Multi-level phase change memory
View Patent ↗A phase change memory may be formed which is amenable to multilevel programming. The phase change material may be formed with a lateral extent which does not exceed the lateral extent of an underlying heater. As a result, the possibility of current bypassing the amorphous phase change material in the reset state is reduced, reducing the programming current that is necessary to prevent this situation. In addition, a more controllable multilevel phase change memory may be formed in some embodiments.
1. A phase change memory comprising:
a substrate;
a dielectric layer over said substrate;
a pore extending completely through said dielectric layer;
a non-conductive sidewall spacer in said pore;
a heater formed in said pore over said substrate; and
a phase change material formed entirely within said pore over said heater.
2. The memory of claim 1 wherein said phase change material has a height less than 750 Angstroms.
3. The memory of claim 1 wherein said phase change material has a height of about 600 Angstroms.
4. The memory of claim 1 wherein said memory is a multilevel phase change memory.
5. The memory of claim 1 wherein said heater is taller than said phase change material.
6. The memory of claim 5 wherein the width of said phase change material and said heater are the same.
7. The memory of claim 1 including a first electrode coupled to said heater and a second electrode over and coupled to said phase change material.
8. The memory of claim 1 including a pair of dielectric layers over a substrate, said dielectric layers having said pore formed therethrough.