Resistive switching device having a protective electrode ring
Embodiments of the invention are directed to a structure that includes a resistive switching device (RSD). The RSD includes a first terminal having an outer sidewall surface; a second terminal; an active region having a switchable conduction state; and a first protective layer on the outer sidewall surface of the first terminal.
1. A structure comprising:
a resistive switching device (RSD) comprising:
a first terminal having an outer sidewall surface;
a second terminal;
an active region having a switchable conduction state;
an undercut region at least partially defined by the outer sidewall surface and a portion of a top surface of the active region; and
a first protective layer within the undercut region.
2. The structure of claim 1 , wherein the first protective layer is on the outer sidewall surface of the first terminal.
3. The structure of claim 2 , further comprising a first via trench formed above the first terminal, wherein the first terminal comprises a first terminal material having a first etch rate to an etching substance used to form the first via trench.
4. The structure of claim 3 , wherein the first protective layer comprises a first protective layer material having a second etch rate to the etching substance used to form the first via trench.
5. The structure of claim 4 , wherein the first etch rate of the first terminal material is greater than the second etch rate of the first protective layer material.
6. The structure of claim 5 further comprising a spacer layer on at least a portion of outer sidewalls of the first protective layer.
7. The structure of claim 6 , wherein the spacer layer comprises a spacer layer material having a third etch rate to the etching substance used to form the first via trench.
8. The structure of claim 7 , wherein the third etch rate of the spacer layer material is greater than the second etch rate of the first protective layer material.
9. The structure of claim 5 further comprising:
a second protective layer formed on outer sidewalls of the second terminal,
wherein the second terminal comprises a second terminal material having a first etch rate to an etching substance used to form the first via trench; and
wherein the second protective layer comprises a second protective layer material having a second etch rate to the etching substance used to form the first via trench.
10. The structure of claim 9 , wherein the first etch rate of the second terminal material is greater than the second etch rate of the second protective layer material.
11. A method of forming a structure, the method comprising:
forming a resistive switching device (RSD) comprising:
a first terminal;
a first terminal undercut region at least partially defined by an outer sidewall surface of the first terminal;
a second terminal;
an active region having a switchable conduction state; and
a first protective layer within the first terminal undercut region.
12. The method of claim 11 , wherein the first protective layer is on the outer sidewall surface of the first terminal.
13. The method of claim 12 further comprising forming a first via trench above the first terminal, wherein the first terminal comprises a first terminal material having a first etch rate to an etching substance used to form the first via trench.
14. The method of claim 13 , wherein the first protective layer comprises a first protective layer material having a second etch rate to the etching substance used to form the first via trench.
15. The method of claim 14 , wherein the first etch rate of the first terminal material is greater than the second etch rate of the first protective layer material.
16. The method of claim 15 further comprising forming a spacer layer on at least a portion of outer sidewalls of the first protective layer.
17. The method of claim 16 , wherein the spacer layer comprises a spacer layer material having a third etch rate to the etching substance used to form the first via trench.
18. The method of claim 17 , wherein the third etch rate of the spacer layer material is greater than the second etch rate of the first protective layer material.
19. The method of claim 15 further comprising:
forming a second protective layer on outer sidewalls of the second terminal,
wherein the second terminal comprises a second terminal material having a first etch rate to an etching substance used to form the first via trench; and
wherein the second protective layer comprises a second protective layer material having a second etch rate to the etching substance used to form the first via trench.
20. The method of claim 19 , wherein the first etch rate of the second terminal material is greater than the second etch rate of the second protective layer material.