| 摘要 |
PROBLEM TO BE SOLVED: To form the plate contact of a DRAM with COB(capacitor over bit line) structure stably and efficiently. SOLUTION: A cylindrical capacitor 15 is formed at a capacitor formation region I and at the same time two dummy patterns 15d that are electrically irresponsive are formed also at a plate contact formation region II. An etching stop layer 6d in formed is advance by a film that is common to a bit line 6 at the lower part of a space between the dummy patterns 15d. An interlayer insulation 16 is subjected to dry etching and at the same time each contact hole connected to a plate electrode 14, a diffusion layer 3, and a word line 4 is formed. The depth of a pair of plate electrode contact holes 21 is shallower than that of other holes but the contact holes 21 are formed to a proper depth since a plate electrode 14 with a slow etching speed is greatly exposed in the hole. Also, a contact area between the plate electrode 14 and a plate drawing electrode is increased. |
