Multilayer electrode structures including capacitor structures having aluminum oxide diffusion barriers

Abstract

A multilayer electrode structure has a conductive layer including aluminum, an oxide layer formed on the conductive layer, and an oxygen diffusion barrier layer. The oxide layer includes zirconium oxide and/or titanium oxide. The oxygen diffusion barrier layer is formed at an interface between the conductive layer and the oxide layer by re-oxidizing the oxide layer. The oxygen diffusion barrier layer includes aluminum oxide.

1 . A multilayer electrode structure comprising:
 a conductive layer including aluminum;   an oxide layer on the conductive layer, the oxide layer including zirconium oxide and/or titanium oxide; and   an oxygen diffusion barrier layer between the conductive layer and the oxide layer, the oxygen diffusion barrier layer including aluminum oxide.   
   
   
       2 . The multilayer electrode structure of  claim 1 , wherein the oxygen diffusion barrier layer has thickness between about 2 Å and about 5 Å. 
   
   
       3 . The multilayer electrode structure of  claim 1 , wherein the conductive layer includes titanium aluminum nitride and/or tantalum aluminum nitride. 
   
   
       4 . The multilayer electrode structure of  claim 1 , wherein a thickness ratio between the oxide layer and the oxygen diffusion barrier layer is in a range of about 15:1 to about 25:1. 
   
   
       5 . The multilayer electrode structure of  claim 1  wherein the oxygen diffusion barrier layer is directly on the conductive layer, and the oxide layer is directly on the oxygen diffusion barrier layer. 
   
   
       6 . The multilayer electrode structure of  claim 1  wherein the oxygen diffusion barrier layer is formed by re-oxidizing the oxide layer. 
   
   
       7 . The multilayer electrode structure of  claim 1  further comprising:
 a plate electrode on the dielectric layer, to provide a capacitor.   
   
   
       8 . The multilayer electrode structure of  claim 7 , wherein the plate electrode includes radium or titanium nitride.