Optimized wires for resistance or electromigration
View Patent ↗Optimized metal wires for resistance or electromigration, methods of manufacturing thereof and design methodologies are disclosed. The method includes depositing metal material within openings and on a surface of dielectric material resulting in metal filled openings and a topography of recessed areas aligned with the metal filled openings. The method further includes depositing an alloying material over the metal material, including within the recessed areas. The method further includes planarizing the metal material, leaving the alloying material within the recessed areas. The method further includes diffusing the alloying material into the metal material forming alloyed regions self-aligned with the metal filled openings.
1. A structure comprising a plurality of via interconnects and wiring structures formed in a dielectric material, the plurality of via interconnects and wiring structures are copper lined structures having a planar surface covered by a capping layer and self-aligned alloying regions with the via interconnects and wiring structures under the capping layer which inhibit electromigration, wherein the via interconnects and the wiring structures comprise a first copper lined metal material within openings of the dielectric material and a copper lined doped metal material on top of the first copper lined metal material, the copper lined doped metal material forms the self-aligned alloying regions.
2. The structure of claim 1 , wherein the self-aligned alloying regions comprise copper material diffused with one of Mn, Al, Co, Sn, Pd, C, Ca, Mg, and Hf.
3. The structure of claim 1 , wherein the wiring structures include the alloying regions aligned with underlying copper interconnect structures.
4. The structure of claim 1 , wherein the capping layer is silicon nitride.
5. The structure of claim 4 , wherein the capping layer has a planarized surface of metal material.
6. The structure of claim 5 , wherein the self-aligned alloying regions includes alloying material within recessed areas.
7. The structure of claim 6 , wherein the self-aligned alloying regions comprise a thin film formed on copper with a thickness of between about 0.1 to 200 nm.
8. The structure of claim 7 , wherein the thin film is Mn which diffuses into the copper.
9. The structure of claim 5 , further comprising a barrier layer on sidewalls and a bottom of trenches which confines the aligned alloying regions.
10. The structure of claim 9 , wherein the barrier layer is at least one of tantalum and tantalum nitride.
11. The structure of claim 1 , wherein the copper lined doped metal material completely fill an opening of the dielectric material.
12. The structure of claim 1 , wherein the self-aligned alloying regions are self aligned in a topography of recessed areas.
13. The structure of claim 12 , wherein the planar surface is above the topography of recessed areas.