Semiconductor memory device and production method therefor

摘要

A semiconductor memory device including: a semiconductor substrate; a plurality of memory cells arranged in a matrix having columns and rows on the semiconductor substrate and each including a source, a drain and a control gate; a plurality of insulative device isolation layers positioned in a surface portion of the substrate as extending in a column direction for isolating the memory cells arranged in each row of the matrix; a plurality of word lines positioned on the substrate as extending in a row direction and each constituted by the control gates of the memory cells of the each row which are connected in series; the source and the drain of each of the memory cells of the each row being positioned in the surface portion of the substrate on opposite sides of a corresponding one of the word lines between an adjacent pair of insulative device isolation layers; and a common source line positioned on the substrate between an adjacent pair of word lines with the intervention of side wall films positioned on side walls of the word lines as extending across the insulative device isolation layers and connecting the sources of the memory cells of the each row in series.