Semiconductor memory device capable of realizing a chip with high operation reliability and high yield

Abstract

A semiconductor memory device capable of preventing occurrence of a defect caused by a lowering in the etching precision in an end area of the memory cell array and realizing an inexpensive chip having high operation reliability and high manufacturing yield is provided. A first block is constructed by first memory cell units each having a plurality of memory cells connected, a second block is constructed by second memory cell units each having a plurality of memory cells connected, and the memory cell array is constructed by arranging the first blocks on both end portions thereof and arranging the second blocks on other portions thereof. The structure of the first memory cell unit on the end side of the memory cell array is different from that of the second memory cell unit. Wirings for connecting the selection gate lines of the memory cell array to corresponding transistors in a row decoder are formed of wiring layers formed above wirings for connecting control gate lines of the memory cell array to the transistors in the row decoder. By use of the semiconductor memory device, occurrence of a defect caused by a lowering in the etching precision in an end area of the memory cell array can be prevented, and the manufacturing yield can be made high and the operation reliability can be made high without substantially increasing the chip size.