Methods of forming capacitor structures, and capacitor structures

• US 20020090777A1
• Filed: 01/05/2001
• Published: 07/11/2002
• Est. Priority Date: 01/05/2001
• Status: Active Grant

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Ahn, Kie Y., Forbes, Leonard, Eldridge, Jerome Michael
• Granted Patent: US 7,192,827 B2
• Time in Patent Office: Days
• US Class Current: 438/238
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02244 of a metallic layer
• CPC Class Codes: H01L 21/02247 formation by nitridation, e.g. nitridation of the substrate
• CPC Class Codes: H01L 21/02252 formation by plasma treatment, e.g. plasma oxidation of the substrate after treatment of an insulating film by plasma H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/3144 on silicon
• 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 21/318 composed of nitrides
• CPC Class Codes: H01L 28/40 Capacitors

Abstract

The invention includes a method of forming a capacitor structure. A first electrical node is formed, and a layer of metallic aluminum is formed over the first electrical node. Subsequently, an entirety of the metallic aluminum within the layer is transformed into one or more of AlN, AlON, and AlO, with the transformed layer being a dielectric material over the first electrical node. A second electrical node is then formed over the dielectric material. The first electrical node, second electrical node and dielectric material together define at least a portion of the capacitor structure. The invention also pertAlNs to a capacitor structure which includes a first electrical node, a second electrical node, and a dielectric material between the first and second electrical nodes. The dielectric material consists essentially of aluminum, oxygen and nitrogen.

Claims

1. A method of forming a capacitor structure, comprising:

forming a first electrical node;

forming a layer of metallic aluminum over the first electrical node;

transforming at least some the metallic aluminum within the layer of metallic aluminum to AlN or AlON;

wherein the listed compounds are described in terms of chemical constituents rather than stoichiometry;

the transformed layer being a dielectric material over the first electrical node; and

forming a second electrical node that is electrically separated from the first electrical node by at least the dielectric material;

the first electrical node, second electrical node and dielectric material together defining at least a portion of a capacitor structure.

2. The method of claim 1 wherein the at least some of the layer is converted to AlN.

3. The method of claim 1 wherein the at least some of the layer is converted to AlON.

4. A method of forming a capacitor structure, comprising:

forming a first electrical node;

forming a layer of metallic aluminum over the first electrical node;

transforming an entirety of the metallic aluminum within the layer of metallic aluminum to AlN, AlON, or AlO;

wherein the listed compounds are described in terms of chemical constituents rather than stoichiometry;

the transformed layer being a dielectric material over the first electrical node; and

forming a second electrical node that is electrically separated from the first electrical node by at least the dielectric material;

the first electrical node, second electrical node and dielectric material together defining at least a portion of a capacitor structure.

5. The method of claim 4 wherein the transforming occurs at a temperature which does not exceed 200°

C.

6. The method of claim 4 wherein the transforming comprises transforming an entirety of the metallic aluminum within the layer to AlN.

7. The method of claim 4 wherein the transforming comprises transforming an entirety of the metallic aluminum within the layer to AlN to form a resulting AlN layer;

the resulting AlN layer having a thickness of from about 20 Å

to about 40 Å

.

8. The method of claim 4 wherein the transforming comprises transforming an entirety of the metallic aluminum within the layer to AlN to form a resulting AlN layer;

and further comprising;

forming a second layer of metallic aluminum on the resulting AlN layer; and

transforming an entirety of the second layer of metallic aluminum to AlON to form a resulting AlON layer.

9. The method of claim 8 wherein the resulting layer of AlN has a thickness of from about 10 Å

to about 20 Å

, and wherein the resulting layer of AlON has a thickness of from about 10 Å

to about 20 Å

.

10. The method of claim 4 wherein:

the first electrical node comprises conductively doped silicon;

the layer of metallic aluminum is formed on the first electrical node; and

the transforming comprises transforming an entirety of the metallic aluminum within the layer to AlN to form a resulting AlN layer;

the resulting AlN layer having a thickness of from about 20 Å

to about 40 Å

.

11. The method of claim 4 further comprising forming a layer of silicon dioxide between the first electrical node and the layer of metallic aluminum;

and wherein;

the first electrical node comprises conductively doped silicon;

the layer of silicon dioxide is formed on the first electrical node;

the layer of metallic aluminum is formed on the layer of silicon dioxide; and

the transforming comprises transforming an entirety of the metallic aluminum within the layer to AlN to form a resulting AlN layer.

12. The method of claim 11 wherein the resulting AlN layer has a thickness of from about 20 Å

to about 40 Å

.

13. The method of claim 11 wherein the layer of silicon dioxide has a thickness of greater than 0 Å

and less than or equal to about 15 Å

.

14. The method of claim 11 further comprising:

forming a second layer of metallic aluminum on the resulting AlN layer; and

transforming an entirety of the second layer of metallic aluminum to AlO to form a resulting AlO layer.

15. The method of claim 14 wherein the resulting layer of AlN has a thickness of from about 5 Å

to about 15 Å

;

wherein the resulting AlO layer has a thickness of from about 5 Å

to about 15 Å

; and

wherein the layer of silicon dioxide has a thickness of from about 5 Å

to about 15 Å

.

16. The method of claim 4 wherein the transforming comprises transforming an entirety of the metallic aluminum within the layer to AlON.

17. The method of claim 4 wherein the transforming comprises transforming an entirety of the metallic aluminum within the layer to AlON to form a resulting AlON layer;

the resulting AlON layer having a thickness of from about 20 Å

to about 40 Å

.

18. The method of claim 4 wherein:

the first electrical node comprises conductively doped silicon;

the layer of metallic aluminum is formed on the first electrical node; and

the transforming comprises transforming an entirety of the metallic aluminum within the layer to AlON to form a resulting AlON layer;

the resulting AlON layer having a thickness of from about 20 Å

to about 40 Å

.

19. The method of claim 4 further comprising forming a layer of silicon dioxide between the first electrical node and the layer of metallic aluminum;

and wherein;

the first electrical node comprises conductively doped silicon;

the layer of silicon dioxide is on the first electrical node;

the layer of metallic aluminum is on the layer of silicon dioxide; and

the transforming comprises transforming an entirety of the metallic aluminum within the layer to AlON to form a resulting AlON layer.

20. The method of claim 19 wherein the layer of silicon dioxide is formed before forming the layer of metallic aluminum.

21. The method of claim 19 wherein the resulting AlON layer has a thickness of from about 10 Å

to about 20 Å

.

22. The method of claim 19 wherein the layer of silicon dioxide is formed after forming the layer of metallic aluminum and during the transforming of the layer of metallic aluminum.

23. The method of claim 19 wherein the layer of silicon dioxide has a thickness of greater than 0 Å

and less than or equal to about 15 Å

.

24. The method of claim 4 wherein the transforming comprises transforming an entirety of the metallic aluminum within the layer to AlO.

25. The method of claim 4 wherein the transforming comprises transforming an entirety of the metallic aluminum within the layer to AlO to form a resulting AlO layer;

the resulting AlO layer having a thickness of from about 10 Å

to about 20 Å

.

26. The method of claim 4 further comprising providing a transistor adjacent the capacitor structure;

the transistor and a capacitor structure together defining a DRAM cell comprising the transistor and the capacitor structure.

28. The capacitor structure of claim 27 wherein the dielectric material comprises a thickness of from about 20 Å

to about 40 Å

.

29. The capacitor structure of claim 27 wherein the dielectric material is on the first electrical node.

30. The capacitor structure of claim 27 wherein the dielectric material is on the first electrical node, and wherein the first electrical node comprises silicon.

31. The capacitor structure of claim 27 wherein the dielectric material is on the first electrical node, and wherein the second electrical node is on the dielectric material.

32. The capacitor structure of claim 27 wherein the dielectric material is on the first electrical node, wherein the second electrical node is on the dielectric material, and wherein the first and second electrical nodes comprise silicon.

33. The capacitor structure of claim 27 wherein the dielectric material is separated from the first electrical node by a layer of silicon dioxide.

34. The capacitor structure of claim 33 wherein the dielectric material comprises a thickness of from about 10 Å

to about 20 Å

; and

wherein the silicon dioxide comprises a thickness of from about 5 Å

to about 15 Å

.

27. A capacitor structure, comprising:

a first electrical node;

a second electrical node; and

a capacitor dielectric region operatively positioned between the first and second electrical nodes, the dielectric region comprising a dielectric material which consists essentially of aluminum, oxygen and nitrogen;

.