Etch back and film profile shaping of selective dielectric deposition
Self-aligned semiconductor device structures and techniques for fabrication thereof are provided. In one aspect, a self-aligned semiconductor device structure includes: at least one first conductive element embedded in a first dielectric; a second dielectric disposed selectively on the first dielectric relative to the at least one first conductive element; and at least one second conductive element present in the second dielectric that is fully aligned with the at least one first conductive element. A liner can be disposed on the second dielectric and which separates the second dielectric from the at least one second conductive element. A method of forming a self-aligned semiconductor device structure is also provided.
1 . A structure, comprising:
at least one first conductive element embedded in a first dielectric;
a second dielectric disposed selectively on the first dielectric relative to the at least one first conductive element;
at least one second conductive element present in the second dielectric that is fully aligned with the at least one first conductive element; and
a liner disposed on the second dielectric, wherein the liner is present along a top surface of the second dielectric and along only an upper portion of sidewalls of the at least one second conductive element such that the liner separates the upper portion of the at least one second conductive element from the second dielectric.
2 . The structure of claim 1 , wherein, at a juncture of the at least one first conductive element and the at least one second conductive element, sidewalls of the at least one first conductive element are aligned with sidewalls of the at least one second conductive element.
3 . The structure of claim 1 , wherein the liner comprises a material selected from the group consisting of: aluminum oxide (Al 2 O 3 ), zinc oxide (ZnO), titanium oxide (TiO 2 ), and combinations thereof.
4 . The structure of claim 1 , wherein the sidewalls of the at least one second conductive element are tapered such that a top of the at least one second conductive element has a width W 1 and a bottom of the at least one second conductive element has a width W 2 , and wherein W 1 >W 2 .
5 . The structure of claim 1 , wherein the sidewalls of the at least one second conductive element are bowed such that a top of the at least one second conductive element has a width W 1 , a bottom of the at least one second conductive element has a width W 2 , and a middle of the at least one second conductive element has a width W 3 , wherein W 3 >W 1 , and wherein W 3 >W 2 .
6 . The structure of claim 1 , wherein the first dielectric and the second dielectric each comprises a material selected from the group consisting of: silicon oxide (SiOx), organosilicate glass (SiCOH), carbon-rich SiCN, SiCNO, porous organosilicate glass (pSiCOH), pSiCN, pSiCNO and combinations thereof.
7 . The structure of claim 1 , wherein the at least one first conductive element and the at least one second conductive element comprise a metal selected from the group consisting of: copper (Cu), tungsten (W), cobalt (Co), ruthenium (Ru), copper manganese (CuMn), copper aluminum (CuAl), and combinations thereof.
8 . The structure of claim 1 , wherein the at least one first conductive element directly contacts the at least one second conductive element.