Methods of preventing reduction of IrOx during PZT formation by metalorganic chemical vapor deposition or other processing

A method of forming an FeRAM capacitor, comprising:

• forming an iridium oxide layer as at least a portion of a bottom electrode layer over a substrate;
• forming a PZT ferroelectric dielectric layer over the iridium oxide layer;
• and
• using iridium to reduce a diffusion of oxygen out of the iridium oxide layer during the formation of the PZT ferroelectric dielectric layer.

A method of forming an FeRAM capacitor, comprising:

• forming a first iridium layer over a substrate;
• forming a first iridium oxide layer over the first iridium layer;
• forming a second iridium layer over the iridium oxide layer;
• forming a PZT ferroelectric dielectric layer over the second iridium layer, wherein during a first phase of the PZT layer formation, oxygen diffusing out of the first iridium oxide layer is trapped by the second iridium layer, and wherein the second iridium layer is thereby transformed into an oxygen doped iridium layer, and wherein during a second phase of the PZT layer formation, a reducing ambient associated with the PZT layer formation causes the oxygen doped iridium layer to transform to a second iridium oxide layer, and wherein the first and second iridium oxide layer together form a bottom electrode iridium oxide layer;
• forming a third iridium oxide layer over the PZT layer;
• and
• forming a third iridium layer over the third iridium oxide layer, wherein the third iridium oxide layer and the third iridium layer together form a top electrode of the FeRAM capacitor.