Reducing shunts in memories with phase-change material
View Patent ↗A memory cell may include a phase-change material. Adhesion between the phase-change material and a dielectric or other substrate may be enhanced by using an adhesion enhancing interfacial layer. Conduction past the phase-change material through the interfacial layer may be reduced by providing a discontinuity or other feature that reduces or prevents conduction along said interfacial layer.
1. A method comprising:
forming a passage through a dielectric layer;
covering said passage with an adhesion promoting material;
creating an electrical discontinuity in said adhesion promoting material along said passage; and
forming a phase-change material in said passage.
2. The method of claim 1 including forming a dielectric layer over a contact layer and forming said passage through said dielectric layer to said contact layer.
3. The method of claim 2 including covering said passage with an adhesion promoting material that is conductive.
4. The method of claim 1 wherein creating an electrical discontinuity includes forming an opening in said adhesion promoting material.
5. The method of claim 4 wherein forming a passage includes forming a dielectric having at least two discrete layers and forming the passage through said layers.
6. The method of claim 5 including forming a substantially vertically extending passage through said layers and then forming a lateral extension in said passage into one of said layers.
7. The method of claim 6 including forming said lateral extension by selectively isotropically etching one of said layers.
8. The method of claim 7 wherein forming a passage includes forming a dielectric with three layers including a middle layer.
9. The method of claim 8 including selectively isotropically etching the middle layer of said three layers.
10. A method comprising:
forming a passage through a dielectric layer;
covering said passage with a conductive material;
preventing conduction along said passage via said conductive material; and
forming a phase-change material in said passage.
11. The method of claim 10 including forming a dielectric layer over a contact layer and forming said passage through said dielectric layer to said contact layer.
12. The method of claim 11 including covering said passage with a conductive material that promotes adhesion between said phase-change material and said dielectric layer.
13. The method of claim 10 wherein preventing conduction along said passage via said conductive material includes creating an electrical discontinuity in said conductive material along said passage.
14. The method of claim 13 wherein forming a passage includes forming a dielectric having at least two discrete layers and forming said passage through said layers.
15. The method of claim 14 including forming a substantially vertically extending passage through said layers and then forming a lateral extension in said passage in one of said layers.
16. The method of claim 15 including forming said lateral extension by selectively isotropically etching one of said layers.
17. The method of claim 16 wherein forming said passage includes forming a dielectric with three layers including a middle layer.
18. The method of claim 17 including selectively isotropically etching the middle layer of said three layers.