INCREASING ELECTROMIGRATION RESISTANCE IN AN INTERCONNECT STRUCTURE OF A SEMICONDUCTOR DEVICE BY FORMING AN ALLOY
By introducing a metallic species into an exposed surface area of a copper region, the electromigration behavior of this surface area may be significantly enhanced. The incorporation of the metallic species may be accomplished in a highly selective manner so as to not unduly affect dielectric material positioned adjacent to the metal region, thereby essentially avoiding undue increase of leakage currents.
1 . A method, comprising:
forming a mask above a metal region formed in a dielectric material of a metallization layer of a semiconductor device, said mask exposing a surface of said metal region and covering said dielectric material;
applying a metallic species through said mask to said exposed surface of said metal region;
removing said mask; and
forming a dielectric cap material above said metallization layer, said dielectric cap material covering said surface containing said metallic species.
2 . The method of claim 1 , wherein applying said metallic species comprises performing an ion implantation process to introduce ions of said metallic species into said surface.
3 . The method of claim 1 , wherein applying said metallic species comprises performing plasma treatment in a plasma ambient containing ions of said metallic species.
4 . The method of claim 1 , wherein applying said metallic species comprises forming a metal layer comprised of said metallic species on said exposed surface.
5 . The method of claim 4 , wherein forming said metal layer comprises performing an electrochemical deposition process.
6 . The method of claim 4 , wherein forming said metal layer comprises depositing said metallic species by at least one of a chemical vapor deposition process and a physical vapor deposition process.
7 . The method of claim 1 , wherein said metallic species has an atomic radius that is greater than an atomic radius of copper.
8 . The method of claim 1 , further comprising forming a lower metallization layer prior to forming said metallization layer, wherein said lower metallization layer comprises a metal line, wherein said method further comprises forming said dielectric material above said lower metallization layer, forming a via opening in said dielectric material to expose a portion of said metal line and introducing said metallic species into a surface of said exposed portion.
9 . The method of claim 8 , wherein said metallic species is introduced by implanting said metallic species through said via opening.
10 . A method, comprising:
forming a metal layer above a dielectric layer of a metallization layer of a semiconductor device so as to fill an opening in said dielectric layer;
performing an implantation process to introduce a metallic species through an exposed surface of said metal layer; and
removing excess material of said metal layer from said dielectric layer to form a metal region in said dielectric layer, said metal region having a surface comprising said metallic species.
11 . The method of claim 10 , further comprising forming a conductive barrier material on said dielectric layer and an inner surface of said opening prior to forming said metal layer.
12 . The method of claim 11 , wherein forming said metal layer comprises depositing said metal layer by performing an electrochemical deposition process.
13 . The method of claim 10 , wherein said metal layer comprises copper and said metallic species is a non-copper containing species.
14 . The method of claim 13 , wherein said metallic species has an atomic radius that is greater than an atomic radius of copper.
15 . The method of claim 10 , wherein forming said metal layer comprises depositing a metal material with a first excess height and removing a portion of said metal material to obtain a second reduced excess height.
16 . The method of claim 10 , further comprising forming a lower metallization layer prior to forming said metallization layer, wherein said lower metallization layer comprises a metal line and wherein said method further comprises forming said dielectric layer above said lower metallization layer, forming a via opening in said dielectric layer to expose a portion of said metal line and introducing said metallic species into a surface of said exposed portion.
17 . The method of claim 16 , wherein said metallic species is introduced by implanting said metallic species through said via opening.
18 . A method, comprising:
forming a via opening in a dielectric layer, said via opening extending to and exposing a portion of a metal region formed in a first metallization layer of a semiconductor device;
performing an ion implantation process to introduce a metallic species into said exposed portion of said metal region; and
filling said via opening with a metal.
19 . The method of claim 18 , further comprising forming a trench in said dielectric layer, filling said trench with said metal to form a metal line and providing said metallic species at a surface of said metal line.
20 . The method of claim 19 , wherein providing said metallic species at the surface of said metal line comprises forming a mask above said dielectric layer to expose said surface and applying said metallic species on the basis of said mask.
21 . The method of claim 19 , wherein providing said metallic species at the surface of said metal line comprises forming a metal layer when filling said trench, introducing said metal species into said metal layer and removing excess material of said metal layer to expose said surface containing said metallic species.