Method of forming a capacitor

• US 6,919,257 B2
• Filed: 06/14/2002
• Issued: 07/19/2005
• Est. Priority Date: 04/06/1999
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Graettinger, Thomas M., Gealy, F. Daniel
• Primary Examiner(s): TRINH, MICHAEL MANH
• Application Number:
  US10/172,253
• Publication Number:
  US 20030057472A1
• Time in Patent Office: 1,131 Days
• Field of Search: 438/396, 438/255, 438/398, 438/397, 438/253, 438/254
• US Class Current: 438/398
• 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 23/5223 Capacitor integral with wiring layers
• CPC Class Codes: H01L 28/55 with a dielectric comprising a perovskite structure material
• CPC Class Codes: H01L 28/65 comprising a noble metal or a noble metal oxide, e.g. platinum (Pt), ruthenium (Ru), ruthenium dioxide (RuO2), iridium (Ir), iridium dioxide (IrO2)
• CPC Class Codes: H01L 28/84 being a rough surface, e.g. using hemispherical grains
• CPC Class Codes: H01L 28/90 having vertical extensions
• CPC Class Codes: H01L 28/91 made by depositing layers, e.g. by depositing alternating conductive and insulating layers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A method of forming a capacitor is disclosed. The method includes forming a first electrode having a non-smooth surface and selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof. The method further includes forming a second electrode, and forming a dielectric between the first and second electrodes.

Claims

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

forming an opening in a substrate assembly, wherein the opening extends to a first surface of an interconnect recessed within the substrate assembly;

forming a non-smooth mold in the opening and on the first surface of the interconnect;

removing a portion of the non-smooth mold from the first surface of the interconnect;

forming a first electrode having a non-smooth surface, wherein forming the first electrode includes forming the first electrode on the non-smooth mold and the first surface of the interconnect with a material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof;

forming a dielectric on the first electrode and an uppermost surface of the substrate assembly; and

forming a second electrode on the dielectric and the uppermost surface of the substrate assembly, wherein forming the second electrode includes forming at least one non-smooth surface.

2. The method of claim 1, wherein forming the opening in the substrate assembly includes etching the substrate assembly.

3. The method of claim 2, wherein etching the substrate assembly includes anisotropically etching the substrate assembly.

4. The method of claim 1, wherein forming the non-smooth mold in the opening includes forming a layer of hemispherical grain polysilicon.

5. The method of claim 4, wherein forming the layer of hemispherical grain polysilicon includes depositing a layer of hemispherical grain polysilicon in the opening.

6. The method of claim 5, wherein depositing the layer of hemispherical grain polysilicon includes depositing a layer of hemispherical grain polysilicon by chemical vapor deposition.

7. The method of claim 1, wherein removing the portion of the non-smooth mold includes etching the non-smooth mold.

8. The method of claim 1, wherein forming the first electrode on the non-smooth mold and the interconnect includes depositing a material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof on the non-smooth mold and the interconnect.

9. The method of claim 8, wherein depositing the material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof on the non-smooth mold and the interconnect includes depositing a material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof on the non-smooth mold and the interconnect by chemical vapor deposition.

10. The method of claim 8, wherein depositing the material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof on the non-smooth mold and the interconnect includes sputtering a material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof on the non-smooth mold and the interconnect.

11. The method of claim 8, wherein depositing the material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof on the non-smooth mold and the interconnect includes depositing a transition metal selected from the group consisting of Pt, Rh, Ir, Ru, and Pd.

12. The method of claim 8, wherein depositing the material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof on the non-smooth mold and the interconnect includes depositing a conductive oxide selected from the group consisting of IrO_x, RuO_x, and RhO_x, wherein X<

4.

13. The method of claim 1, wherein forming the dielectric includes:

removing a portion of the substrate assembly; and

removing the non-smooth mold.

14. The method of claim 13, wherein removing the portion of the substrate assembly includes etching the substrate assembly.

15. The method of claim 13, wherein removing the non-smooth mold includes removing a layer of hemispherical grain polysilicon.

16. The method of claim 15, wherein removing the layer of hemispherical grain polysilicon includes etching a layer of hemispherical grain polysilicon.

17. The method of claim 13, wherein forming the dielectric includes forming a non-smooth surface.

18. The method of claim 13, wherein forming the dielectric includes depositing an insulating metal oxide.

19. The method of claim 18, wherein depositing the insulating metal oxide includes depositing a material selected from the group consisting of barium strontium titanate, SrTiO₃, Sr_wBi_xTa_yO_z, BaxSr_1-xTiO₃, where 0<

x<

1, and Ta₂O₅ by chemical vapor deposition.

20. The method of claim 18, wherein depositing the insulating metal oxide includes sputtering a material selected from the group consisting of barium strontium titanate, SrTiO₃, Sr_wBi_xTa_yO_z, BaxSr_1-xTiO₃, where 0<

x<

1, and Ta₂O₅.

21. The method of claim 1, wherein forming the second electrode includes depositing a material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof on the dielectric and the uppermost surface of the substrate assembly.

22. The method of claim 21, wherein depositing the material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof includes depositing a material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof by chemical vapor deposition.

23. The method of claim 21, wherein depositing the material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof includes sputtering a material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof.

24. The method of claim 21, wherein depositing the material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof includes depositing a transition metal selected from the group consisting of Pt, Rh, Ir, Ru, and Pd.

25. The method of claim 21, wherein depositing the material selected from the group consisting of transition metals, conductive oxides, alloys thereof, and combinations thereof includes depositing a conductive oxide selected from the group consisting of IrO_x, RuO_x, and RhO_x, wherein x<

4.

26. The method of claim 1, wherein forming the second electrode includes depositing a material selected from the group consisting of conductive metal nitrides, aluminum, and polysilicon on the dielectric and the uppermost surface of the substrate assembly.

27. The method of claim 26, wherein depositing the material selected from the group consisting of conductive metal nitrides, aluminum, and polysilicon includes depositing a conductive metal nitride selected from the group comprising WN, TiN, and TaN.