Thin-film capacitor with a field modification layer
View Patent ↗A method for forming a capacitor includes providing a metal-containing bottom electrode, forming a capacitor insulator over the metal-containing bottom electrode, forming a metal-containing top electrode over the capacitor insulator, and forming a dielectric-containing field modification layer over the capacitor insulator and at least partially surrounding the metal-containing top electrode. Forming the dielectric-containing field modification layer may include oxidizing a sidewall of the metal-containing field modification layer. A barrier layer may be formed over the capacitor insulator prior to forming the metal-containing top electrode.
1. A capacitor comprising:
a workpiece having a first electrode;
a capacitor insulator layer overlying the first electrode;
a barrier layer overlying the capacitor insulator layer, wherein the barrier layer comprises an insulating material;
a second electrode overlying the barrier layer, wherein:
the second electrode includes a metal-containing layer;
the second electrode has a sidewall, wherein each of the capacitor insulating layer and the barrier layer includes a continuous portion that underlies the second electrode and extends to a location spaced-apart and not covered by the second electrode; and
a dielectric-containing field modification layer overlying the capacitor insulator and barrier layers and at least partially surrounding the second electrode, wherein the dielectric-containing field modification layer includes an oxide of the metal-containing layer and is spaced apart from the capacitor insulating layer by the barrier layer.
2. The capacitor of claim 1 , wherein the barrier layer comprises an etch-stop layer.
3. The capacitor of claim 2 , wherein the barrier layer comprises an oxide.
4. The capacitor of claim 3 , wherein the barrier layer comprises hafnium oxide or aluminum oxide.
5. The capacitor of claim 1 , wherein the barrier layer has a thickness in a range of 10 to 100 Angstroms.
6. The capacitor of claim 1 , wherein the dielectric-containing field modification layer comprises tantalum pentoxide, tantalum oxynitride, titanium oxide, titanium oxynitride, aluminum oxide, or aluminum oxynitride.
7. The capacitor of claim 6 , wherein the capacitor insulator layer comprises silicon dioxide, silicon nitride, tantalum pentoxide, or hafnium oxide.
8. The capacitor of claim 7 , wherein the capacitor has a non-planar structure.
9. The capacitor of claim 1 , wherein the capacitor has a planar structure.
10. The capacitor of claim 1 , wherein the barrier layer abuts the second electrode.
11. The capacitor of claim 1 , wherein the dielectric-containing field modification layer lies along a sidewall of the second electrode and not over the second electrode.
12. The capacitor of claim 1 , wherein the dielectric-containing field modification layer has a thickness of at least 100 Angstroms.
13. The capacitor of claim 1 , wherein an angle is defined by a bottom surface of the second electrode and an immediately adjacent sidewall of the second electrode, wherein the angle is greater than 90 degrees.
14. A capacitor comprising:
a workpiece having a first electrode;
a capacitor insulator layer overlying the first electrode;
a barrier layer overlying the capacitor insulator layer, wherein the barrier layer comprises an insulating material;
a second electrode overlying the barrier layer, wherein the second electrode includes a metal-containing layer, and wherein an angle is defined by a bottom surface of the second electrode and an immediately adjacent sidewall of the second electrode, wherein the angle is greater than 90 degrees; and
a dielectric-containing field modification layer overlying the capacitor insulator and barrier layers and at least partially surrounding the second electrode, wherein the dielectric-containing field modification layer includes an oxide of the metal-containing layer and is spaced apart from the capacitor insulating layer by the barrier layer.
15. The capacitor of claim 14 , wherein the dielectric-containing field modification layer comprises tantalum pentoxide, tantalum oxynitride, titanium oxide, titanium oxynitride, aluminum oxide, or aluminum oxynitride.
16. The capacitor of claim 15 , wherein the capacitor insulator layer comprises silicon dioxide, silicon nitride, tantalum pentoxide, or hafnium oxide.
17. The capacitor of claim 16 , wherein the barrier layer comprises hafnium oxide or aluminum oxide.
18. The capacitor of claim 14 , wherein the dielectric-containing field modification layer does not overlie the second electrode.
19. The capacitor of claim 14 , wherein:
the barrier layer abuts the capacitor insulating layer, the second electrode, and the dielectric-containing field modification layer;
the capacitor insulating layer is spaced apart from the second electrode and the dielectric-containing field modification layer.
20. The capacitor of claim 14 , wherein the second electrode has a sidewall, wherein each of the capacitor insulating layer and the barrier layer includes a continuous portion that underlies the second electrode and extends to a location spaced-apart and not covered by the second electrode.