| 摘要 |
PURPOSE:To make possible the accumulation of sufficient signal electric charge to the reduction of element size by burying a transistor through an insulator in a trench which is bored to penetrate a word wire (layer of gate electrode) in a semiconductor board and forming an n-type diffusion layer on the face of the trench to be a cell plate electrode. CONSTITUTION:A transistor part makes a trench of a p-type semiconductor layer 61 buried in the trench 64 as a channel, an n<+>-type semiconductor layer 62 on the upper part of the trench 64 which is used as a bit wire commonly as a source electrode, an n<+>-type semiconductor layer 60 buried on the lower part of the trench 64 which is used as a drain electrode, a gate electrode 54 (combined use of word wire) surrounding the trench 64 and a gate insulating film 59 of its surface. In a capacity part, a MOS capacitor comprises an electric charge accumlating part of the n<+>-type semiconductor layer 60 formed in the trench 64 to sandwich a dielectric body 58 formed on the surface of the trench 64 of a semiconductor substrate 51 and an n<+>-type diffusion layer 57 at the side of the semiconductor substrate 51 which becomes a cell plate electrode. However, the numeral 63 designates an intermediate insulating film. |
