Semiconductor device including capacitor with lower electrode including iridium and iridium oxide layers

A semiconductor memory device, comprising:

• a capacitor formed on a substrate and including a lower electrode, a dielectric film and an upper electrode;
• a selection transistor formed at the substrate;
• an electrically conductive plug for providing electrical connection between the selection transistor and the capacitor;
• and
• a diffusion barrier film provided between the electrically conductive plug and the lower electrode of the capacitor;
• wherein the diffusion barrier film is a TaxSi1−xNy film or a HfxSi1−xNy film (where 0.2<x<1 and 0<y<1),
• the lower electrode includes an Ir film and an IrO2 film which are sequentially formed;
• wherein the lower electrode includes the Ir film, a thin film, and said IrO2 film which are sequentially formed, and a formation temperature of the thin film is less than a formation temperature of said IrO2 film.