| 摘要 |
PURPOSE:To miniaturize a memory cell while securing the accumulated charge by burying a conductive film, which constitutes part of fin structure of accumulating electrode, within the space made by removing one part on one hand of two kinds of insulating films. CONSTITUTION:A silicon nitride film 9a, a silicon oxide film 10a, a silicon nitride film 9b, a silicon oxide film 10b, and a silicon nitride film 9c different in etching speed are stacked in order on a MISFET for selection of a memory cell. A contact hole 12 is made in a semiconductor region 7 by dry-etching the stacked insulating film. One part each of the silicon oxide films 10a and 10b is removed from the exposed section of the sidewall of the contact hole 12 by the difference of etching speed so as to form space 13. A polycrystalline silicon film 14 to serve as an accumulating electrode is stacked, and further it is filled up in the space 13, too. Hereby, the short between the capacitive elements of adjacent memory cells caused by the remainings behind etching of the polycrystalline silicon film 14 vanishes. |
