A dielectric region, such as a ferroelectric dielectric region of an
integrated circuit capacitor, is protected by a multi-layer insulation
structure including a first relatively thin insulation layer, e.g., an
aluminum oxide or other metal oxide layer, and a second, thicker
insulating layer, e.g., a second aluminum oxide or other metal oxide
layer. Before formation of the second insulation layer, the first
insulation layer and the dielectric preferably annealed, which can
increase a remnant polarization of the dielectric region. The first
insulation layer can serve as a hydrogen diffusion barrier during
formation of the second insulation layer and other overlying structures.
In this manner, degradation of the dielectric can be reduced. Devices and
fabrication methods are discussed.
