| 摘要 |
PURPOSE:To obtain a non-volatile memory storage having an excellent efficiency of erase and holding characteristic of memory by continuously reducing charge capture level density in an Si3N4 to the interface of a metal-Si3N4 from the interface of Si3N4-SiO2. CONSTITUTION:When charge density in an Si3N4 3 is uniform in an MNOS type FET, the center of the distribution of charge density captured exists at the Si3N4 side from the interface of SiO2 2 and Si3N4 3, erasing voltage applied to a gate 4 and gate width must be increased more than when the center of the distribution exists in the interface, and the efficiency of erase is inferior. Charges flow out to the gate 4 as far as the distribution of charges is not uniform under a condition that charges are held in Si3N4, and the holding property of memory is improved with the decrease of charge capture level density in Si3N4, but the cente of the distribution of charge density deeply intrudes into Si3N4, and the efficiency of erase degrades. According to this constitution, since a dielectric-constant discontinuous surface is not generated in Si3N4 and an electric field does not concentrate, dielectric breakdown is not generated at pulse voltage for injecting and discharging charges, and the non-volatile memory storage having excellent characteristics is obtained. |
