| 摘要 |
PURPOSE:To reduce an occupying area largely by forming a floating gate electrode to the lower layer of a recessed section and shaping a nonvolatile semiconductor memory cell and a switching transistor at the same planar position. CONSTITUTION:A floating gate electrode 7 buried into the lower layer of a recessed section 5 through a first insulating film 6 and a second insulating film 8 onto the electrode 7 are formed. The electrode 7 is shaped in such a manner that polycrystalline Si is laminated so as to bury the recessed section 5, etched up to approximately the intermediate section of the recessed section 5 and arranged to the lower layer of the recessed section 5 at that time. Lastly, a control electrode 9 crossing the insulating film from a source 3 and being formed up to a drain 4 is shaped. The electrode 9 is formed between the source 3 and the drain 4 through the insulating film 8, and polycrystalline Si is buried and etched. A nonvolatile semiconductor memory cell and a switching transistor are shaped at the same planar position. |
