| 摘要 |
A semiconductor device includes (a) a first conductivity type semiconductor substrate having a plurality of trenches formed therein, the trenches defining a plurality of device regions between adjacent trenches, (b) a second conductivity type diffusion layer formed at least around an outer surface of each of the device regions, (c) an insulating film formed on the inner surface of each of the trenches to cover a part of the second conductivity type diffusion layer therewith, (d) a plate electrode formed within each of the trenches, (e) a gate electrode formed above the second conductivity type diffusion layer and (f) a gate insulating film interposed between the gate electrode and the second conductivity type diffusion layer to isolate the gate electrode from the second conductivity type diffusion layer. This semiconductor device eliminates the need for the second conductivity type diffusion layer to serve as a capacitor electrode in contact with a switching transistor. Thus, a vertical type transistor in which the control of impurities profile and gate oxide layer thickness profile is quite difficult, is not used, yet a memory cell as small as the vertical type transistor can be obtained.
|
