SEMICONDUCTOR MEMORY DEVICE

摘要

PURPOSE:To realize the super-integration of a RAM by a method wherein, in preparing the dynamic RAM with three MOS transistors, a write-address transistor is stacked on a read-address transistor via interlayer insulation film. CONSTITUTION:Element-isolating insulation films 5 and 6 are formed on a semiconductor substrate 1 of the first conductivity type, and the second conductivity type regions 2, 3, and 4 are diffusion-formed in the surface layer part of the substrate 1. Next, positioned between the regions 2 and 3, a gate electrode 9 is provided via gate insulation film 7; then, the interlayer insulation film is adhered over the entire surface, and this is split into films 15, 16, and 19 by boring apertures. Thereafter, the exposed surface of the film 16 on the electrode 9 is provided with the second conductivity type region 10 contacting the region 2 and with a gate electrode 12 having an interposed gate insulation film 8 by sandwiching the first conductivity type region 11, and a gate electrode 13 is mounted on the region 11 via gate insulation film 14. The first element mainly made of a gate electrode 13, the third element mainly made of the electrode 9, and the second element mainly made of the electrode 12 are constructed in such a manner.