Semiconductor device and method for manufacturing same

Abstract

An improved migration resistance of the interconnect is provided and a diffusion of silicon into the inside of the interconnect is suppressed. A semiconductor device includes a silicon substrate, a first insulating film provided on the silicon substrate and composed of an SiCN film, an SiOC film and an SiO2 film, and a first copper interconnect provided in the first insulating film and essentially composed of a copper-containing metal. An Si—O unevenly distributed layer doped with injected silicon is included in the vicinity of the surface in the inside of the first copper interconnect, and injected atomic silicon at least partially creates Si—O bond.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, advantages and features of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a cross-sectional view of a semiconductor device, illustrating a configuration of a semiconductor device in the present embodiment;

FIGS. 2A to 2C are cross-sectional views of the semiconductor device, illustrating a process for manufacturing of the semiconductor device of FIG. 1;

FIGS. 3A to 3C are cross-sectional views of the semiconductor device, illustrating a process for manufacturing of the semiconductor device of FIG. 1;

FIGS. 4A and 4B are cross-sectional views of the semiconductor device, illustrating a process for manufacturing of the semiconductor device of FIG. 1;

FIG. 5 is a cross-sectional view of a semiconductor device, illustrating a configuration of a semiconductor device in the present embodiment;

FIGS. 6A to 6C are cross-sectional views of the semiconductor device, illustrating a process for manufacturing of the semiconductor device of FIG. 5;

FIGS. 7A and 7B are cross-sectional views of the semiconductor device, illustrating a process for manufacturing of the semiconductor device of FIG. 5;

FIG. 8 is a bar chart, showing results of evaluations on EM of the semiconductor devices in examples;

FIG. 9 is a graph, showing results of evaluations on EM of the semiconductor devices in examples;

FIG. 10 is a bar chart, showing results of evaluations on breakdown voltage of the semiconductor devices in examples;

FIGS. 11A and 11B are charts of XPS analysis results for the semiconductor devices in examples;

FIG. 12 is a cross-sectional view of a semiconductor device, illustrating a position for conducting an EELS analysis for the semiconductor devices in examples;

FIG. 13 is a bar chart, showing results of TEM-EELS analysis for the semiconductor devices in examples;

FIG. 14 is a graph, showing results of measured interconnect capacitances for the semiconductor devices in examples;

FIG. 15 is a cross-sectional view of a semiconductor device, illustrating a configuration of a semiconductor device in the present embodiment; and

FIG. 16 is a cross-sectional view of a semiconductor device, illustrating a configuration of a semiconductor device in the present embodiment;

Claims

1. A semiconductor device, comprising: a substrate;a first insulating film provided on said substrate; andan interconnect, provided in said first insulating film, and essentially composed of a copper-containing metal,wherein said semiconductor device includes a region doped with injected silicon in the vicinity of a surface of said interconnect in the inside of said interconnect, and injected atomic silicon at least partially forms silicon-oxygen (Si—O) bond.

2. The semiconductor device according to claim 1, wherein said region doped with silicon is provided in the vicinity of the surface of said interconnect in the inside of said interconnect to form a layered structure.

3. The semiconductor device according to claim 1, wherein atomic silicon injected into the region in the vicinity of the surface of said interconnect in the inside of said interconnect partially creates Si—O bond.

4. The semiconductor device according to claim 1, wherein injected atomic silicon at least partially creates Si—N bond.

5. The semiconductor device according to claim 4, wherein injected atomic silicon substantially totally creates Si—O bond or Si—N bond.

6. The semiconductor device according to claim 4, wherein Si—N bond is included in the vicinity of the surface in the inside of said first insulating film in a region having none of said interconnect formed therein.

7. The semiconductor device according to claim 1, wherein a copper silicide layer is not formed in the vicinity of the surface of said interconnect in the inside of said interconnect.

8. The semiconductor device according to claim 1, wherein ratio of silicon to the whole elements constituting said interconnect contained in the vicinity of the surface of said interconnect in the inside of said interconnect is not less than 5 atomic % and not more than 30 atomic %.

9. The semiconductor device according to claim 1, wherein said first insulating film includes a low dielectric constant film.

10. The semiconductor device according to claim 1, further comprising a second insulating film provided on said first insulating film so as to be in contact with said interconnect,

11. The semiconductor device according to claim 1, wherein substantially no Cu—O bond is included in the vicinity of the surface of said interconnect in the inside of said interconnect.

12. The semiconductor device according to claim 1, further comprising an electroconductive connecting plug provided on said interconnect, wherein a bottom of said connecting plug is located in said region doped with silicon.

13. The semiconductor device according to claim 1, further comprising an electroconductive connecting plug provided on said interconnect, wherein a bottom of said connecting plug is located in a position in the inside of said interconnect, which is closer to said substrate than said region doped with silicon.

14. A method for manufacturing a semiconductor device, comprising: forming a first insulating film on a substrate;forming an interconnect in said first insulating film, said interconnect being essentially composed of a copper-containing metal;inducing a reduction of copper in the vicinity of a surface of said interconnect;injecting silicon in the vicinity of a surface of said interconnect in the inside of said interconnect by exposing an upper portion of said interconnect to a gas containing silicon, after said inducing a reduction of copper; andat least partially inducing silicon injected in said injecting silicon to create Si—O bond.

15. The method for manufacturing a semiconductor device according to claim 14, wherein said at least partially inducing injected silicon to create Si—O bond includes partially inducing silicon injected in the vicinity of the surface in the inside of said interconnect to create Si—O bond.

16. The method for manufacturing a semiconductor device according to claim 14, further comprising at least partially inducing injected silicon to create Si—N bond, after said injecting silicon and before at least partially inducing injected silicon to create Si—O bond.

17. The method for manufacturing a semiconductor device according to claim 16, wherein said at least partially inducing injected silicon to create Si—N bond includes inducing injected silicon to create Si—N bond in the vicinity of the surface in the inside of said first insulating film.

18. The method for manufacturing a semiconductor device according to claim 14, wherein said at least partially inducing injected silicon to create Si—O bond includes oxidizing the upper portion of said interconnect,wherein said method further includes forming a second insulating film so as to be in contact with said first insulating film having said interconnect formed therein, after said at least partially inducing injected silicon to create Si—O bond, andwherein said forming the second insulating film includes forming a film selected from a group consisting of an SiC film, an SiCN film, an SiCO film, an SiCON film and an SiN film.

19. The method for manufacturing a semiconductor device according to claim 14, wherein said at least partially inducing injected silicon to create Si—O bond includes oxidizing the upper portion of said interconnect, andwherein said oxidizing the upper portion of the interconnect includes heat-treating said substrate having said interconnect formed thereon.

20. The method for manufacturing a semiconductor device according to claim 14, further comprising forming a second insulating film so as to be in contact with said first insulating film having said interconnect formed therein, after said injecting silicon and before said at least partially inducing injected silicon to create Si—O bond,wherein said forming the second insulating film includes forming a film selected from a group consisting of: SiC film, SiCN film, SiCO film, SiCON film and SiN film, andwherein said at least partially inducing injected silicon to create Si—O bond includes diffusing oxygen to a vicinity of the surface in the inside of said interconnect through said second insulating film.