Patent ID: 7105885

Claim:
A semiconductor device which consists essentially of: a bottom electrode of a capacitor connecting to a substrate through a tungsten contact plug; a contact plug; a first diffusion barrier layer formed as a single layer connected to the contact plug, comprising CrXMe1-XN containing Cr, a metal (Me) and N, wherein the metal (Me) is at least one member selected from Ti and Ta, and, wherein the first diffusion barrier layer prevents mutual diffusion between the first diffusion barrier layer and the tungsten contact plug; a second diffusion barrier layer formed as a single layer connected to the first diffusion barrier layer, comprising a material selected from the group consisting of IrO2, RuO2 and SrRuO3 disposed on the first diffusion barrier layer for preventing the Cr in the first diffusion barrier layer from diffusing into the bottom electrode, wherein the second diffusion barrier layer also prevents a constitutional material of the first diffusion barrier layer from diffusing into the bottom electrode; a bottom electrode formed on the second diffusion barrier layer; a dielectric layer disposed on the bottom electrode; and a top electrode disposed on the dielectric layer.