Forming phase change memories
View Patent ↗Phase change memories may exhibit improved properties and lower cost in some cases by forming the phase change material layers in a planar configuration. A heater may be provided below the phase change material layers to appropriately heat the material to induce the phase changes. The heater may be coupled to an appropriate conductor.
1. A phase change memory comprising:
a planar phase change material;
an insulating layer having a thermal conductivity at least four times less than oxide;
a heater in said insulating layer and under said planar phase change material; and
a conductor coupled to said heater.
2. The phase change memory of claim 1 including a semiconductor substrate, said planar phase change material arranged over said semiconductor substrate and extending parallel to said substrate.
3. The phase change memory of claim 2 including an insulator between said semiconductor substrate and said planar phase change material.
4. The phase change memory of claim 3 including a passage extending through said insulator.
5. The phase change memory of claim 4 wherein said heater is in said passage.
6. The phase change memory of claim 5 wherein said conductor is in said passage under said heater and electrically coupled to said heater.
7. The phase change memory of claim 6 wherein said passage includes a sidewall spacer.
8. The phase change memory of claim 1 wherein said conductor has a width, said heater has a width, and the width of said conductor is substantially the same width as the width of said heater.
9. The phase change memory of claim 1 wherein said conductor is cup-shaped with a central opening.
10. The phase change memory of claim 9 including an insulator in said central opening.
11. The phase change memory of claim 10 wherein said heater is ring-shaped.
12. The phase change memory of claim 1 wherein said insulating layer includes a xerogel.
13. The phase change memory of claim 1 wherein said conductor is wider than said heater.
14. A phase change memory comprising:
a planar phase change material;
a heater under said planar phase change material;
a conductor coupled to said heater; and
a carbon containing layer between said planar phase change material and said heater.
15. The phase change memory of claim 14 including forming said heater in an insulating layer that has a thermal conductivity at least four times less than oxide.
16. The phase change memory of claim 15 wherein said insulating layer includes a xerogel.