METHOD FOR FABRICATING METAL SILICIDE

• US 20040121592A1
• Filed: 12/24/2002
• Published: 06/24/2004
• Est. Priority Date: 12/24/2002
• Status: Active Grant

• Current Assignee: Macronix International Co., Ltd.
• Original Assignee: Macronix International Co., Ltd.
• Inventors: CHANG, KENT KUOHUA
• Granted Patent: US 6,884,473 B2
• Time in Patent Office: Days
• US Class Current: 438/655
• CPC Class Codes: H01L 21/28044 the conductor comprising at least another non-silicon conductive layer
• CPC Class Codes: H01L 21/28061 the conductor comprising a metal or metal silicide formed by deposition, e.g. sputter deposition, i.e. without a silicidation reaction H01L21/28052 takes precedence
• CPC Class Codes: H01L 29/4941 with a barrier layer between the silicon and the metal or metal silicide upper layer, e.g. Silicide/TiN/Polysilicon

Abstract

A method for fabricating a metal silicide layer includes forming a dielectric layer on a substrate, followed by forming a polysilicon material conductive layer on the dielectric layer. An adhesion layer is then formed on the conductive layer, wherein the adhesion layer is a nitrogen rich layer or a nitrogen ion implanted layer. A metal silicide layer is then formed on the adhesion layer. The adhesion between the metal silicide layer and the conductive layer is more desirable due the adhesion layer.

Claims

1. A method for fabricating a metal silicide, comprising:

providing a substrate, where the substrate comprises a dielectric layer already formed thereon;

forming a conductive layer on the dielectric layer;

forming an adhesion layer on the conductive layer; and

forming a metal silicide layer on the adhesion layer.

2. The method of claim 1, wherein the adhesion layer includes a nitrogen rich film.

3. The method of claim 1, wherein the adhesion layer is formed by chemical vapor deposition to dope nitrogen ions in situ, wherein a concentration of the nitrogen ions is about 2×

10¹⁸ atoms/cm³ to 5×

10¹⁹ atoms/cm³.

4. The method of claim 2, wherein the adhesion layer is about 5 angstroms to 40 angstroms thick.

8. The method of claim 1, wherein the metal silicide layer is formed with a material selected from the group consisting of titanium silicide (TiSix), tungsten silicide (WSix), tantalum silicide (TaSix), molybdenum silicide (MoSix), cobalt silicide (CoSix) and nickel silicide (NiSix).

9. The fabrication method of claim 1, wherein the conductive layer comprises polysilicon.

5. The method of claim 5, wherein the adhesion layer includes a nitrogen ion implanted layer.

6. The method of claim 5, wherein the adhesion layer is formed by an ion implantation process using a power of about 1000 electron volts to about 5000 electron volts to implant nitrogen ions into the conductive layer, wherein a concentration of the nitrogen ions is about 2×

10¹⁸ atoms/cm³ to 5×

10¹⁹ atoms/cm³.

7. The method of claim 5, wherein the adhesion layer is about 20 angstroms thick.

10. A fabrication method of a metal silicide layer, comprising:

providing a substrate, wherein the substrate already comprises a dielectric layer formed thereon;

forming a conductive layer on the dielectric layer;

performing a deglaze process on the conductive layer;

forming an adhesion layer on the conductive layer and forming a metal silicide layer on the adhesion layer.

11. The method of claim 10, wherein the deplaze process comprises performing an etching using a hydrofluoric acid gas.

12. The method of claim 10, wherein the adhesion layer includes a nitrogen rich film.

13. The method of claim 12, wherein the adhesion layer is formed by a chemical vapor deposition method to dope nitrogen ions in-situ, wherein a concentration of the nitrogen ions is about 2×

10¹⁸ atoms/cm³ to 5×

10¹⁹ atoms/cm³.

14. The method of claim 12, wherein the adhesion layer is about 5 angstroms thick to 40 angstroms thick.

15. The method of claim 10, wherein the adhesion layer includes a nitrogen ion implanted layer.

16. The method of claim 15, wherein the adhesion layer is formed by an ion implantation process using a power of about 1000 electron volts to about 5000 electron volts to implant nitrogen ions to the conductive layer, wherein a concentration of the nitrogen ions is about 2×

10¹⁸ atoms/cm³ to 5×

10¹⁹ atoms/cm³.

17. The method of claim 15, wherein the adhesion layer is about 20 angstroms thick.

18. The method of claim 10, where the metal silicide layer is formed with a material selected from the group consisting of titanium silicide (TiSix), tungsten silicide (WSix), tantalum silicide (TaSix), molybdenum silicide (MoSix), cobalt silicide (CoSix) and nickel silicide (NiSix).

19. The method of claim 10, wherein the conductive layer includes polysilicon.