Methods of forming metal-insulator-metal (MIM) capacitors with separate seed
A metal-oxy-nitride seed dielectric layer can be formed on a metal-nitride lower electrode of a metal-insulator-metal (MIM) type capacitor. The metal-oxy-nitride seed dielectric layer can act as a barrier layer to reduce a reaction with the metal-nitride lower electrode during, for example, backend processing used to form upper levels of metallization/structures in an integrated circuit including the MIM type capacitor. Nitrogen included in the metal-oxy-nitride seed dielectric layer can reduce the type of reaction, which may occur in conventional type MIM capacitors. A metal-oxide main dielectric layer can be formed on the metal-oxy-nitride seed dielectric layer and can remain separate from the metal-oxy-nitride seed dielectric layer in the MIM type capacitor. The metal-oxide main dielectric layer can be stabilized (using, for example, a thermal or plasma treatment) to remove defects (such as carbon) therefrom and to adjust the stoichiometry of the metal-oxide main dielectric layer.
1. A method of forming a dielectric layer in a capacitor comprising:
forming a metal-oxy-nitride seed dielectric layer on a metal-nitride lower electrode using Atomic Layer Deposition (ALD) with a precursor gas including a metal and oxygen;
growing a metal-oxide main dielectric layer from the metal-oxy-nitride seed dielectric layer directly on the metal-oxy-nitride seed dielectric layer; and
treating the metal-oxy-nitride seed dielectric layer and the metal-oxide main dielectric layer using a thermal treatment or a plasma treatment to lower a crystallization temperature of the metal-oxide main dielectric layer.
2. A method according to claim 1 wherein a first metal constituent in the metal-nitride lower electrode and a second metal constituent in the metal-oxy-nitride seed dielectric layer comprise different metal constituents.
3. A method according to claim 2 wherein the different metal constituents comprise Ti, W, Ta, Hf, Zr, or La.
4. A method according to claim 1 wherein a first metal constituent in the metal-oxy-nitride seed dielectric layer and a second metal constituent in the metal-oxide main dielectric layer comprise the same metal constituent.
5. A method according to claim 4 wherein the same metal constituent comprises Ti, W, Ta, Hf, Zr, or La.
6. A method according to claim 1 wherein a metal constituent in the metal-oxide main dielectric layer and a metal constituent in the metal-oxy-nitride seed dielectric layer comprise the same metal constituents.
7. A method according to claim 1 wherein a second metal constituent in the metal-oxide main dielectric layer and a first metal constituent in the metal-oxy-nitride seed dielectric layer comprise different metal constituents.
8. A method according to claim 7 wherein the different metal constituents comprise Ti, W, Ta, Hf, Zr, or La.
9. A method according to claim 1 further comprising:
forming the metal-oxy-nitride seed dielectric layer to a thickness of about 20 to about 60 Angstroms; and
forming the metal-oxide main dielectric layer to a thickness of about 40 to about 100 Angstroms.
10. A method according to claim 1 wherein treating comprises treating the metal-oxide main dielectric layer using the thermal treatment or the plasma treatment in a non-oxygen atmosphere.
11. A method according to claim 10 wherein the non-oxygen atmosphere comprises H 2 , NH 3 and/or N 2 .
12. A method according to claim 1 wherein treating the metal-oxide main dielectric layer using thermal treatment comprises treating the metal-oxide main dielectric layer in an oxygen atmosphere at a temperature less than about 550 Centigrade.
13. A method according to claim 12 wherein the oxygen atmosphere comprises O 2 , NO 2 and/or N 2 O.
14. A method according to claim 1 wherein treating the metal-oxide main dielectric layer using plasma treatment comprises treating metal-oxide main dielectric layer using plasma treatment in an oxygen atmosphere at a temperature less than about 550 Centigrade.
15. A method according to claim 1 wherein forming a metal-oxy-nitride seed dielectric layer comprises:
forming a thin metal-oxy seed dielectric layer on the metal-nitride lower electrode; and
nitriding the thin metal-oxy seed dielectric layer.
16. A method according to claim 15 wherein nitriding comprises using a plasma treatment in a nitrogen atmosphere at a temperature of about 200 degrees Centigrade and about 550 degrees Centigrade.
17. A method according to claim 15 wherein nitriding comprises a thermal treatment in a nitrogen atmosphere at a temperature greater than or equal to about 550 degrees Centigrade.
18. A method according to claim 1 further comprising:
forming an upper electrode on the metal-oxide main dielectric layer, wherein a metal constituent included in the upper electrode is different than a metal constituent included in metal-oxide main dielectric layer.