| 摘要 |
PURPOSE:To enable the charge to be inputted in a gate insulating film by a method wherein the field effect from a gate electrode to a substrate surface is abruptly changed in the changing part of gate insulating film of a MISFET as a memory cell. CONSTITUTION:n<+> type semiconductor regions 5 are formed by implanting n<+> type impurity e.g. phosphorus or arsenic using a gate electrode 10 as a mask to be used as a source region in writing-in data and as a drain region in reading-out the same. A channel region 1A covered with thick insulating film 9 below the gate electrode 10 is hardly affected by the electric field effect from the electrode 10. Resultantly, when the electrode 10 is impressed with high potential around 9V in writing-in data, a barrier to potential is formed against the region 1A while a channel region 1B is below the part coating the exposed silicon oxide film 6 of electrode 10 easily forming an inversion layer at low potential around 7V. Through these procedures, electrons can be injected by partially changing potential in the channel regions to lower the writing potential.
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