| 摘要 |
PURPOSE:To highly integrate a semiconductor storage device by forming a cell plate at the periphery of a columnar silicon projection, and forming a gate in a ring state at the top of the projection to form a switching transistor, thereby reducing the occupying area of the cell. CONSTITUTION:A first polycrystalline Si 5 is buried between columnar projections on a substrate to operate as the function of a cell plate. An extension portion is formed from an insulating layer 7 at the top of its capacitor, a gate electrode is formed of second polycrystalline Si 6 on the sidewall, and a switching transistor is formed together with source/drain region 11. The region 11 operates as a source when information is written and as a drain when information is read out. When a signal is applied to a word line 6 to turn the transistor ON, charge is stored in or discharged from the capacitor around the projection through the channel directly under the gate oxide film in response to the state of the bit line BL 12. Since adjacent capacitors are electrically separated by the channel stopper at the bottom of a groove, the capacitors are not affected by the influence of a punchthrough. |
