Capacitor with high dielectric constant materials and method of making

Abstract

Stabilized capacitors and DRAM cells using high dielectric constant oxide dielectric materials such as Ta 2 O 5 and Ba x Sr (1−x) TiO 3 , and methods of making such capacitors and DRAM cells are provided. A preferred method includes providing a conductive oxide electrode, depositing a first layer of a high dielectric constant oxide dielectric material on the conductive oxide electrode, oxidizing the conductive oxide electrode and the first layer of the high dielectric constant oxide dielectric material under oxidizing conditions, depositing a second layer of the high dielectric constant oxide dielectric material on the first layer of the dielectric, and depositing an upper layer electrode on the second layer of the high dielectric constant oxide dielectric material.

What is claimed is:  
     
         1 . A capacitor comprising an oxidized conductive oxide electrode, an oxidized first layer of a high dielectric constant oxide dielectric material adjacent said oxidized conductive oxide electrode, a second layer of said high dielectric constant oxide dielectric material adjacent said first layer of said high dielectric constant oxide dielectric material, and an upper layer electrode adjacent said second layer of said high dielectric constant oxide dielectric material, wherein said oxidized conductive oxide electrode and said oxidized first layer of said high dielectric constant oxide dielectric material are oxidized prior to depositing said second layer of said high dielectric constant oxide dielectric material oxide dielectric.  
     
     
         2 . A capacitor as claimed in  claim 1  wherein said high dielectric constant oxide dielectric material is selected from the group consisting of Ta 2 O 5  and Ba x Sr (1−x) TiO 3 .  
     
     
         3 . A capacitor as claimed in  claim 1  wherein said oxidized conductive oxide electrode is selected from the group consisting of RuO x  and IrO x .  
     
     
         4 . A capacitor as claimed in  claim 1  wherein said upper layer electrode is selected from the group consisting of RuO x  and IrO x .  
     
     
         5 . A capacitor as claimed in  claim 1  further comprising a gas permeable electrode adjacent said upper layer electrode.  
     
     
         6 . A capacitor as claimed in  claim 5  wherein said gas permeable electrode comprises platinum.  
     
     
         7 . A capacitor as claimed in  claim 1  wherein said first layer of said high dielectric constant oxide dielectric material is between about 20 and about 50 Å thick.  
     
     
         8 . A capacitor comprising an oxidized conductive oxide electrode selected from the group consisting of RuO x  and IrO x , an oxidized first layer of a high dielectric constant oxide dielectric material adjacent to said oxidized conductive oxide layer, a second layer of said high dielectric constant oxide dielectric material adjacent to said first layer of said high dielectric constant oxide dielectric material, and an upper layer electrode selected from the group consisting of RuO x  and IrO x  adjacent said second layer of said high dielectric constant oxide dielectric material, wherein said oxidized conductive oxide electrode and said oxidized first layer of said high dielectric constant oxide dielectric material are oxidized prior to the deposition of said second layer of said high dielectric constant oxide dielectric material.  
     
     
         9 . A capacitor as claimed in  claim 8  wherein said high dielectric constant oxide dielectric material is selected from the group consisting of Ta 2 O 5  and Ba x Sr (1−x) TiO 3 .  
     
     
         10 . A capacitor as claimed in  claim 8  wherein said first layer of said high dielectric constant oxide dielectric material is between about 20 and about 50 Å thick.  
     
     
         11 . A capacitor comprising an oxidized conductive oxide electrode, an oxidized first layer of a high dielectric constant oxide dielectric material selected from the group consisting of Ta 2 O 5  and Ba x Sr (1−x) TiO 3  adjacent said oxidized conductive oxide electrode, a second layer of said high dielectric constant oxide dielectric material adjacent said first layer of said high dielectric constant oxide dielectric material, and an upper layer electrode adjacent said second layer of said high dielectric constant oxide dielectric material, and wherein said oxidized conductive oxide electrode and said oxidized first layer of said high dielectric constant oxide dielectric material are oxidized prior to the deposition of said second layer of said high dielectric constant oxide dielectric material.  
     
     
         12 . A capacitor as claimed in  claim 11  wherein said oxidized conductive oxide electrode is selected from the group consisting of RuO x  and IrO x .  
     
     
         13 . A capacitor as claimed in  claim 11  wherein said upper layer electrode is selected from the group consisting of RuO x  and IrO x .  
     
     
         14 . A capacitor as claimed in  claim 11  further comprising a gas permeable electrode adjacent to said upper layer electrode.  
     
     
         15 . A capacitor as claimed in  claim 14  wherein said gas permeable electrode comprises platinum.  
     
     
         16 . A capacitor as claimed in  claim 11  wherein said first layer of said high dielectric constant oxide dielectric material is between about 20 and about 50 Å thick.  
     
     
         17 . A capacitor comprising an oxidized conductive oxide electrode selected from the group consisting of RuO x  and IrO x , an oxidized first layer of a high dielectric constant oxide dielectric material selected from the group consisting of Ta 2 O 5  and Ba x Sr (1−x) TiO 3  adjacent to said oxidized conductive oxide layer; a second layer of high dielectric constant oxide dielectric material adjacent to said first layer of said high dielectric constant oxide dielectric material, and an upper layer electrode selected from the group consisting of RuO x  and IrO x  adjacent to said second layer of said high dielectric constant oxide dielectric material, and wherein said oxidized conductive oxide electrode and said oxidized first layer of said high dielectric constant oxide dielectric material are oxidized prior to the deposition of said second layer of said high dielectric constant oxide dielectric material.  
     
     
         18 . A capacitor as claimed in  claim 17  further comprising a gas permeable electrode adjacent said upper layer electrode.  
     
     
         19 . A capacitor as claimed in  claim 18  wherein said gas permeable electrode comprises platinum.  
     
     
         20 . A capacitor as claimed in  claim 17  wherein said first layer of said high dielectric constant oxide dielectric material is between about 20 and about 50 Å thick.