Method of forming copper oxide film, method of etching copper film, method of fabricating semiconductor device, semiconductor manufacturing apparatus, and semiconductor device

• US 20030001271A1
• Filed: 09/04/2002
• Published: 01/02/2003
• Est. Priority Date: 01/25/2000
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Uozumi, Yoshihiro
• Granted Patent: US 6,818,556 B2
• Time in Patent Office: Days
• US Class Current: 257/758
• CPC Class Codes: C23C 22/63 Treatment of copper or alloys based thereon
• CPC Class Codes: H01L 21/02074 the processing being a planarization of conductive layers
• CPC Class Codes: H01L 21/02087 Cleaning of wafer edges
• CPC Class Codes: H01L 21/0209 Cleaning of wafer backside
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]
• CPC Class Codes: H01L 21/32134 by liquid etching only
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 21/76865 Selective removal of parts of the layer H01L21/76844 takes precedence
• CPC Class Codes: H01L 21/76883 Post-treatment or after-treatment of the conductive material
• CPC Class Codes: H01L 21/76885 By forming conductive members before deposition of protective insulating material, e.g. pillars, studs
• CPC Class Codes: H01L 21/76888 By rendering at least a portion of the conductor non conductive, e.g. oxidation

Abstract

A method of forming a copper oxide film comprises the step of forming a copper oxide film including an ammonia complex by causing a mixed solution of aqueous ammonia and aqueous hydrogen peroxide, which has been adjusted to have pH of 8 to 10 or pH of 9 to 10, to contact a surface of a copper film. A method of etching a copper film comprises the steps of forming a copper oxide film including an ammonia complex on a surface of the copper film by using the copper oxide film forming method as recited in any one of claims 1 to 3, and removing the copper oxide film from the copper film using acid or alkali. A method of fabricating a semiconductor device comprises the steps of burying a copper film to be a wiring or a contact wiring in a wiring groove or a contact hole formed in a surface of an insulating film formed on a semiconductor substrate, or in both the wiring groove and the contact hole, forming a copper oxide film including an ammonia complex on a surface of the copper film by using the copper oxide film forming method, and removing the copper oxide film from the copper film using acid or alkali.

Claims

1. A method of forming a copper oxide film comprising the step of forming a copper oxide film including an ammonia complex by causing a mixed solution of aqueous ammonia and aqueous hydrogen peroxide, which has been adjusted to have pH of 8 to 10 or pH of 9 to 10, to contact a surface of a copper film.

2. The method according to claim 1, further comprising a step of exposing said copper film having said copper oxide film formed on said surface thereof to a mixed solution of aqueous ammonia and aqueous hydrogen peroxide, which has been adjusted to have pH of 10 to 11.

4. The method according to claim 2, further comprising the step of selectively removing said copper oxide film from said copper film.

5. The method according to claim 4, wherein said copper oxide film removing step is carried out using acid or alkali.

6. A method of fabricating a semiconductor device comprising the steps of:

burying a copper film to be a wiring or a contact wiring in a wiring groove or a contact hole formed in a surface of an insulating film formed on a semiconductor substrate, or in both said wiring groove and said contact hole;

forming a copper oxide film including an ammonia complex on a surface of said copper film by using the copper oxide film forming method as recited in claim 2; and

selectively removing said copper oxide film from said copper film.

7. The method according to claim 6, wherein said surface of said copper film from which said copper oxide film has been removed is, etched deeper at a region closer to said wiring groove or said contact hole.

8. The method according to claim 7, wherein a barrier metal layer is intervened between said wiring groove or said contact hole and said buried copper film or between said wiring groove and contact hole and said buried copper film.

9. The method according to claim 8, further comprising the step of forming a barrier metal layer, on said copper film after removing said copper oxide film from said copper film.

10. The method according to claim 9, wherein said barrier metal layer intervened between said wiring groove or said contact hole and said buried copper film or between said wiring groove and contact hole and said buried copper film and said barrier metal layer formed on said copper film are made of different materials.

11. The method according to claim 10, further comprising the step of placing said surface of said copper film from which said copper oxide film has been removed in aqueous ammonia.

12. The method according to claim 11, wherein with said semiconductor substrate being rotated at a speed of 1000 rpm to 1600 rpm, said surface of said copper film is placed in said aqueous ammonia.

15. The method according to claim 14, wherein a main oxidizing agent in said chemical solution is hydrogen peroxide or ozone.

16. The method according to claim 15, wherein a main acid component in said chemical solution is sulfuric acid or hydrocyanic acid.

17. The method according to claim 16, further comprising the step of removing oxidizing agent contained in said chemical solution after the step of etching-out an unnecessary portion, the step of making metal ion concentration in said chemical solution approximately equal to metal ion concentration in said plating solution, and the step of using the chemical solution where said oxidizing agent has been removed as plating solution.

20. The semiconductor device according to claim 19, wherein said metal film is buried in said wiring groove or said contact hole via barrier metal.

21. The semiconductor device according to claim 20, wherein said barrier metal layer formed so as to cover said surface of said metal film has a structure where said barrier metal has been buried in said wiring groove or said contact hole.

3. A method of forming a copper oxide film comprising the steps of:

forming an oxide film on a surface of a copper film using aqueous hydrogen peroxide; and

forming a copper oxide film including an ammonia complex by placing said copper film having said oxide film formed thereon in a mixed solution of aqueous ammonia and aqueous hydrogen peroxide, which has been adjusted to have pH of 10 to 11.

13. A method of fabricating a semiconductor device comprising the steps of:

filling a wiring groove or a contact hole formed in an insulating film formed on a semiconductor substrate with wiring metal by depositing said wiring metal in said wiring groove or said contact hole;

exposing said insulating film by polishing said wiring metal;

cleaning said semiconductor substrate; and

carrying out recessing etching on a surface of said wiring metal buried in said wiring groove or said contact hole,

wherein chemical solutions used in at least two steps of said polishing step, said cleaning step and said recess etching step have the same main component.

14. A method of fabricating a semiconductor device comprising the steps of:

depositing metal or metal compound on a semiconductor substrate; and

etching out an unnecessary portion of said metal or metal compound by etching;

wherein said step of depositing metal or metal compound includes a plating step, component in plating solution used in said plating step forming salt or complex with a component to be plated is the same as a main component of chemical solution used in said etching-out step.

18. An apparatus of fabricating a semiconductor device comprising:

a metal plating chamber;

a post-CMP cleaning chamber;

an etching chamber; and

a processing chamber;

wherein the processing chamber is capable of removing oxidizing agent contained in chemical solution used in said etching chamber adjusting metal ion concentration in said chemical solution approximately equal to metal ion concentration in plating solution usable in said metal plating chamber, and returning said adjusted chemical solution to said metal plating chamber as plating solution.

19. A semiconductor device, comprising a semiconductor substrate;

a metal film buried in a wiring groove or a contact hole formed on an insulating film formed on said semiconductor substrate; and

a barrier metal layer formed in said wiring groove or said contact hole so as to cover a surface of said metal film;

wherein said surface of said metal film is formed so as to have the maximum height at a central portion of said wiring groove or said contact hole and have a reduced height towards a periphery of said wiring groove or said contact hole.