High-K MOM capacitor

• US 6,261,917 B1
• Filed: 05/09/2000
• Issued: 07/17/2001
• Est. Priority Date: 05/09/2000
• Status: Expired due to Term

• Current Assignee: Chartered Semiconductor Manufacturing Incorporated (GlobalFoundries, Inc.)
• Original Assignee: Chartered Semiconductor Manufacturing Incorporated (GlobalFoundries, Inc.)
• Inventors: Ang, Ting Cheong, Loong, Sang Yee, Quek, Shyue Fong, Ong, Puay Ing
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): Anya, Igwe U.
• Application Number:
  US09/567,420
• Time in Patent Office: 434 Days
• Field of Search: 438/396, 438/314, 438/317, 438/624, 438/635, 438/386, 438/253, 438/788, 438/910
• US Class Current: 438/396
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02183 the material containing tantalum, e.g. Ta2O5
• CPC Class Codes: H01L 21/02186 the material containing titanium, e.g. TiO2
• CPC Class Codes: H01L 21/02244 of a metallic layer
• 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 21/31683 of metallic layers, e.g. Al deposited on the body, e.g. formation of multi-layer insulating structures
• CPC Class Codes: H01L 28/40 Capacitors
• CPC Class Codes: H01L 28/75 comprising two or more layers, e.g. comprising a barrier layer and a metal layer

Abstract

A method for fabricating a metal-oxide-metal capacitor is described. A first insulating layer is provided overlying a semiconductor substrate. A barrier metal layer and a first metal layer are deposited over the insulating layer. A titanium layer is deposited overlying the first metal layer. The titanium layer is exposed to an oxidizing plasma while simultaneously a portion of the titanium layer where the metal-oxide-metal capacitor is to be formed is exposed to light whereby the portion of the titanium layer exposed to light reacts with the oxidizing plasma to form titanium oxide. Thereafter, the titanium layer is removed, leaving the titanium oxide layer where the metal-oxide-metal capacitor is to be formed. A second metal layer is deposited overlying the first metal layer and the titanium oxide layer. The second metal layer, titanium oxide layer, and first metal layer are patterned to form a metal-oxide-metal capacitor wherein the second metal layer forms an upper plate electrode, the titanium oxide layer forms a capacitor dielectric, and the first metal layer forms a bottom plate electrode of the MOM capacitor.

Claims

1. A method for fabricating a metal-oxide-metal capacitor comprising:

providing a first insulating layer overlying a semiconductor substrate;

depositing a first metal layer over said insulating layer;

depositing a second metal layer overlying said first metal layer;

exposing said second metal layer to an oxidizing plasma while simultaneously exposing a portion of said second metal layer where said metal-oxide-metal capacitor is to be formed to light whereby said portion of said second metal layer exposed to said light reacts with said oxidizing plasma to form a metal oxide;

thereafter removing said second metal layer leaving said metal oxide layer where said metal-oxide-metal capacitor is to be formed;

depositing a third metal layer overlying said first metal layer and said metal oxide layer; and

patterning said third metal layer, said metal oxide layer, and said first metal layer to form said metal-oxide-metal capacitor wherein said third metal layer forms an upper plate electrode, said metal oxide layer forms a capacitor dielectric, and said first metal layer forms a bottom plate electrode of said capacitor completing said fabrication of said metal-oxide-metal capacitor.

2. The method according to claim 1 wherein said semiconductor substrate includes semiconductor device structures such as gate electrodes and source and drain regions.

3. The method according to claim 2 further comprising forming contacts between some of said semiconductor device structures and said first metal layer to form a node contact of said metal-oxide-metal capacitor.

4. The method according to claim 1 wherein said semiconductor substrate includes semiconductor device structures such as gate electrodes and source and drain regions and multiple levels of metal interconnections.

5. The method according to claim 1 wherein said first metal layer comprises one of the group containing aluminum, aluminum alloys, copper, and copper alloys.

6. The method according to claim 1 further comprising depositing a barrier metal layer underlying said first metal layer wherein said barrier metal layer has a thickness of between about 50 and 200 Angstroms.

7. The method according to claim 1 wherein said second metal layer comprises one of the group containing titanium, aluminum, and tantalum and wherein said second metal layer has a thickness of between about 50 and 200 Angstroms.

8. The method according to claim 1 wherein said oxidizing plasma comprises one of the group containing O₂ and O₃.

9. The method according to claim 1 wherein said light comprises one of the group containing i-line light and ultra-violet light.

10. The method according to claim 1 wherein said steps of depositing and exposing said second metal layer are performed at room temperature.

11. The method according to claim 1 wherein said third metal layer comprises one of the group containing aluminum, aluminum alloys, copper, and copper alloys.

12. A method for fabricating a metal-oxide-metal capacitor comprising:

providing a first insulating layer overlying semiconductor device structures in and on a semiconductor substrate;

forming a contact through said first insulating layer to at least one of said semiconductor device structures wherein said contact will form a node contact for planned said metal-oxide-metal capacitor;

depositing a barrier metal layer overlying said first insulating layer and said contact;

depositing a first metal layer over said barrier metal layer;

depositing a titanium layer overlying said first metal layer;

exposing said titanium layer to an oxidizing plasma while simultaneously exposing to light a portion of said titanium layer where said metal-oxide-metal capacitor is to be formed overlying said contact whereby said portion of said titanium layer exposed to said light reacts with said oxidizing plasma to form titanium oxide;

thereafter removing said titanium layer leaving said titanium oxide layer where said metal-oxide-metal capacitor is to be formed;

depositing a second metal layer overlying said first metal layer and said titanium oxide layer; and

patterning said second metal layer, said titanium oxide layer, and said first metal layer to form said metal-oxide-metal capacitor wherein said second metal layer forms an upper plate electrode, said titanium oxide layer forms a capacitor dielectric, and said first metal layer forms a bottom plate electrode of said capacitor completing said fabrication of said metal-oxide-metal capacitor.

13. The method according to claim 12 wherein said semiconductor device structures include gate electrodes and source and drain regions.

14. The method according to claim 12 wherein said semiconductor device structures include gate electrodes and source and drain regions and multiple levels of metal interconnections.

15. The method according to claim 12 wherein said first metal layer comprises one of the group containing aluminum, aluminum alloys, copper, and copper alloys.

16. The method according to claim 12 wherein said barrier metal layer has a thickness of between about 50 and 200 Angstroms.

17. The method according to claim 12 wherein said titanium layer has a thickness of between about 50 and 200 Angstroms.

18. The method according to claim 12 wherein said oxidizing plasma comprises one of the group containing O₂ and O₃.

19. The method according to claim 12 wherein said light comprises one of the group containing i-line light and ultra-violet light.

20. The method according to claim 12 wherein said steps of depositing and exposing said titanium layer are performed at room temperature.

21. The method according to claim 12 wherein said second metal layer comprises one of the group containing aluminum, aluminum alloys, copper, and copper alloys.

22. A method for fabricating a metal-oxide-metal capacitor comprising:

providing a first insulating layer overlying semiconductor device structures in and on a semiconductor substrate;

forming a contact through said first insulating layer to at least one of said semiconductor device structures wherein said contact will form a node contact for planned said metal-oxide-metal capacitor;

depositing a barrier metal layer overlying said first insulating layer and said contact;

depositing a first metal layer over said barrier metal layer;

depositing a second metal layer overlying said first metal layer;

exposing said second metal layer to an oxidizing plasma comprising one of the group containing O₂ and O₃ while simultaneously exposing to light a portion of said second metal layer where said metal-oxide-metal capacitor is to be formed overlying said contact whereby said portion of said second metal layer exposed to said light reacts with said oxidizing plasma to form a metal oxide;

thereafter removing said second metal layer leaving said metal oxide layer where said metal-oxide-metal capacitor is to be formed;

depositing a third metal layer overlying said first metal layer and said metal oxide layer; and

patterning said third metal layer, said metal oxide layer, and said first metal layer to form said metal-oxide-metal capacitor wherein said third metal layer forms an upper plate electrode, said metal oxide layer forms a capacitor dielectric, and s aid first metal Layer forms a bottom plate electrode of said capacitor completing said fabrication of said metal-oxide-metal capacitor.

23. The method according to claim 22 wherein said semiconductor device structures include gate electrodes and source and drain regions.

24. The method according to claim 22 wherein said semiconductor device structures include gate electrodes and source and drain regions and multiple levels of metal interconnections.

25. The method according to claim 22 wherein said first metal layer comprises one of the group containing aluminum, aluminum alloys, copper, and copper alloys.

26. The method according to claim 22 wherein said barrier metal layer has a thickness of between about 50 and 200 Angstroms.

27. The method according to claim 22 wherein said second metal layer comprises one of the group containing titanium, aluminum, and tantalum, and wherein said second metal layer has a thickness of between about 50 and 200 Angstroms.

28. The method according to claim 22 wherein said light comprises one of the group containing i-line light and ultra-violet light.

29. The method according to claim 22 wherein said steps of depositing and exposing said second metal layer are performed at room temperature.

30. The method according to claim 22 wherein said third metal layer comprises one of the group containing aluminum, aluminum alloys, copper, and copper alloys.