| 摘要 |
PURPOSE:To provide a simple manufacturing method of a semiconductor memory capable of making the high integration compatible with the increase in the capacitor capacitance. CONSTITUTION:Undercut parts 67 are formed on the lower boundary parts of accumulated electrodes 59. At this time, dielectric films 60 and opposite electrodes 61 are formed inside the undercut parts 67. Therefore, the electrode areas can be increased by the areas of the undercut parts 67 without increasing the aspect ratio of the accumulated electrodes 59. The undercut parts 67 are isotropically etched away after the formation of the accumulated electrodes 59 so that the lower boundary parts of the accumulated electrodes 59 may be actively side-etched away. At this time, the etching requirement should be the higher selection ratio for insulating layers 58 (i.e., having higher selection ratio for silicon resistant oxide film) so that the needless etching step of the insulating layers 58 during the forming step of the undercut parts 67 may be avoided. |
