Semiconductor memory device

Abstract

In a semiconductor memory device in which each memory cell is constituted by one transistor, in a memory cell pattern, two adjacent bits form one diffusion pattern, two adjacent transistors share a source region, and two drain regions are separated from each other. A plurality of arrays in each of which at least a column of the diffusion patterns is disposed include bit lines, and the bit lines of the first array are independent of the bit lines of the second array. In an interface between the arrays, ends at one side of the bit lines of each of the arrays are located on an associated one of two drain regions which are separated from each other with the source region which is shared on one diffusion pattern sandwiched therebetween. This configuration can provide a sufficient bit-line separation width, and reduce the area.