Methods of forming capacitors having dielectric regions that include multiple metal oxide-comprising materials

• US 8,993,044 B2
• Filed: 07/16/2012
• Issued: 03/31/2015
• Est. Priority Date: 06/12/2009
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Krishnan, Rishikesh, Smythe, John, Bhat, Vishwanath, Rocklein, Noel, Srinivasan, Bhaskar, Hull, Jeff, Carlson, Chris
• Primary Examiner(s): Cleveland, Michael
• Assistant Examiner(s): TADAYYON ESLAMI, TABASSOM
• Application Number:
  US13/550,340
• Publication Number:
  US 20120282754A1
• Time in Patent Office: 988 Days
• Field of Search: 427/79, 427/80, 257/303, 257/306, 257/532, 438/240, 438/785, 438/396, 438/239, 361/311, 361/312, 361/313, 361/502
• US Class Current: 427/79
• CPC Class Codes: H01G 4/12 Ceramic dielectrics H01G4/085 takes precedence
• CPC Class Codes: H01G 4/1272 Semiconductive ceramic capacitors
• CPC Class Codes: H01G 4/33 Thin- or thick-film capacitors thin- or thick-film circuits H01L27/00; capacitors without a potential-jump or surface barrier specially adapted for integrated circuits, details thereof, multistep manufacturing processes therefor H01L28/40
• CPC Class Codes: H01L 28/40 Capacitors

Abstract

Capacitors and methods of forming capacitors are disclosed, and which include an inner conductive metal capacitor electrode and an outer conductive metal capacitor electrode. A capacitor dielectric region is received between the inner and the outer conductive metal capacitor electrodes and has a thickness no greater than 150 Angstroms. Various combinations of materials of thicknesses and relationships relative one another are disclosed which enables and results in the dielectric region having a dielectric constant k of at least 35 yet leakage current no greater than 1×10⁻⁷ amps/cm² at from −1.1V to +1.1V.

Claims

1. A method of forming a capacitor, comprising:

depositing inner conductive metal capacitor electrode material over a substrate;

forming a capacitor dielectric region outward of the inner conductive metal capacitor electrode material to a thickness no greater than 150 Angstroms, a dielectric constant k of at least 35, and leakage current no greater than 1×

10<sup>−

7</sup> amps/cm² at from −

1.1V to +1.1V;

the forming of the capacitor dielectric region comprising;

depositing an amorphous ZrO₂-comprising material to a thickness of from 30 Angstroms to 70 Angstroms outward of the inner conductive metal capacitor electrode material;

annealing the amorphous ZrO₂-comprising material having thickness of from 30 Angstroms to 70 Angstroms after its deposition to form crystalline ZrO₂-comprising material having a thickness of from 30 Angstroms to 70 Angstroms;

after the annealing of the amorphous ZrO₂-comprising material, depositing an Al₂O₃-comprising material outward of the crystalline ZrO₂-comprising material, the Al₂O₃-comprising material having a thickness of from 2 Angstroms to 16 Angstroms;

depositing an amorphous TiO₂-comprising material to a thickness no greater than 50 Angstroms outward of the Al₂O₃-comprising material; and

annealing the amorphous TiO₂-comprising material having thickness no greater than 50 Angstroms in the presence of oxygen after its deposition to form crystalline TiO₂-comprising material; and

after the annealing of the amorphous TiO₂-comprising material, depositing outer conductive metal capacitor electrode material outward of the crystalline TiO₂-comprising material.

2. The method of claim 1 comprising depositing an intervening Al₂O₃-comprising material outward of the inner conductive metal capacitor electrode material prior to the depositing of the amorphous ZrO₂-comprising material, the intervening Al₂O₃-comprising material having a thickness of from 2 Angstroms to 10 Angstroms, a sum of the thicknesses of the intervening Al₂O₃-comprising material, the crystalline ZrO₂-comprising material, and the Al₂O₃-comprising material deposited over the crystalline ZrO₂-comprising material totals no more than 70 Angstroms.

3. The method of claim 2 wherein the intervening Al₂O₃-comprising material has a thickness of from 2 Angstroms to 4 Angstroms.

4. The method of claim 2 wherein the intervening Al₂O₃-comprising material is in direct physical touching contact with the crystalline ZrO₂-comprising material.

5. The method of claim 2 comprising providing an Al_xZr_yO_z-comprising material between the intervening Al₂O₃-comprising material and the crystalline ZrO₂-comprising material, the intervening Al₂O₃-comprising material and the ZrO₂-comprising material being in direct physical touching contact with the Al_xZr_yO_z-comprising material.

6. The method of claim 1 wherein the annealing of the amorphous ZrO₂-comprising material is conducted in an inert atmosphere.

7. The method of claim 1 comprising forming the capacitor dielectric region to a thickness no greater than 100 Angstroms.

8. The method of claim 1 comprising forming the Al₂O₃-comprising material in direct physical touching contact with the crystalline ZrO₂-comprising material.

9. The method of claim 1 comprising providing an Al_xZr_yO_z-comprising material between the Al₂O₃-comprising material and the crystalline ZrO₂-comprising material, the Al₂O₃-comprising material and the ZrO₂-comprising material being in direct physical touching contact with the Al_xZr_yO_z-comprising material.

10. The method of claim 1 comprising forming the crystalline TiO₂-comprising material in direct physical touching contact with the Al₂O₃-comprising material.

11. The method of claim 1 comprising providing a Ti_xAl_yO_z-comprising material between the Al₂O₃-comprising material and the crystalline TiO₂-comprising material, the Al₂O₃-comprising material and the crystalline TiO₂-comprising material being in direct physical touching contact with the Ti_xAl_yO_z-comprising material.

12. The method of claim 1 comprising depositing another Al₂O₃-comprising material outward of the crystalline TiO₂-comprising material prior to the depositing of the outer conductive metal capacitor electrode material, the another Al₂O₃-comprising material being deposited to a thickness of from 2 Angstroms to 10 Angstroms.

13. The method of claim 12 comprising forming the another Al₂O₃-comprising material in direct physical touching contact with the crystalline TiO₂-comprising material.

14. The method of claim 12 comprising providing a Ti_xAl_yO_z-comprising material between the another Al₂O₃-comprising material and the crystalline TiO₂-comprising material, the another Al₂O₃-comprising material and the crystalline TiO₂-comprising material being in direct physical touching contact with the Ti_xAl_yO_z-comprising material.

15. The method of claim 12 comprising depositing an intervening Al₂O₃-comprising material outward of the inner conductive metal capacitor electrode material prior to the depositing of the amorphous ZrO₂-comprising material, the intervening Al₂O₃-comprising material having a thickness of from 2 Angstroms to 10 Angstroms, a sum of the thicknesses of the intervening Al₂O₃-comprising material, the crystalline ZrO₂-comprising material, and the Al₂O₃-comprising material deposited over the crystalline ZrO₂-comprising material totals no more than 70 Angstroms.

16. A method of forming a capacitor, comprising:

depositing inner conductive metal capacitor electrode material over a substrate;

forming a capacitor dielectric region outward of the inner conductive metal capacitor electrode material to a thickness no greater than 150 Angstroms, a dielectric constant k of at least 35, and leakage current no greater than 1×

10<sup>−

7</sup> amps/cm² at from −

1.1V to +1.1V;

the forming of the capacitor dielectric region comprising;

depositing an amorphous ZrO₂-comprising material to a thickness of from 30 Angstroms to 70 Angstroms outward of the inner conductive metal capacitor electrode material;

annealing the amorphous ZrO₂-comprising having thickness of from 30 Angstroms to 70 Angstroms after its deposition to form crystalline ZrO₂-comprising material having a thickness of from 30 Angstroms to 70 Angstroms;

after the annealing of the amorphous ZrO₂-comprising material, depositing an Al₂O₃-comprising material outward of the crystalline ZrO₂-comprising material, the Al₂O₃-comprising material having a thickness of from 2 Angstroms to 16 Angstroms; and

depositing an amorphous TiO₂-comprising material to a thickness greater than 50 Angstroms outward of the Al₂O₃-comprising material; and

depositing outer conductive metal capacitor electrode material outward of the TiO₂-comprising material at a temperature which transforms the amorphous TiO₂-comprising material to be crystalline during said depositing of outer conductive metal capacitor electrode material.

17. The method of claim 16 comprising depositing an intervening Al₂O₃-comprising material outward of the inner conductive metal capacitor electrode material prior to the depositing of the amorphous ZrO₂-comprising material, the intervening Al₂O₃-comprising material having a thickness of from 2 Angstroms to 10 Angstroms, a sum of the thicknesses of the intervening Al₂O₃-comprising material, the crystalline ZrO₂-comprising material, and the Al₂O₃-comprising material deposited over the crystalline ZrO₂-comprising material totals no more than 70 Angstroms.

18. The method of claim 16 comprising depositing another Al₂O₃-comprising material outward of the amorphous TiO₂-comprising material prior to the depositing of the outer conductive metal capacitor electrode material, the another Al₂O₃-comprising material being deposited to a thickness of from 2 Angstroms to 10 Angstroms.

19. The method of claim 18 comprising depositing an intervening Al₂O₃-comprising material outward of the inner conductive metal capacitor electrode material prior to the depositing of the amorphous ZrO₂-comprising material, the intervening Al₂O₃-comprising material having a thickness of from 2 Angstroms to 10 Angstroms, a sum of the thicknesses of the intervening Al₂O₃-comprising material, the crystalline ZrO₂-comprising material, and the Al₂O₃-comprising material deposited over the crystalline ZrO₂-comprising material totals no more than 70 Angstroms.

20. A method of forming a capacitor, comprising:

depositing inner conductive metal capacitor electrode material over a substrate;

forming a capacitor dielectric region outward of the inner conductive metal capacitor electrode material to a thickness no greater than 150 Angstroms, a dielectric constant k of at least 35, and leakage current no greater than 1×

10<sup>−

7</sup> amps/cm² at from −

1.1V to +1.1V;

the forming of the capacitor dielectric region comprising;

depositing an amorphous ZrO₂-comprising material to a thickness of from 30 Angstroms to 70 Angstroms outward of the inner conductive metal capacitor electrode material;

annealing the amorphous ZrO₂-comprising having thickness of from 30 Angstroms to 70 Angstroms after its deposition to form crystalline ZrO₂-comprising material having a thickness of from 30 Angstroms to 70 Angstroms;

after the annealing of the amorphous ZrO₂-comprising material, depositing an Al₂O₃-comprising material outward of the crystalline ZrO₂-comprising material, the Al₂O₃-comprising material having a thickness of from 2 Angstroms to 16 Angstroms; and

depositing an amorphous TiO₂-comprising material to a thickness greater than 50 Angstroms outward of the Al₂O₃-comprising material; and

depositing outer conductive metal capacitor electrode material outward of the TiO₂-comprising material at a temperature which does not transform the TiO₂-comprising material to be crystalline during said depositing of outer conductive metal capacitor electrode material; and

after the depositing of the outer conductive metal capacitor electrode material, annealing the substrate having the amorphous TiO₂-comprising material having thickness no greater than 50 Angstroms to form crystalline TiO₂-comprising material.

21. A method of forming a capacitor, comprising:

depositing inner conductive metal capacitor electrode material over a substrate;

forming a capacitor dielectric region outward of the inner conductive metal capacitor electrode material to a thickness no greater than 150 Angstroms, a dielectric constant k of at least 35, and leakage current no greater than 1×

10<sup>−

7</sup> amps/cm² at from −

1.1V to +1.1V;

the forming of the capacitor dielectric region comprising;

depositing a first Al₂O₃-comprising material outward of the inner conductive metal capacitor electrode material, the first Al₂O₃-comprising material having a thickness of from 2 Angstroms to 10 Angstroms;

depositing a TiO₂-comprising material outward of the first Al₂O₃-comprising material, the TiO₂-comprising material having a thickness of from 40 Angstroms to 80 Angstroms;

depositing a second Al₂O₃-comprising material outward of the TiO₂-comprising material, the second Al₂O₃-comprising material having a thickness of from 2 Angstroms to 10 Angstroms;

depositing an amorphous ZrO₂-comprising material to a thickness of from 30 Angstroms to 70 Angstroms outward of the second Al₂O₃-comprising material; and

annealing the amorphous ZrO₂-comprising material having thickness of from 30 Angstroms to 70 Angstroms after its deposition to form crystalline ZrO₂-comprising material; and

after the annealing of the amorphous ZrO₂-comprising material, depositing outer conductive metal capacitor electrode material outward of the crystalline ZrO₂-comprising material.

22. The method of claim 21 comprising depositing another Al₂O₃-comprising material outward of the crystalline ZrO₂-comprising material prior to the depositing of the outer conductive metal capacitor electrode material, the another Al₂O₃-comprising material being deposited to a thickness of from 2 Angstroms to 10 Angstroms.

23. A method of forming a capacitor, comprising:

depositing inner conductive metal capacitor electrode material over a substrate;

forming a capacitor dielectric region outward of the inner conductive metal capacitor electrode material to a thickness no greater than 150 Angstroms, a dielectric constant k of at least 40, and leakage current no greater than 5×

10^˜

8 amps/cm² at from −

1.1V to +1.1V;

the forming of the capacitor dielectric region comprising;

depositing a first Al₂O₃-comprising material outward of the inner conductive metal capacitor electrode material, the first Al₂O₃-comprising material having a thickness of from 2 Angstroms to 10 Angstroms;

depositing a TiO₂-comprising material outward of the first Al₂O₃-comprising material, the TiO₂-comprising material having a thickness of from 40 Angstroms to 80 Angstroms;

depositing a second Al₂O₃-comprising material outward of the TiO₂-comprising material, the second Al₂O₃-comprising material having a thickness of from 2 Angstroms to 10 Angstroms; and

depositing an amorphous ZrO₂-comprising material to a thickness greater than 35 Angstroms outward of the second Al₂O₃-comprising material; and

depositing outer conductive metal capacitor electrode material outward of the amorphous ZrO₂-comprising material at a temperature which transforms the amorphous ZrO₂-comprising material to be crystalline during said depositing of outer conductive metal capacitor electrode material.

24. The method of claim 23 comprising depositing another Al₂O₃-comprising material outward of the amorphous ZrO₂-comprising material prior to the depositing of the outer conductive metal capacitor electrode material, the another Al₂O₃-comprising material being deposited to a thickness of from 2 Angstroms to 10 Angstroms.

25. A method of forming a capacitor, comprising:

depositing inner conductive metal capacitor electrode material over a substrate;

forming a capacitor dielectric region outward of the inner conductive metal capacitor electrode material to a thickness no greater than 150 Angstroms, a dielectric constant k of at least 40, and leakage current no greater than 5×

10^˜

8 amps/cm² at from −

1.1V to +1.1V;

the forming of the capacitor dielectric region comprising;

depositing a first Al₂O₃-comprising material outward of the inner conductive metal capacitor electrode material, the first Al₂O₃-comprising material having a thickness of from 2 Angstroms to 10 Angstroms;

depositing a TiO₂-comprising material outward of the first Al₂O₃-comprising material, the TiO₂-comprising material having a thickness of from 40 Angstroms to 80 Angstroms;

depositing a second Al₂O₃-comprising material outward of the TiO₂-comprising material, the second Al₂O₃-comprising material having a thickness of from 2 Angstroms to 10 Angstroms; and

depositing an amorphous ZrO₂-comprising material to a thickness greater than 35 Angstroms outward of the second Al₂O₃-comprising material; and

depositing outer conductive metal capacitor electrode material outward of the amorphous ZrO₂-comprising material at a temperature which does not transform the amorphous ZrO₂-comprising material to be crystalline during said depositing of outer conductive metal capacitor electrode material; and

after the depositing of the outer conductive metal capacitor electrode material, annealing the substrate having the amorphous ZrO₂-comprising material having thickness greater than 35 Angstroms to form crystalline ZrO₂-comprising material.

26. A method of forming a capacitor, comprising:

depositing inner conductive metal capacitor electrode material over a substrate;

forming a capacitor dielectric region outward of the inner conductive metal capacitor electrode material to a thickness no greater than 150 Angstroms, a dielectric constant k of at least 40, and leakage current no greater than 5×

10^˜

8 amps/cm² at from −

1.1V to +1.1V;

the forming of the capacitor dielectric region comprising;

depositing an amorphous ZrO₂-comprising material to a thickness no greater than 35 Angstroms outward of the inner conductive metal capacitor electrode material;

annealing the amorphous ZrO₂-comprising material having thickness no greater than 35 Angstroms after its deposition to form crystalline ZrO₂-comprising material having a thickness no greater than 35 Angstroms;

after the annealing of the amorphous ZrO₂-comprising material, depositing an Al₂O₃-comprising material outward of the crystalline ZrO₂-comprising material, the Al₂O₃-comprising material having a thickness of from 2 Angstroms to 16 Angstroms;

depositing an amorphous TiO₂-comprising material to a thickness no greater than 50 Angstroms outward of the Al₂O₃-comprising material; and

annealing the amorphous TiO₂-comprising material having thickness no greater than 50 Angstroms in the presence of oxygen after its deposition to form crystalline TiO₂-comprising material; and

after the annealing of the amorphous TiO₂-comprising material, depositing outer conductive metal capacitor electrode material outward of the crystalline TiO₂-comprising material.

27. A method of forming a capacitor, comprising:

depositing inner conductive metal capacitor electrode material over a substrate;

forming a capacitor dielectric region outward of the inner conductive metal capacitor electrode material to a thickness no greater than 150 Angstroms, a dielectric constant k of at least 40, and leakage current no greater than 5×

10^˜

8 amps/cm² at from −

1.1V to +1.1V;

the forming of the capacitor dielectric region comprising;

depositing an amorphous ZrO₂-comprising material to a thickness no greater than 35 Angstroms outward of the inner conductive metal capacitor electrode material;

annealing the amorphous ZrO₂-comprising having thickness no greater than 35 Angstroms after its deposition to form crystalline ZrO₂-comprising material having a thickness no greater than 35 Angstroms;

after the annealing of the amorphous ZrO₂-comprising material, depositing an Al₂O₃-comprising material outward of the crystalline ZrO₂-comprising material, the Al₂O₃-comprising material having a thickness of from 2 Angstroms to 16 Angstroms; and

depositing an amorphous TiO₂-comprising material to a thickness greater than 50 Angstroms outward of the Al₂O₃-comprising material; and

depositing outer conductive metal capacitor electrode material outward of the TiO₂-comprising material at a temperature which transforms the amorphous TiO₂-comprising material to be crystalline during said depositing of outer conductive metal capacitor electrode material.

28. A method of forming a capacitor, comprising:

depositing inner conductive metal capacitor electrode material over a substrate;

forming a capacitor dielectric region outward of the inner conductive metal capacitor electrode material to a thickness no greater than 150 Angstroms, a dielectric constant k of at least 40, and leakage current no greater than 5×

10^˜

8 amps/cm² at from −

1.1V to +1.1V;

the forming of the capacitor dielectric region comprising;

depositing an amorphous ZrO₂-comprising material to a thickness no greater than 35 Angstroms outward of the inner conductive metal capacitor electrode material;

annealing the amorphous ZrO₂-comprising having thickness no greater than 35 Angstroms after its deposition to form crystalline ZrO₂-comprising material having a thickness no greater than 35 Angstroms;

after the annealing of the amorphous ZrO₂-comprising material, depositing an Al₂O₃-comprising material outward of the crystalline ZrO₂-comprising material, the Al₂O₃-comprising material having a thickness of from 2 Angstroms to 16 Angstroms; and

depositing an amorphous TiO₂-comprising material to a thickness greater than 50 Angstroms outward of the Al₂O₃-comprising material; and

depositing outer conductive metal capacitor electrode material outward of the TiO₂-comprising material at a temperature which does not transform the TiO₂-comprising material to be crystalline during said depositing of outer conductive metal capacitor electrode material; and

after the depositing of the outer conductive metal capacitor electrode material, annealing the substrate having the amorphous TiO₂-comprising material having thickness no greater than 50 Angstroms to form crystalline TiO₂-comprising material.

29. A method of forming a capacitor, comprising:

depositing inner conductive metal capacitor electrode material over a substrate;

forming a capacitor dielectric region outward of the inner conductive metal capacitor electrode material to a thickness no greater than 150 Angstroms, a dielectric constant k of least 40, and leakage current no greater than 5×

10<sup>−

8</sup> amps/cm² at from −

1.1V to +1.1V;

the forming of the capacitor dielectric region comprising;

depositing a first Al₂O₃-comprising material outward of the inner conductive metal capacitor electrode material, the first Al₂O₃-comprising material having a thickness of from 2 Angstroms to 10 Angstroms;

depositing a TiO₂-comprising material outward of the first Al₂O₃-comprising material, the TiO₂-comprising material having a thickness of from 40 Angstroms to 80 Angstroms;

depositing a second Al₂O₃-comprising material outward of the TiO₂-comprising material, the second Al₂O₃-comprising material having a thickness of from 2 Angstroms to 10 Angstroms;

depositing an amorphous ZrO₂-comprising material to a thickness of from 30 Angstroms to 70 Angstroms outward of the second Al₂O₃-comprising material; and

annealing the amorphous ZrO₂-comprising material having thickness of from 30 Angstroms to 70 Angstroms after its deposition to form crystalline ZrO₂-comprising material of from 30 Angstroms to 70 Angstroms; and

after the annealing of the amorphous ZrO₂-comprising material, depositing outer conductive metal capacitor electrode material outward of the crystalline ZrO₂-comprising material.