| 摘要 |
PURPOSE:To improve the TDB of a capacitor by constructing polycrystalline silicon used as an electrode of a cell contact part of a DRUM as a double layered structure by growing the same two times, doping arsenic into a lower layer side and phosphorus into an upper layer side, and forming an oxide film on the upper portion of the electrode located at an interface between both layers. CONSTITUTION:A p type semiconductor substrate 1 is provided, at a proper location of which a source 2 and a drain 3 are formed. A first semiconductor polycrystalline layer 8 comprising polycrystalline silicon is provided at a proper location on an electrode opening located on the upper portion of cell contacts 2a, 3a, and on an insulating film 7, into which layer 8 arsenic is diffused as an impurity. Oxygen ion is doped into the upper portion of the cell contacts 2a, 3a on the surface of the first semiconductor polycrystalline layer 8 to form a silicon oxide film 10. Further, a second semiconductor polycrystalline layer 11 comprising polycrystalline silicon is provided on the first semiconductor polycrystalline layer 8 containing the silicon oxide film 10, into which layer 11 phosphorus is diffused as an impurity. |
