Semiconductor device and method for manufacturing same

Abstract

An improved SIV resistance and an improved EM resistance are achieved in the coupling structure containing copper films. A semiconductor device includes: a semiconductor substrate; a second insulating layer formed on or over the semiconductor substrate; a second barrier metal film, formed on the second insulating film, and being capable of preventing copper from diffusing into the second insulating film; and an electrically conducting film formed on the second barrier metal film so as to be in contact with the second barrier metal film, and containing copper and carbon, wherein a distribution of carbon concentration along a depositing direction in the second electrically conducting film includes a first peak and a second peak.

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, partially illustrating a configuration of a semiconductor device in an embodiment of the present invention;

FIGS. 2A and 2B are cross-sectional views of a semiconductor device, illustrating a procedure for manufacturing the semiconductor device in an embodiment of the present invention;

FIGS. 3A and 3B are cross-sectional views of the semiconductor device, illustrating the procedure for manufacturing the semiconductor device in the embodiment of the present invention;

FIGS. 4A and 4B are cross-sectional views of the semiconductor device, illustrating the procedure for manufacturing the semiconductor device in the embodiment of the present invention;

FIGS. 5A and 5B are charts, showing results of an example;

FIGS. 6A to 6C are charts, showing results of an example;

FIGS. 7A to 7C are charts, showing results of an example;

FIG. 8 is a graph, showing results of an example; and

FIG. 9 is a cross-sectional view, partially illustrating a configuration of a semiconductor device in an embodiment of the present invention.

Claims

1. A semiconductor device, comprising: a semiconductor substrate;an insulating film formed on or over said semiconductor substrate;a barrier metal film, formed on said insulating film; andan electrically conducting film formed on said barrier metal film so as to be in contact with said barrier metal film, and containing copper, a metal having a standard electrode potential that is lower than that of copper, and carbon,wherein a distribution of carbon concentration along a depositing direction in said electrically conducting film includes a first peak and a second peak, andwherein said metal having a standard electrode potential that is lower than that of copper is contained in an interface between said electrically conducting film and said barrier metal film at higher concentration than in other regions.

2. The semiconductor device according to claim 1, wherein said metal having a standard electrode potential that is lower than that of copper is selected from a group consisting of aluminum (Al), tin (Sn) and titanium (Ti).

3. The semiconductor device according to claim 1, wherein said barrier metal film is formed on a bottom surface and a side surface of a concave portion formed in said insulating film,wherein said electrically conducting film is formed to fill said concave portion,wherein said first peak and said second peak appears in this order from the interface between said barrier metal film and said electrically conducting film, andwherein said first peak exists at a position of a height equal to or more than 50 nm to equal to or less than 100 nm from said interface.

4. The semiconductor device according to claim 2, wherein said barrier metal film is formed on a bottom surface and a side surface of a concave portion formed in said insulating film,wherein said electrically conducting film is formed to fill said concave portion,wherein said first peak and said second peak appears in this order from the interface between said barrier metal film and said electrically conducting film, andwherein said first peak exists at a position of a height equal to or more than 50 nm to equal to or less than 100 nm from said interface.

5. The semiconductor device according to claim 1, wherein said barrier metal film is formed on a bottom surface and a side surface of a concave portion formed in said insulating film,wherein said electrically conducting film is formed to fill said concave portion,wherein said first peak and said second peak appears in this order from a bottom surface of said concave portion, andwherein said second peak appears at a position of a height equal to or more than 0.75 h to equal to or less than 0.9 h from said interface between said barrier metal film and said electrically conducting film, provided that h is a depth of said concave portion.

6. The semiconductor device according to claim 2, wherein said barrier metal film is formed on a bottom surface and a side surface of a concave portion formed in said insulating film,wherein said electrically conducting film is formed to fill said concave portion,wherein said first peak and said second peak appears in this order from a bottom surface of said concave portion, andwherein said second peak appears at a position of a height equal to or more than 0.75 h to equal to or less than 0.9 h from said interface between said barrier metal film and said electrically conducting film, provided that h is a depth of said concave portion.

7. A method for manufacturing a semiconductor device including a semiconductor substrate; an insulating film formed on or over said semiconductor substrate; a barrier metal film, formed on said insulating film; and an electrically conducting film formed on said barrier metal film so as to be in contact with said barrier metal film, and containing copper, a metal having a standard electrode potential that is lower than that of copper, and carbon, wherein a distribution of carbon concentration along a depositing direction in said electrically conducting film includes a first peak and a second peak, and wherein said metal having a standard electrode potential that is lower than that of copper is contained in an interface between said electrically conducting film and said barrier metal film at higher concentration than in other regions, said method comprising: forming a concave portion in an insulating film formed on or over a semiconductor substrate;forming a barrier metal film in said concave portion;forming a seed metallic film in said concave portion, said seed metallic film containing copper, a metal having a standard electrode potential that is lower than that of copper; andfilling said concave portion with a plated film containing copper by an electrolytic plating process utilizing said seed metallic film as an electrode and employing a copper plating solution that contains a polymer having molecular weight equal to or more than 500 to equal to or less than 2,000 as an inhibitor,wherein said filling the concave portion with said plated film includes: a first operation for performing said electrolytic plating process by utilizing a first current density; and a second operation for performing said electrolytic plating process by utilizing a current density that is higher than said first current density, after said first operation.

8. A method for manufacturing a semiconductor device, comprising: forming a concave portion in an insulating film formed on or over a semiconductor substrate;forming a barrier metal film in said concave portion;forming a seed metallic film in said concave portion, said seed metallic film containing copper, a metal having a standard electrode potential that is lower than that of copper; andfilling said concave portion with a plated film containing copper by an electrolytic plating process utilizing said seed metallic film as an electrode and employing a copper plating solution that contains a polymer having molecular weight equal to or more than 500 to equal to or less than 2,000 as an inhibitor,wherein said filling the concave portion with said plated film includes: a first operation for performing said electrolytic plating process by utilizing a first current density; and a second operation for performing said electrolytic plating process by utilizing a current density that is higher than said first current density, after said first operation, andwherein, in said first operation and said second operation, carbon is introduced in said seed metallic film and said plated film so that distributions of carbon concentration in depositing direction in said seed metallic film and in said plated film have a first peak and a second peak.