US Patent 7978561 Semiconductor memory devices having vertically-stacked transistors therein

Provided is a semiconductor device having transistors of stacked structure. The semiconductor memory device having transistors includes a memory cell array block which includes a plurality of word lines and a plurality of memory cells which each includes at least one first transistor connected between the plurality of word lines, and a word line decoder which includes a plurality of drivers which drive the plurality of word lines, respectively, wherein a plurality of word lines are disposed on a first layer, and a plurality of drivers are disposed on at least two second layers.