Semiconductor device and method for manufacturing same

1. A semiconductor device comprising:

a semiconductor substrate;

an insulating film formed on said semiconductor substrate; and

a metal interconnect embedded in said insulating film,

wherein said metal interconnect comprises:

a base layer; and

an upper layer including atoms of a solid solution element disposed above said base layer,

wherein said upper layer is disposed at a first side of said metal interconnect that is opposite to a second side of said interconnect which is proximate to the semiconductor substrate,

wherein said metal interconnect comprises a first region where a via is provided and a second region where said via is not provided, and said solid solution element exists at said first regions and said second region,

wherein said semiconductor device further comprises a barrier metal film formed on said first side of said metal interconnect and said second side of said metal interconnect,

wherein said base layer includes atoms of said solid solution element, and

wherein a concentration of said atoms of said solid solution element in said base layer is lower than a concentration of said atoms of said solid solution element in said upper layer.

2. The semiconductor device according to claim 1 ,

wherein a metal constituting said metal interconnect comprises at least one of copper and an alloy containing copper.

3. The semiconductor device according to claim 1 ,

wherein an atomic radius of said atom of solid solution element is equal to or less than approximately 1.4 angstroms.

4. The semiconductor device according to claim 1 , wherein said solid solution element comprises silicon.

5. The semiconductor device according to claim 1 ,

wherein a region where said atoms of solid solution element are introduced forms a solid solution layer in a vicinity of said first side surface of said metal interconnect.

6. The semiconductor device according to claim 5 ,

wherein a concentration of said solid solution element in said solid solution layer is within a range from approximately 0.1 atomic % to approximately 9 atomic %.

7. The semiconductor device according to claim 5 ,

wherein a concentration of said solid solution element in a region of said metal interconnect other than said solid solution layer is less than approximately 0.1 atomic %.

8. The semiconductor device according to claim 5 ,

wherein a thickness of said solid solution layer is equal to or less than approximately 40% of a thickness of said metal interconnect.

9. The semiconductor device according to claim 1 , further comprising a film containing SiC, SiN, SiON or SiOC on the said first side of said metal interconnect.

10. The semiconductor device according to claim 1 , wherein said metal interconnect comprises a silicon solid solution layer comprising said atoms of solid solution silicon.

11. The semiconductor device according to claim 10 , wherein said silicon solid solution layer comprises a crystal lattice structure of copper having inter-lattice point silicon atoms.

12. The semiconductor device according to claim 10 , wherein said silicon solid solution layer is disposed between a lower silicon concentration region and a diffusion barrier film.

13. The semiconductor device according to claim 1 , wherein said metal interconnect comprises:

a lower silicon concentration region; and

a silicon solid solution layer comprising said atoms of solid solution silicon.

14. The semiconductor according to claim 1 , wherein said upper layer comprises a structure in which silicon atoms are introduced with a crystal lattice structure of copper that constitutes die metal interconnect to be disposed within the lattice as inter-lattice point atoms.

15. The semiconductor according to claim 1 , wherein said base layer comprises copper, and

wherein said solid solution element comprises silicon.