Abstract: Reduced diffusion of excess mobile specie from a metal oxide ceramic is achieved by tailoring the composition an/or deposition parameters. A barrier layer which reacts with the excess mobile specie is provided below the metal oxide ceramic to prevent or reduce the diffusion of the excess mobile specie through the bottom electrode and into the substrate.

Abstract: A dynamic random access memory device (100) includes storage capacitors using a high dielectric constant material, such as, BaSrTiO3, SrBi2Ta2O9 and PbZrTiO3, for the capacitors' insulator. The device includes a conductive plug (106) formed over and connecting with a semiconductor substrate (102). A buffer layer (107) of titanium silicide lays over the plug, and this layer serves to trap “dangling” bonds and to passivate the underlying surface. A first diffusion barrier layer (108), e.g., titanium aluminum nitride, covers the titanium silicide. A capacitor first electrode (110) lays over the diffusion barrier layer. The high dielectric constant material (112) is laid over the capacitor first electrode. A capacitor second electrode (116) is laid over the high dielectric constant material. A second diffusion barrier layer (120) is deposited on the capacitor second electrode. A conductor, such as aluminum (130), is laid over the second diffusion barrier layer.