Conformal capacitor structure formed by a single process
A capacitor structure is provided that includes conformal layers of a lower electrode, a high-k metal oxide dielectric, and an upper electrode. The capacitor structure is formed by a single process which enables the in-situ conformal deposition of the electrode and dielectric layers of the capacitor structure. The single process includes atomic layer deposition in which a metal-containing precursor is selected to provide each of the layers of the capacitor structure. The lower electrode layer is formed by utilizing the metal-containing precursor and a first reactive gas, the high-k metal oxide dielectric layer is provided by switching the first reactive gas to a second reactive gas, and the upper electrode layer is provided by switching the second reactive gas back to the first reactive gas.
1. A semiconductor structure comprising:
a capacitor structure located in a bottle-shaped opening present in a semiconductor substrate, wherein the bottle-shaped opening has sidewalls and a bottom wall and the capacitor structure comprises:
a lower electrode layer composed of a first metal nitride and lining an entirety of the sidewalls and the bottom wall of the bottle-shaped opening that is present in the semiconductor substrate;
a high-k metal oxide dielectric layer located entirely on, and in direct physical contact with an entirety of, the lower electrode layer; and
an upper electrode layer composed of a second metal nitride and located entirely on, and in direct physical with an entirely of, the high-k metal oxide dielectric layer, wherein each of the lower electrode, the high-k metal oxide dielectric layer and the upper electrode layer is a conformal layer, and wherein the first metal nitride and the second metal nitride are composed of a same metal nitride and wherein the metal of the first and second metal nitrides is the same as the metal of the high-k metal oxide dielectric layer.
2. The semiconductor structure of claim 1 , wherein the bottle-shaped opening has a lower portion of a first width, w 1 , and an upper portion of a second width, w 2 , wherein w 2 is less than w 1 .
3. The semiconductor structure of claim 2 , wherein w 1 is at least 1.5 times greater than the w 2 .
4. The semiconductor structure of claim 2 , wherein w 1 is from 15 nm to 1500 nm, and w 2 is from 10 nm to 1000 nm.
5. The semiconductor structure of claim 1 , wherein the first metal nitride and the second metal nitride are selected from a group consisting of niobium (Nb) nitride, titanium (Ti) nitride, zirconium (Zr) nitride, hafnium (Hf) nitride, and tantalum (Ta) nitride.
6. The semiconductor structure of claim 1 , wherein the first metal nitride and the second metal nitride are composed of Nb nitride and the high-k metal oxide dielectric layer is composed of niobium oxide.
7. The semiconductor structure of claim 1 , wherein the lower electrode layer has a thickness from 5 nm to 50 nm.
8. The semiconductor structure of claim 1 , wherein the high-k metal oxide dielectric layer has a thickness from 1 nm to 20 nm.
9. The semiconductor structure of claim 1 , wherein upper electrode layer has a thickness from 5 nm to 50 nm.
10. A semiconductor structure comprising:
a capacitor structure located in a bottle-shaped opening present in a semiconductor substrate, wherein the bottle-shaped opening has sidewalls and a bottom wall and the capacitor structure comprises:
a lower electrode layer composed of a first metal and lining an entirety of the sidewalls and the bottom wall of the bottle-shaped opening that is present in the semiconductor substrate;
a high-k metal oxide dielectric layer located entirely on, and in direct physical contact with an entirety of, the lower electrode layer; and
an upper electrode layer composed of a second metal and located entirely on, and in direct physical contact with an entirety of, the high-k metal oxide dielectric layer, wherein each of the lower electrode, the high-k metal oxide dielectric layer and the upper electrode layer is a conformal layer, and wherein the first metal and the second metal are composed of a same metal and wherein the metal of the first and second metals is the same as the metal of the high-k metal oxide dielectric layer.
11. The semiconductor structure of claim 10 , wherein the bottle-shaped opening has a lower portion of a first width, wl, and an upper portion of a second width, w 2 , wherein w 2 is less than w 1 .
12. The semiconductor structure of claim 11 , wherein w 1 is at least 1.5 times greater than the w 2 .
13. The semiconductor structure of claim 11 , wherein w 1 is from 15 nm to 1500 nm, and w 2 is from 10 nm to 1000 nm.
14. The semiconductor structure of claim 10 , wherein the first metal and the second metal are selected from a group consisting of niobium (Nb), titanium (Ti), zirconium (Zr), hafnium (Hf), and tantalum (Ta).
15. The semiconductor structure of claim 10 , wherein the first metal and the second metal are composed of Nb nitride and the high-k metal oxide dielectric layer is composed of niobium oxide.
16. The semiconductor structure of claim 10 , wherein the lower electrode layer has a thickness from 5 nm to 50 nm.
17. The semiconductor structure of claim 10 , wherein the high-k metal oxide dielectric layer has a thickness from 1 nm to 20 nm.
18. The semiconductor structure of claim 10 , wherein upper electrode layer has a thickness from 5 nm to 50 nm.