Adhesion of Ferroelectric Material to Underlying Conductive Capacitor Plate

摘要

Deposition of lead-zirconium-titanate (PZT) ferroelectric material over iridium metal, in the formation of a ferroelectric capacitor in an integrated circuit. The capacitor is formed by the deposition of a lower conductive plate layer having iridium metal as a top layer. The surface of the iridium metal is thermally oxidized, prior to or during the deposition of the PZT material. The resulting iridium oxide at the surface of the iridium metal is very thin, on the order of a few nanometers, which allows the deposited PZT to nucleate according to the crystalline structure of the iridium metal rather than that of iridium oxide. The iridium oxide is also of intermediate stoichiometry (IrO2-x), and reacts with the PZT material being deposited.

主权项

1. A method of fabricating an integrated circuit including a ferroelectric capacitor, comprising the steps of:
depositing a first conductive film near a semiconducting surface of a body, the first conductive film comprising a portion of iridium metal at the surface of the first conductive film; oxidizing the surface of the iridium metal portion; depositing ferroelectric material comprising lead-zirconium-titanate over the first conductive film by metalorganic chemical vapor deposition comprising the steps of: depositing a second conductive film overlying the ferroelectric material; and removing portions of the first and second conductive films, and the ferroelectric material, at selected locations, to define the ferroelectric capacitor.