Selective metal deposition over dielectric layers
Selective deposition of metal over dielectric layers in a manner that minimizes or eliminates keyhole formation is provided. According to one embodiment, a dielectric target layer is formed over a substrate layer, wherein the target layer may be configured to allow conformal metal deposition, and a dielectric second layer is formed over the target layer, wherein the second layer may be configured to allow bottom-up metal deposition. An opening may then be formed in the second layer and metal may be selectively deposited over substrate layer.
1. A method of performing selective electroless plating comprising:
providing a substrate having a first dielectric layer thereover;
forming an opening extending only partially through the first dielectric layer;
forming a single conductive material directly on and in physical contact with the first dielectric layer, the single conductive material entirely filling the opening;
forming a hydrogen rich target layer over the conductive material, the hydrogen rich target layer comprising a hydrogen rich nitride material containing greater than 3 atomic percent hydrogen:
forming an opening to form a contact on the conductive material; and
performing selective electroless plating of a thin film over the contact.
2. The method of claim 1 wherein the target layer is hydrogen rich dielectric.
3. The method of claim 1 wherein the target layer further comprises chlorine.
4. The method of claim 1 further comprising forming a second dielectric layer over the target layer, wherein the second dielectric layer is oxide based.
5. The method of claim 4 wherein the second dielectric layer is formed at a temperature less than 600° C.
6. The method of claim 1 wherein the second dielectric layer is hydrogen poor relative to the target layer.
7. The method of claim 1 further comprising performing a preclean prior to performing selective electroless plating.
8. The method of claim 1 wherein the thin film comprises one or more members of the group consisting of nickel, thallium, phosphorous, gold, silver, copper, cobalt, palladium, platinum, boron, rhodium, iron, tungsten, binary alloys of these metals and ternary alloys of these metals.
9. The method of claim 1 wherein the thin film comprises a ternary alloy of nickel, thallium and boron.
10. The method of claim 1 wherein the thin film comprises a ternary ally of nickel, phosphorous and copper.
11. The method of claim 1 wherein the first dielectric layer comprises one or more members of the group consisting of SiO 2 , doped SiO 2 , phosphosilicate glass, tetraethyl orthosilicate, silicon oxynitride and any non-conductive metal nitride.
12. The method of claim 1 , wherein after formation of the first dielectric layer, a trench or via is formed in the first dielectric layer and wherein the conductive layer is formed within the via.
13. The method of claim 1 wherein the hydrogen rich target layer is formed over the conductive layer and over the first dielectric layer.
14. The method of claim 1 further comprising performing an activation pretreatment prior to the electroless plating, the pretreatment utilizing one or more of PdCl 2 and a tin-zinc combination.
15. A method of depositing metal over a dielectric material, comprising:
forming a dielectric material over a substrate;
forming a first opening partially through the dielectric material;
depositing a conductive material to entirely fill the opening;
forming a hydrogen rich dielectric material containing greater than 3 atomic percent hydrogen and chlorine over and in direct contact with the conductive material;
forming a non-hydrogen rich dielectric containing no more than 3 atomic percent hydrogen over the hydrogen rich dielectric material;
forming a second opening extending through the non-hydrogen rich dielectric material and the hydrogen rich dielectric material; and
depositing a metal material within the second opening and in direct contact with the conductive material.
16. The method of claim 15 wherein the hydrogen rich dielectric material contains approximately 6 atomic percent hydrogen.
17. The method of claim 15 wherein the hydrogen rich dielectric material comprises an oxide.
18. The method of claim 15 wherein the non-hydrogen rich dielectric material comprises an oxide.