Method for fabricating metal silicide

• US 6,884,473 B2
• Filed: 12/24/2002
• Issued: 04/26/2005
• 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
• Primary Examiner(s): CHEN, BRET P
• Application Number:
  US10/248,177
• Publication Number:
  US 20040121592A1
• Time in Patent Office: 854 Days
• Field of Search: 427/255.7, 427/530, 427/255.392, 427/255.393
• US Class Current: 427/530
• 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, wherein the substrate comprises a dielectric layer formed thereon;

forming a conductive layer on the dielectric layer, wherein the conductive layer comprises a nitrogen rich film formed within a top surface thereof, wherein the conductive layer is formed by performing a chemical vapor deposition process to form a doped polysilicon layer and then nitrogen ions are implanted on the doped polysilicon layer to form the nitrogen rich film within a top surface of the doped polysilicon layer; and

forming a metal silicide layer on the conductive layer.

2. The method of claim 1, further comprising a step of performing a deglaze on the conductive layer before the step of forming the metal silicide layer on the conductive layer.

3. The method of claim 1, wherein a thickness of the nitrogen rich film is about 20 angstroms.

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

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

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

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

forming a conductive layer on the dielectric layer;

performing an implantation process on the conductive layer to introduce nitrogen ions into a surface of the conductive layer to form a nitrogen rich film within a surface of the conductive layer; and

forming a metal silicide layer an the conductive layer.

7. The method of claim 6, further comprising a step of performing a deglaze process before the step of performing an implantation process.

8. The method of claim 7, wherein the deglaze process comprises performing an etching using a hydrofluoric acid gas.

9. The method of claim 6, wherein the implantation process comprises using a power of about 1000 electron volts to about 5000 electron volts and a concentration of the nitrogen ions of about 2×

10¹⁸ atoms/cm³ to 5×

10¹⁹ atoms/cm³.

10. The method of claim 6, wherein the nitrogen rich film is about 20 angstroms thick.

11. The method of claim 6, where the metal silicide layer is formed with a material selected from a group consisting of titanium silicide (TiSix), tungsten silicide (WSix), tantalum silicide (TaSix), molybdenum silicide (MoSix), cobalt silicide (CoSix) and nickel silicide (NiSix).

12. The method of claim 6, wherein the conductive layer includes polysilicon.

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

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

forming a conductive layer on the dielectric layer, wherein the conductive layer comprises a nitrogen rich film formed within a top surface thereof, wherein the conductive layer is formed via a chemical vapor deposition process, and nitrogen ions are introduced in-situ to form the nitrogen rich film within the top surface of the conductive layer; and

forming a metal silicide layer on the conductive layer.

14. The method of claim 13, further comprising a step of performing a deglaze on the conductive layer before the step of forming the metal silicide layer on the conductive layer.

15. The method of claim 13, wherein a thickness of the nitrogen rich film is about 20 angstroms.

16. The method of claim 13, wherein the metal silicide layer is formed with a material selected from a group consisting of titanium silicide (TiSix), tungsten silicide (WSix), tantalum silicide (TaSix), molybdenum silicide (MoSix), cobalt silicide (CoSix) and nickel silicide (NiSix).

17. The fabrication method of claim 13, wherein the conductive layer comprises a polysilicon layer.