| 摘要 |
PURPOSE:To improve breakdown strength and leakage characteristic without lowering permittivity by making the insulating film of capacity for the insulating film of a three-layer structure in which a thin SiO2 film and a Si3N4 film are provided between a multicrystalline silicon electrode of a lower layer and a Ta2O5 film without mixing SiO2 from a multicrystalline silicon electrode side to a Ta2O5 film. CONSTITUTION:A thin SiO2 13 is formed on a first multicrystalline silicon electrode 12 which is a first electrode in a MIS capacitor of structure in which an insulating film an upper electrode are provided on a multicrystalline silicon layer formed in a memory cell of a dynamic RAM. After a thin Si3N4 film 14 is formed thereon and further a Ta2O5 15 is formed thereon, a second multicrystalline silicon electrode 16 which is a second electrode is formed. When the capacity insulating film of the three-layer structure is used, breakdown strength and leakage characteristic can be improved by the use of the lower Si3N4 and the SiO2 film 13 without lowering high permittivity of Ta2O5 because SiO2 is not mixed in the Ta2O5 film 15 by the action of the thin SiO3O4 film 14. |
