claim 20 wherein the element storage layer comprises a material selected from lanthium nitride, titanium zirconium nitride, amorphous sm—

co, nanostructured carbon, or a combination thereof.

22. The capacitor structure of claim 20 wherein the element storage layer comprises a plurality of sublayers which absorb or store hydrogen or a combination of sublayers which do and do not absorb or store hydrogen.

23. The capacitor structure of claim 22 wherein the sublayers which absorb hydrogen comprise a material selected from lanthium nitride, titanium zirconium nitride, amorphous sm-co, nanostructured carbon, or a combination thereof.

24. The capacitor structure of claim 19 wherein the barrier layer comprises a material which prevents the diffusion of hydrogen.

25. The capacitor structure of claim 24 wherein the element storage layer absorbs or stores hydrogen.

26. The capacitor structure of claim 25 wherein the element storage layer comprises a material selected from lanthium nitride, titanium zirconium nitride, amorphous sm—

co, nanostructured carbon, or a combination thereof.

27. The capacitor structure of claim 25 wherein the element storage layer comprises a plurality of sublayers which absorb or store hydrogen or a combination of sublayers which do and do not absorb or store hydrogen.

28. The capacitor structure of claim 27 wherein the sublayers which absorb hydrogen comprise a material selected from lanthium nitride, titanium zirconium nitride, amorphous sm-co, nanostructured carbon, or a combination thereof.

29. The capacitor structure of claim 1 wherein the element storage layer absorbs or stores hydrogen.

30. The capacitor structure of claim 29 wherein the element storage layer comprises a material selected from lanthium nitride, titanium zirconium nitride, amorphous sm—

co, nanostructured carbon, or a combination thereof.

31. The capacitor structure of claim 29 wherein the element storage layer comprises a plurality of sublayers which absorb or store hydrogen or a combination of sublayers which do and do not absorb or store hydrogen.

32. The capacitor structure of claim 31 wherein the sublayers which absorb hydrogen comprise a material selected from lanthium nitride, titanium zirconium nitride, amorphous sm-co, nanostructured carbon, or a combination thereof.

33. A method of forming a capacitor comprising:

providing a substrate prepared with a capacitor having top and bottom electrodes and a capacitor dielectric disposed between the electrodes; and

forming an element storage layer covering at least a portion of the top electrode sufficient to accommodate a contact for coupling to the top capacitor electrode, the element storage layer comprises a material which absorbs or stores elements harmful to the capacitor.