Semiconductor memory device with mos transistors each having floating gate and control gate

Abstract

A semiconductor memory device includes memory cells, a memory cell array, word lines, a row decoder, first metal wiring layers, and metal wiring lines. The memory cell includes a first MOS transistor having a charge accumulation layer and a control gate. Each word line is formed by connecting commonly the control gates in a same row. The row decoder selects any one of the word lines. The first metal wiring layers are provided for the word lines in a one-to-one correspondence. The first metal wiring layers are electrically connected to the corresponding ones of the word lines and transmit a first row select signal for the row decoder to select one of the word lines. The metal wiring lines are formed at a plurality of levels. The first metal wiring layers are made of the metal wiring lines located at the level of the lowest layer.