| 摘要 |
PURPOSE:To ensure a capacity required for a memory operation, by constructing the capacity part of a memory cell by using two columnar and hollow conductive members. CONSTITUTION:A memory cell has an MOS transistor and a capacity part. The capacity part is formed of a storage electrode comprising a first conductive member 8 connected to an N-type source-drain region 5-1, a second conductive member 9b shaped in a ring and connected on the member 8 and a third conductive member 10b disposed concentrically with the member 9b, and of a cell plate 12 and a capacity insulation film 11. As a component of the storage electrode, the inner and outer walls of the two columnar and hollow conductive members are used as the capacity part respectively. According to this constitution, a large capacity can be ensured without increasing the height of the storage electrode and with a stepped part of the surface of an element held small. |
