Buffer layers to enhance the C-axis growth of Bi4Ti3O12 thin film on high temperature iridium-composite electrode

摘要

A method of fabricating a ferroelectric thin film on an iridium-composite electrode in an integrated circuit device includes preparing a substrate; depositing an iridium-composite bottom electrode on the substrate; annealing the bottom electrode in a first annealing step; depositing a buffer layer on the bottom electrode, including depositing a layer of material taken from the group of materials consisting of HfO₂, ZrO₂, TiO₂, LaO_x, La-Al-O, Ti-Al-O, Hf-Al-O, Zr-Al-O, Hf-Zr-O, Zr-Ti-O, Hf-Ti-O, La-Zr-O, La-Hf-O, and La-Ti-O; annealing the buffer layer in a second annealing step; depositing a layer of Bi₄Ti₃O₁₂, to a thickness of between about 20 nm to 500 nm, on the buffer layer; annealing the ferroelectric layer in a third annealing step; and completing the integrated circuit device.