Nonvolatile semiconductor memory device and manufacturing method thereof

Abstract

A nonvolatile semiconductor memory device includes a semiconductor substrate, plural semiconductor columns arranged in a matrix form on the substrate, plural first conductive areas zonally formed in a column direction on the substrate between the semiconductor columns and functioning as word lines, plural second conductive areas formed at tops of the semiconductor columns, respectively, plural bit lines connecting the second conductive areas in a row direction, plural channel areas respectively formed in the semiconductor columns between the first and second conductive areas and contacting the first and second conductive areas, plural third conductive areas continuously formed via first insulating films above the substrate and opposite to the channel areas in the column direction between the semiconductor columns and functioning as control gates, and plural charge accumulation areas respectively formed via second insulating films at upper portions of the channel areas at a position higher than the third conductive areas.