Phase change memory cell with high read margin at low power operation

1. A memory cell device comprising:

a first electrode;

resistivity changing material adjacent the first electrode;

a second electrode adjacent the resistivity changing material;

a diffusion barrier adjacent the resistivity changing material and directly contracting the first electrode and the second electrode; and

isolation material adjacent the diffusion barrier for thermally isolating the resistivity changing material, the isolation material comprising a porous dielectric oxide film having a thermal conductively between 0.1 and 0.8 W/mk,

wherein the diffusion barrier prevents diffusion of the resistivity changing material into the isolation material.

2. The memory cell device of claim 1 , wherein the resistivity changing material comprises a chalcogenide.

3. The memory cell device of claim 1 , wherein the diffusion barrier comprises SiN.

4. The memory cell device of claim 1 , wherein the dielectric material limits heat leakage from the resistivity changing material.

5. The memory cell device of claim 1 , wherein the diffusion barrier laterally surrounds the resistivity changing material.

6. The memory cell device of claim 1 , wherein the first electrode comprises one of a tungsten plug and a copper plug.

7. The memory cell device of claim 1 , further comprising:

first insulation material laterally surrounding the first electrode; and

second insulation material laterally surrounding the second electrode,

wherein the diffusion barrier directly contacts a face of one of the first insulation material and the second insulation material, the face perpendicular to a current path through the resistivity changing material.

8. The memory cell device of claim 1 , wherein a width of the resistivity changing material is less than a width of the first electrode and a width of the second electrode.

9. A memory cell device comprising:

a first electrode;

phase-change material adjacent the first electrode;

a second electrode adjacent the phase-change material;

first means adjacent the phase-change material for thermally isolating the phase-change material; and

second means adjacent the first means and directly contacting the first electrode and the second electrode for preventing diffusion of the phase-change material into the first means,

wherein the first means comprises a dielectric material that limits heat leakage from the phase-change material, and

wherein the dielectric material comprises a porous oxide film having a thermal conductivity between 0.1 and 0.8 W/mk.

10. The memory cell device of claim 9 , wherein the phase-change material comprises a chalcogenide.

11. The memory cell device of claim 9 , wherein the second means comprises SiN.

12. The memory cell device of claim 9 , wherein the first means laterally surrounds the phase-change material.

13. An integrated circuit comprising:

a first electrode;

a second electrode;

resistivity changing material between the first electrode and the second electrode;

a diffusion barrier laterally surrounding the resistivity changing material and directly contacting the first electrode and the second electrode; and

isolation material adjacent the diffusion barrier for thermally isolating the resistivity changing material,

wherein the diffusion barrier prevents diffusion of the resistivity changing material into the isolation material,

wherein the isolation material comprises a dielectric material that limits heat leakage from the resistivity changing material, and

wherein the dielectric material comprises a porous oxide film having a thermal conductivity between 0.1 and 0.8 W/mk.

14. The integrated circuit of claim 13 , wherein the resistivity changing material comprises a phase-change material.

15. The integrated circuit of claim 14 , wherein the phase-change material comprises a chalcogenide.

16. The integrated circuit of claim 13 , wherein the diffusion barrier comprises SiN.

17. The integrated circuit of claim 13 , wherein the isolation material laterally surrounds the resistivity changing material.

18. An integrated circuit comprising:

a first electrode;

phase-change material adjacent the first electrode;

a second electrode adjacent the phase-change material;

isolation material for thermally isolating the phase-change material, the isolation material comprising a porous dielectric oxide film having a thermal conductivity between 0.1 and 0.8 W/mk; and

a diffusion barrier for preventing diffusion of the phase-change material into the isolation material,

wherein one of the first electrode and the second electrode directly contacts the isolation material.