Ferroelectric capacitors for integrated circuit memory devices and methods of manufacturing same

Abstract

Methods of forming integrated circuit capacitors having dielectric layers therein that comprise ferroelectric materials, include the use of protective layers to block the infiltration of hydrogen into the ferroelectric material. By blocking the infiltration of hydrogen, the hysteresis characteristics of the ferroelectric materials can be preserved. A preferred integrated circuit capacitor comprises a semiconductor substrate and a lower capacitor electrode on the semiconductor substrate. A capacitor dielectric layer that comprises a ferroelectric material, is provided on the lower capacitor electrode. An upper capacitor electrode is also provided on the capacitor dielectric layer. In order to inhibit degradation of the ferroelectric characteristics of the capacitor dielectric layer, a protective layer is utilized to cover the capacitor dielectric layer. In particular, the protective layer is formed to encapsulate the upper capacitor electrode and the capacitor dielectric layer. The protective layer preferably includes a material that is substantially free of hydrogen and has a chemical and/or physical structure that blocks transfer (e.g., diffusion) of hydrogen therethrough. The protective layer may also have a thickness of greater than about 50 Å, in order to further inhibit transfer of hydrogen from outside the protective layer to the underlying capacitor dielectric layer. The protective layer may comprise a metal oxide selected from the group consisting of Al2O3, TiO2, SiO2, ZrO2 and CeO2.

Dependencies are inferred from the claim text.