| abstract |
A dynamic random access memory device ( 100 ) includes storage capacitors using a high dielectric constant material, such as, BaSrTiO 3 , SrBi 2 Ta 2 O 9 and PbZrTiO 3 , 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. An isolation dielectric ( 132 ) can be deposited over the conductor at a high temperature without causing oxygen or metallic diffusion through the first and second diffusion barrier layers. |