| 摘要 |
PURPOSE: The method is for increasing capacitance and also preventing the increase of leakage current by lowering the thickness of a dielectric film and for reducing the amount of capacitance change. CONSTITUTION: The method is characterized by forming a capacitor of MIM structure where a bottom electrode and a top electrode is made of metal, by forming the bottom electrode and the top electrode of the capacitor having a Ta2O5 dielectric film(19) with a TiN film(16, 20). The method can reduce the leakage current because the difference of work function between the Ta2O5 film and the TiN film is larger than the difference of work function between the Ta2O5 film and a polysilicon film, and can reduce the amount of capacitance change by using a metallic film as the bottom electrode and the top electrode, and can increase capacitance by forming the dielectric film with a thinner effective oxide film.
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