Electrically programmable memory element with improved contacts

1. An electrically operated, directly overwritable, single-cell memory element, comprising:

a phase-change memory material;

a first electrical contact, said first contact being a first thin-film layer having a sidewall electrically coupled to said memory material; and

a second electrical contact electrically coupled to said memory material, said second contact spacedly disposed from said first electrical contact,

wherein said sidewall of said first thin-film layer at least partially encircles said memory material.

2. The memory element of claim 1 , wherein said second electrical contact is a second thin-film layer having a sidewall electrically coupled to said memory material.

3. The memory element of claim 1 , wherein the height of the sidewall of said first thin-film layer corresponds to the thickness of said first thin-film layer.

4. The memory element of claim 2 , wherein the height of the sidewall of said second thin-film layer corresponds to the thickness of said second thin-film layer.

5. The memory element of claim 1 , wherein said first thin-film layer and said memory material have an area of contact proportional to the thickness of said first thin-film layer.

6. The memory element of claim 2 , wherein said second thin-film layer and said memory material have an area of contact proportional to the thickness of said second conductive layer.

7. The memory element of claim 1 , wherein the sidewall of said first thin-film layer being substantially perpendicular to a substrate of said memory element.

8. The memory element of claim 2 , wherein the sidewall of said second thin-film layer being substantially perpendicular to a substrate of said memory element.

9. The memory element of claim 1 , wherein said phase-change memory material comprises a chalcogen element.

10. The memory element of claim 7 , wherein said phase-change memory material comprises a chalcogen element.

11. The memory element of claim 1 , wherein a dielectric material is disposed between said first electrical contact and said second electrical contact.

12. The memory element of claim 1 , wherein essentially all communication between said first electrical contact and said memory material is through said sidewall of said first thin-film layer.

13. The memory element of claim 2 , wherein essentially all communication between said second electrical contact and said memory material is through said sidewall of said second thin-film layer.

14. The memory element of claim 1 , wherein said first electrical contact comprises a conductive material.

15. The memory element of claim 1 , wherein said second electrical contact comprises a conductive material.

16. The memory element of claim 2 , wherein the sidewall of said second thin-film layer at least partially encircles said memory material.

17. The memory element of claim 1 , wherein said first thin-film layer has a thickness between 50 Angstroms and 500 Angstroms.

18. The memory element of claim 2 , wherein said second thin-film layer has a thickness between 50 Angstroms and 500 Arlgstroms.

19. The memory element of claim 1 , wherein said memory element is electrically programmable to at least three resistance values.

20. The memory element of claim 1 , wherein said sidewall of said first thin-film layer has a dimension of less than 500 Angstroms.

21. The memory element of claim 20 , wherein said dimension is a height of said sidewall of said first thin-film layer.

22. The memory element of claim 2 , wherein said sidewall of second thin-film layer has a dimension of less than 500 Angstroms.

23. The memory element of claim 22 , wherein said dimension is a height of said sidewall of said second thin-film layer.

24. The memory element of claim 1 , wherein said first thin-film layer has a thickness of less than 500 Angstroms.

25. The memory element of claim 2 , wherein said second thin-film layer has a thickness of less than 500 Angstroms.