Ruthenium oxide film and ruthenium liner for low-resistance copper interconnects in a device
View Patent ↗Selective ruthenium and selective ruthenium oxide may be used in single damascene processes and/or dual damascene processes to form BEOL metallization layers and vias of an electronic device. A selective ruthenium liner may be formed to achieve a low contact resistance and a low sheet resistance for the BEOL metallization layers and vias, to promote adhesion between the various layers and materials in the BEOL metallization layers and vias, and/or to reduce or eliminate defects (such as voids and discontinuities) in the BEOL metallization layers and vias.
1 . A device, comprising:
a dual damascene structure, included in one or more dielectric layers, comprising a via and a trench;
a ruthenium oxide film directly on sidewalls of the via and directly on sidewalls of the trench;
a ruthenium liner on the ruthenium oxide film; and
a copper layer on the ruthenium liner, wherein the ruthenium liner or the copper layer extends to a bottom surface of the via, and wherein the ruthenium liner is included on a bottom surface of the via between the bottom surface and the copper layer, wherein a thickness of the ruthenium liner on the bottom surface of the via is less than approximately 50% of a thickness of the ruthenium liner on the sidewalls of the via.
2 . The device of claim 1 , wherein a thickness of the ruthenium liner on the bottom surface of the via is greater than approximately 0 angstroms and less than approximately 10 angstroms.
3 . The device of claim 1 , wherein a thickness of the ruthenium liner on the bottom surface of the via is in a range between approximately 16 angstroms and approximately 48 angstroms.
4 . The device of claim 1 , wherein a thickness of the ruthenium liner on the bottom surface of the via is approximately equal to or greater than a thickness of the ruthenium liner on the sidewalls of the via.
5 . The device of claim 1 , wherein the ruthenium oxide film is directly on a bottom surface of the trench;
wherein the ruthenium liner is over the ruthenium oxide film on the bottom surface of the trench;
wherein a thickness of the ruthenium oxide film is in a range of approximately 2 angstroms to approximately 5 angstroms; and
wherein a thickness of the ruthenium liner is in a range of approximately 10 angstroms to approximately 35 angstroms.
6 . A device, comprising:
a metallization layer;
a dual damascene structure, in contact with the metallization layer, comprising a via;
a ruthenium oxide film on the dual damascene structure;
a ruthenium liner on the ruthenium oxide film; and
a copper layer on the ruthenium liner, wherein the ruthenium liner or the copper layer extends to a bottom surface of the via, and wherein the ruthenium liner is included on a bottom surface of the via between the bottom surface and the copper layer, wherein a thickness of the ruthenium liner on the bottom surface of the via is less than approximately 50% of a thickness of the ruthenium liner on the sidewalls of the via.
7 . The device of claim 6 , wherein the ruthenium oxide film is within the dual damascene structure.
8 . The device of claim 6 , wherein a bottom surface of the dual damascene structure is in contact with the metallization layer.
9 . The device of claim 6 , further comprising:
at least one of a dielectric layer or an etch stop layer,
wherein the dual damascene structure is within the at least one of the dielectric layer or the etch stop layer.
10 . The device of claim 9 , wherein the dual damascene structure is within the dielectric layer and the etch stop layer.
11 . The device of claim 9 , wherein the dielectric layer resides above the etch stop layer.
12 . The device of claim 9 , wherein the dual damascene structure is within the dielectric layer.
13 . The device of claim 9 , wherein the dual damascene structure is within the etch stop layer.
14 . A device, comprising:
a metallization layer;
a dual damascene structure comprising a via and a trench, wherein the via is in contact with the metallization layer;
a ruthenium oxide film on sidewalls of the via and on sidewalls of the trench; and
a ruthenium liner on the ruthenium oxide film, wherein the ruthenium liner extends to a bottom surface of the via, and wherein the ruthenium liner is included on a bottom surface of the via between the bottom surface and a copper layer, wherein a thickness of the ruthenium liner on the bottom surface of the via is less than approximately 50% of a thickness of the ruthenium liner on the sidewalls of the via.
15 . The device of claim 14 , further comprising:
an etch stop layer,
wherein the via is within the etch stop layer.
16 . The device of claim 15 , wherein the ruthenium liner is in contact with the metallization layer.
17 . The device of claim 15 , wherein the etch stop layer is over the metallization layer.
18 . The device of claim 15 , further comprising:
a dielectric layer,
wherein the via is within the etch stop layer and the dielectric layer.
19 . The device of claim 14 , further comprising:
a dielectric layer,
wherein the trench is within the dielectric layer.
20 . The device of claim 14 , wherein a thickness of the ruthenium oxide film over a bottom surface of the via is greater than 0 angstroms and less than approximately 5 angstroms.