Conformal CVD-ruthenium process for MIM capacitor in giga-bit DRAMs

To realize the gigabit-scale DRAM capacitor, it is necessary to develop new electrode materials instead of poly-Si and TiN. Among them, Ruthenium has been the most promising electrode material in advance of Pt or Ir because it can be easily etched by oxygen plasma and shows good electrical properties as a capacitor electrode. But, a CVD-Ru film with good conformality and smooth morphology actually applicable to gigabit-scale DRAM generations has not been known up to now. In this work, we present the development of novel CVD process for application in real device with 3-dimensional structure and the electrical properties of capacitor using CVD-Ru electrode.