Phase change memory with concentric ring-shaped heater
A ring-shaped heater, system, and method to gradually change the conductance of the phase change memory through a concentric ring-shaped heater. The system may include a phase change memory. The phase change memory may include a bottom electrode. The phase change memory may also include a ring-shaped heater patterned on top of the bottom electrode, the ring-shaped heater including: a plurality of concentric conductive heating layers, and a plurality of insulator spacers, where each insulator spacer separates each conductive heating layer. The phase change memory may also include a phase change material proximately connected to the ring-shaped heater. The phase change memory may also include a top electrode proximately connected to the phase change material.
1. A device comprising:
a ring-shaped heater comprising:
a plurality of concentric conductive heating layers; and
a plurality of insulator spacers, wherein each insulator spacer separates each of the plurality of concentric conductive heating layers, and one insulator spacer of the plurality of insulator spacers is an insulator core that is concentrically surrounded by alternating layers of the plurality of concentric conductive heating layers and a remainder of the plurality of insulator spacers;
a phase change material proximately connected to the ring-shaped heater;
a top electrode proximately connected to the phase change material;
a bottom electrode; and
a conductive stud located at a bottom of the ring-shaped heater and in contact with the bottom electrode,
wherein the plurality of concentric conductive heating layers branch from the conductive stud and connect to the bottom electrode through the conductive stud.
2. The device of claim 1 , wherein one or more of the concentric conductive heating layers, from the plurality of concentric conductive heating layers, have differing thicknesses.
3. The device of claim 1 , wherein one or more of the concentric conductive heating layers, from the plurality of concentric conductive heating layers, have a different composition.
4. The device of claim 1 , wherein one or more of the concentric conductive heating layers, from the plurality of concentric conductive heating layers, comprise titanium nitride.
5. The device of claim 1 , wherein one or more of the insulator spacers, from the plurality of insulator spacers, comprise at least one of silicon nitride and silicon oxide.
6. The device of claim 1 , wherein lengths of the plurality of concentric conductive heating layers are tuned to achieve different resistances.
7. A system comprising:
a phase change memory, the phase change memory comprising:
a bottom electrode;
a ring-shaped heater patterned on the bottom electrode, the ring-shaped heater comprising:
a plurality of concentric conductive heating layers; and
a plurality of insulator spacers, wherein each insulator spacer separates each of the plurality of concentric conductive heating layers, and one insulator spacer of the plurality of insulator spacers is an insulator core that is concentrically surrounded by alternating layers of the plurality of concentric conductive heating layers and a remainder of the plurality of insulator spacers,
a phase change material proximately connected to the ring-shaped heater; and
a top electrode proximately connected to the phase change material; and
a conductive stud located at a bottom of the ring-shaped heater and in contact with the bottom electrode,
wherein the plurality of concentric conductive heating layers branch from the conductive stud and connect to the bottom electrode through the conductive stud.
8. The system of claim 7 , wherein one or more of the concentric conductive heating layers, from the plurality of concentric conductive heating layers, have a different thickness.
9. The system of claim 7 , wherein one or more of the concentric conductive heating layers, from the plurality of concentric conductive heating layers, have a different composition.
10. The system of claim 7 , wherein the plurality of insulator spacers separate side portions of each of the plurality of concentric conductive heating layers, and wherein each of the plurality of concentric conductive heating layers has contact with one or more of the plurality of concentric conductive heating layers on the bottom of the ring-shaped heater.
11. The system of claim 7 , wherein:
one or more of the concentric conductive heating layers, from the plurality of concentric conductive heating layers, have different levels of conductance; and
the phase change material comprises amorphous phases and crystalline phases based on the different levels of conductance of the one or more of the concentric conductive heating layers.
12. The system of claim 7 , further comprising an array of ring-shaped heaters.
13. The system of claim 7 , wherein current passes through each of the plurality of concentric conductive heating layers, resulting in the plurality of concentric conductive heating layers executed in parallel.