Nonvolatile memory device

摘要

A nonvolatile memory device is provided in which cell uniformity is significantly improved. The device includes a plurality of burial N+ diffusion layers extending over the surface of a semiconductor substrate. The plurality of burial N+ diffusion layers are the source/drains of cell transistors and the sub bit-lines of the memory cell array. The device additionally includes a plurality of word lines formed over the semiconductor substrate with gate dielectrics interposed therebetween. The plurality of word lines extend perpendicularly to the burial N+ diffusion layers. A plurality of select lines extend parallel to the word lines and selectively transfer external electrical signals via main bit-lines to the sub bit-lines. The main bit-lines extend parallel to said sub bit-lines. Finally, dummy lines extend parallel to the word lines in the spaces between the select lines and the adjacent word lines.