| 摘要 |
PURPOSE:To ensure fundamental action as the memory cell, and to obtain device structure enabled to have a large storage voltage by a method wherein an electrode material having the specified value of the difference between the Fermi level of the gate electrode and the intrinsic Fermi level of a substrate semiconductor is used. CONSTITUTION:When the P type semiconductor substrate 6 is used, the gate electrode 1 material having the large work function as compared with N<+> type poly-silicon, P<+> type poly-silicon for example, is used. The necessary implanting quantity of boron ions for formation of a P type channel doped layer 2 can be reduced than the case when an N<+> type poly-silicon gate is used, the shallow channel doped layer 2 can be formed, the potential barrier of a buried channel layer 3 for holes can be reduced sufficiently, and because holes stored by writing ''1'' can be swept out surely to the substrate 6, the difference between the number of holes existing in the channel doped layer 2 corresponding to the ''1'' condition and the ''0'' condition can be enlarged, the storage voltage can be enlarged according thereto, and the operational margin is enlarged. |
