Varactors including interconnect layers

1. A varactor comprising:

a substrate;

a bottom electrode positioned on a surface of said substrate;

a tunable dielectric material positioned adjacent to and extending over said bottom electrode forming a step and in contact with a top electrode;

an interconnect layer comprising first and second portions, wherein the first portion is in contact with said bottom electrode and said tunable dielectric, and wherein the second portion is in contact with said top electrode and the tunable dielectric.

2. The varactor of claim 1 , wherein at least one electrode contains multi metallic layers.

3. The varactor of claim 1 , wherein all electrodes contains multi metallic layers.

4. The varactor of claim 1 , wherein the first and second portions of the interconnect layer have an encapsulation layer formed therebetween.

5. The varactor of claim 1 , wherein a dielectric interlayer is positioned between the second portion of the interconnect layer and the tunable dielectric.

6. The varactor of claim 1 , wherein a dielectric interlayer is positioned between the second portion of the interconnect layer and the top electrode.

7. The varactor of claim 1 , further comprising an adhesion layer positioned between said bottom electrode and said substrate; or between said bottom electrode and said tunable dielectric; or between said tunable dielectric and said top electrode or said interconnect layer; or between said top electrode and said interconnect layer.

8. A varactor comprising:

a substrate;

a plurality of bottom electrodes positioned on a surface of the substrate separated to form a gap therein;

a tunable dielectric material positioned on the surface of the substrate and within said gap, said tunable dielectric at least partially overlaying said plurality of electrodes;

a top electrode in contact with said tunable dielectric; and

an adhesion layer between said bottom electrode and said substrate; or between said bottom electrode and said tunable dielectric materials; or between said tunable dielectric and said top electrode or said interconnect layer; or between said top electrode and said interconnect layer.

9. The varactor of claim 8 , wherein at least one electrode contains multi metallic layers.

10. The varactor of claim 8 , wherein all electrodes contain multi metallic layers.

11. A varactor comprising:

a substrate;

a plurality of bottom electrodes positioned on a surface of the substrate separated to form a gap therein;

a tunable dielectric material positioned on the surface of the substrate and within said gap, said tunable dielectric at least partially overlaying said plurality of electrodes;

a top electrode in contact with said tunable dielectric; and

a plurality of interconnects on a surface of said plurality of electrodes enabling a connection to a voltage source.

12. The varactor of claim 11 , wherein at least one electrode contains multi metallic layers.

13. The varactor of claim 11 , wherein all electrodes contains multi metallic layers.

14. The varactor of claim 11 , wherein an encapsulation layer is formed between the interconnect layers and the top electrode.

15. The varactor of claim 11 , wherein a dielectric interlayer is positioned between one of the interconnect layers and the top electrode.

16. The varactor of claim 11 , wherein an encapsulation layer is formed over a portion of the interconnect layers, the top electrode and a dielectric interlayer.

17. The varactor of claim 11 , wherein the top electrode is a pair of top electrodes with a dielectric interlayer therebetween.

18. The varactor of claim 11 , further comprising an adhesion layer positioned between said bottom electrode and said substrate; or between said bottom electrode and said tunable dielectric materials; or between said tunable dielectric material and at least one of said interconnects; or between said tunable dielectric and said top electrode or at least one of said interconnects; or between said top electrode and at least one of said interconnects.