Phase change material variable capacitor
View Patent ↗A method of manufacturing a variable capacitor includes forming a capacitor conductor. The method also includes forming a phase change material adjacent the capacitor conductor. The method further includes forming a first contact on the capacitor conductor. The method additionally includes forming a second contact and a third contact on the phase change material.
1. A variable capacitor, comprising:
a capacitor conductor;
a phase change material adjacent the capacitor conductor;
a first contact on the phase change material; and
a second contact on the phase change material,
wherein a conduction path between the first contact and the second contact includes at least a portion of the phase change material and excludes the capacitor conductor.
2. The variable capacitor of claim 1 , further comprising a dielectric between the phase change material and the capacitor conductor.
3. The variable capacitor of claim 1 , wherein the capacitor conductor comprises an upper capacitor conductor of the variable capacitor, the variable capacitor further comprising:
an upper dielectric between an upper side of the phase change material and the upper capacitor conductor;
a lower capacitor conductor; and
a lower dielectric between a lower side of the phase change material and the lower capacitor conductor.
4. The variable capacitor of claim 3 , further comprising:
a third contact on the upper capacitor conductor; and
a fourth contact on the lower capacitor conductor.
5. The variable capacitor of claim 1 , wherein the phase change material is composed of a material that is selectively changeable between an amorphous phase and a crystalline phase.
6. The variable capacitor of claim 1 , wherein the phase change material is composed of a material that is selectively changeable between a first phase having a high resistivity and a second phase having a low resistivity.
7. The variable capacitor of claim 1 , wherein the phase change material comprises a chalcogenide material.
8. The variable capacitor of claim 1 , wherein the capacitor conductor and the phase change material are formed in interlevel dielectric layers over a substrate.
9. The variable capacitor of claim 1 , further comprising a control device connected to the first contact on the phase change material and the second contact on the phase change material.
10. The variable capacitor of claim 9 , wherein the control device is configured to selectively apply a current through the conduction path between the first contact and the second contact for a predefined amount of time.
11. The variable capacitor of claim 10 , wherein a magnitude of the current and the predefined amount of time are selected to one of: set the phase change material to a crystalline phase and reset the phase change material to an amorphous phase.
12. The variable capacitor of claim 9 , wherein the control device is configured to selectively generate a voltage differential between the first contact and the second contact for a determined time, the voltage differential configured to drive a current through the conduction path between the first contact and the second contact for the determined time.
13. A method of manufacturing a variable capacitor, comprising:
forming a capacitor conductor;
forming a phase change material that is selectively changeable between one of a first phase and a second phase;
forming a first contact on the capacitor conductor; and
forming a second contact and a third contact on the phase change material,
wherein the variable capacitor has a first capacitance when the phase change material is in the first phase and a second capacitance, different from the first capacitance, when the phase change material is in the second phase.
14. The method of claim 13 , further comprising forming a capacitor dielectric between the capacitor conductor and the phase change material.
15. The method of claim 14 , further comprising:
forming an other capacitor conductor; and
forming an other capacitor dielectric between the other capacitor conductor and the phase change material.
16. The method of claim 13 , further comprising forming a control device configured to selectively change the phase change material to one of the first phase and the second phase.
17. The method of claim 16 , wherein the control device is connected to the second contact and the third contact on the phase change material.
18. The method of claim 13 , wherein:
the capacitor conductor and the phase change material are formed in interlevel dielectric layers over a substrate;
the phase change material comprises a chalcogenide material;
the first phase is a high resistivity amorphous phase; and
the second phase is a low resistivity crystalline phase.
19. A variable capacitor device, comprising:
a first layer comprising a phase change material;
a plurality of electrode layers, wherein each electrode layer comprises a conductor material and is coupled to a respective side of the first layer by a respective dielectric layer; and
a plurality of contacts, wherein each contact is coupled to the phase change material at a respective location on the first layer and is insulated from the conductor material of the electrode layers.
20. The variable capacitor device of claim 19 , further comprising circuitry configured to selectively control a phase of the phase change material within the first layer by adjusting a voltage potential on one or more of the plurality of contacts.