Device and method for inhibiting oxidation of contact plugs in ferroelectric capacitor devices

1. A method for fabricating a device comprising the steps of:

forming a substrate;

forming a contact plug through said substrate;

forming an electrically insulating layer on said substrate;

forming a first electrode on said electrically insulating layer;

forming a dielectric layer on said first electrode;

forming a second electrode on said dielectric layer;

and then electrically connecting said first electrode to said plug through said electrically insulating layer.

2. The method of claim 1 , wherein the step of forming an electrically insulating layer comprises forming an electrically insulating layer resistant to oxygen diffusion.

3. The method of claim 1 , further comprising the step of etching said second electrode and said dielectric layer to divide the device into a number of devices having a common first electrode prior to electrically connecting said first electrode to said plug.

4. The method of claim 3 , further comprising the step of forming one or more encapsulation layers on said second electrode and dielectric layer after the step of etching said second electrode and said dielectric layer.

5. The method of claim 4 , further comprising the step of forming a hardmask over said one or more encapsulation layers to define said first electrode.

6. The method of claim 5 , further comprising the step of etching said first electrode according to said hardmask after the step of forming said hardmask.

7. The method of claim 6 , further comprising the step of forming one or more cover layers over said hardmask after the step of etching said first electrode, said one or more cover layers extending to said electrically insulating layer.

8. The method of claim 6 , further comprising the step of forming an interlayer dielectric layer on said one or more cover layers.

9. The method of claim 8 , further comprising the step of planarising said interlayer dielectric layer.

10. The method in claim 9 , further comprising the step of forming a contact window to said first electrode after the step of planarizing said interlayer dielectric layer.

11. The method of claim 10 , further comprising the step of depositing a contact liner in said contact window.

12. The method of claim 11 , further comprising the step of depositing in said contact window a metal insert after the step of depositing said contact liner in said contact window, to establish electrical contact between said first electrode and said plug.

13. The method of claim 12 , further comprising the step of etching said contact liner and said metal insert from said interlayer dielectric to said first electrode.

14. The method of claim 13 , further comprising the step of depositing a further cover layer to line said contact window and surface of said metal insert after the step of etching said contact liner and said metal insert.

15. The method of claim 14 , further comprising the steps of applying a further interlayer dielectric layer over said further cover layer after the step of depositing said further cover layer.

16. The method of claim 15 , further comprising the step of planarizing said further interlayer dielectric layer.

17. The method of claim 16 , further comprising the step of forming one or more contact windows to second electrode after the step of planarizing said further interlayer dielectric layer.

18. The method according to claim 1 , wherein the step of forming a dielectric layer on said first electrode comprises forming a ferroelectric layer on said first electrode.

19. A device formed according to the method of claim 1 .

20. A ferroelectric capacitor device formed according to the method of claim 1 .

21. A Random Access Memory device comprising one or more devices formed according to the method of claim 1 .