Method for making tapered opening for programmable resistance memory element
View Patent ↗A method for making a tapered opening. The defined tapered opening is useful for the fabrication of programmable resistance memory elements. The programmable resistance memory material may be a chalcogenide.
1. A method of fabricating a second opening, comprising:
providing a layer of a first material;
forming a layer of a second material over said layer of said first material;
forming a layer of a third material over said layer of said second material;
forming a first opening in said layer of said third material to expose said second material, said first opening not extending into substantially any of said layer of said second material;
forming a sidewall spacer of a fourth material on a sidewall surface of said first opening;
removing a first portion of said layer of said second material to form a recess in said layer of said second material, said recess does not expose said first material, said recess having a bottom surface consisting essentially of the same material as said first portion of said second material; and
removing a second portion of said second material to form said second opening in said layer of said second material exposing said first material.
2. The method of claim 1 , wherein said second opening is a hole.
3. The method of claim 1 , wherein said second opening is a trench.
4. The method of claim 1 , wherein said third material and said fourth material are the same material.
5. The method of claim 1 , wherein said first material is a conductive material.
6. The method of claim 1 , wherein said second material is a dielectric.
7. The method of claim 6 , wherein said dielectric comprises an oxide or a nitride.
8. The method of claim 1 , wherein said third material and said fourth material are polysilicon.
9. The method of claim 1 , wherein said third material and said fourth material are a dielectric.
10. The method of claim 9 , wherein said dielectric is an oxide or a nitride.
11. The method of claim 1 , wherein the ratio of the depth of said recess of said second layer to the thickness of said second layer is less than 0.5.
12. The method of claim 1 , further comprising, after said recess is formed, removing at least a portion of said sidewall spacer so as to decrease the thickness of said spacer.
13. The method of claim 1 , further comprising removing at least a portion of said sidewall spacer so as to decrease the thickness of said spacer while removing said second portion of said second material.
14. The method of claim 13 , wherein the rate of removal of said sidewall spacer is greater than the rate of removal of said second portion of said second material.
15. The method of claim 1 , further comprising removing a third portion of said second material from a sidewall surface of said recess while removing said second portion of said second material.
16. The method of claim 13 , further comprising removing a third portion of said second material from a sidewall surface of said recess while removing said second portion of said second material.
17. A method of fabricating a memory element, comprising:
providing a layer of a first material;
forming a layer of said second material over said layer of said first material;
forming a layer of a third material over said layer of said second material; forming a first opening in said layer of said third material to expose said second material, said first opening not extending into substantially any of said layer of said second material;
forming a sidewall spacer of a fourth material on a sidewall surface of said first opening;
removing a first portion of said second material to form a recess in said layer of said second material, said recess does not expose said first material, said recess having a bottom surface consisting essentially of the same material as said first portion of said second material;
removing a second portion of said layer of said second material to form a second opening in said layer of said second material exposing said first material; and
forming a programmable resistance material in said second opening of said second material.
18. The method of claim 17 , wherein said second opening in said layer of said second material is a hole.
19. The method of claim 17 , wherein said second opening in said layer of said second material is a trench.
20. The method of claim 17 , wherein said third material and said fourth material are the same material.
21. The method of claim 17 , wherein said first material is a conductive material.
22. The method of claim 17 , wherein said second material is a dielectric material.
23. The method of claim 22 , wherein said dielectric is an oxide or a nitride.
24. The method of claim 17 , wherein said third material and said fourth material are polysilicon.
25. The method of claim 17 , wherein said third material and said fourth material are a dielectric.
26. The method of claim 25 , wherein said dielectric is an oxide or a nitride.
27. The method of claim 17 , wherein the ratio of the depth of said recess of said second layer to the thickness of said second layer is less thin 0.5.
28. The method of claim 17 , further comprising forming a conductive material over said programmable resistance material after forming said programmable resistance material.
29. The method of claim 17 , wherein said programmable resistance material is in direct contact with said first material.
30. The method of claim 17 , wherein said programmable resistance material is a phase-change material.
31. The method of claim 17 , further comprising, after said recess is formed, removing at least a portion of said sidewall spacer so as to decrease the thickness of said spacer.
32. The method of claim 17 , further comprising removing at least a portion of said sidewall spacer so as to decrease the thickness of said spacer while removing said second portion of said second material.
33. The method of claim 32 , wherein the rate of removal of said sidewall spacer is greater than the rate of removal of said second portion of said second material.
34. The method of claim 17 , further comprising removing a third portion of said second material from a sidewall surface of said recess while removing said second portion of said second material.
35. The method of claim 32 , further comprising removing a third portion of said second material from a sidewall surface of said recess while removing said second portion of said second material.
36. A method of fabricating an electrical device, comprising:
providing a layer of a first material;
forming a layer of said second material over said layer of said first material;
forming a layer of a third material over said layer of said second material;
forming a first opening in said layer of said third material to expose said second material, said first opening not extending into substantially any of said layer of said second material;
forming a sidewall spacer of a fourth material on a sidewall surface of said first opening;
removing a first portion of said second material to form a recess in said layer of said second material, said recess does not expose said first material, said recess having a bottom surface consisting essentially of the same material as said first portion of said second material;
removing a second portion of said layer of said second material to form a second opening in said layer of said second material exposing said first material; and
forming a chalcogenide material in said second opening of said second material.
37. The method of claim 36 , further comprising, after said recess is formed, removing at least a portion of said sidewall spacer so as to decrease the thickness of said spacer.
38. The method of claim 36 , further comprising removing at least a portion of said sidewall spacer so as to decrease the thickness of said spacer while removing said second portion of said second material.
39. The method of claim 38 , wherein the rate of removal of said sidewall spacer is greater than the rate of removal of said second portion of said second material.
40. The method of claim 36 , further comprising removing a third portion of said second material from a sidewall surface of said recess while removing said second portion of said second material.
41. The method of claim 38 , further comprising removing a third portion of said second material from a sidewall surface of said recess while removing said second portion of said second material.