Composite iridium-metal-oxygen barrier structure with refractory metal companion barrier and method for same

Abstract

An Ir—M—O composite film has been provided that is useful in forming an electrode of a ferroelectric capacitor, where M includes a variety of refractory metals. The Ir combination film is resistant to high temperature annealing in oxygen environments. When used with an underlying barrier layer made from the same variety of M transition metals, the resulting conductive barrier also suppresses to diffusion of Ir into any underlying Si substrates. As a result, Ir silicide products are not formed, which degrade the electrode interface characteristics. That is, the Ir combination film remains conductive, not peeling or forming hillocks, during high temperature annealing processes, even in oxygen. The Ir—M—O conductive electrode/barrier structures are useful in nonvolatile FeRAM devices, DRAMs, capacitors, pyroelectric infrared sensors, optical displays, optical switches, piezoelectric transducers, and surface acoustic wave devices. A method for forming an Ir—M—O composite film barrier layer and an Ir—M—O composite film ferroelectric electrode are also provided.

Dependencies are inferred from the claim text.