MEMORY DEVICE FOR SEMICONDUCTOR

PURPOSE:To design stabilization of manufacturing by impressing on a one side main electrode of memory transistors, a gate of no selection line and a substrate successively. CONSTITUTION:Voltage is impressed on memory transistor sources for all bits by the first high voltage impressing means, and voltage is applied only on a gate for a memory transistor of no selection line by the second high voltage applying step. Thereafter, voltage is impressed on a memory substrate by the third high voltage impressing means. In regard to memory transistors M11, M12, the threshold VTH moves in the depressional direction by potential difference between the gate and the substrate to eliminate contents of memory. On the other hand, the threshold is not changed, in regard to no selection memory transistors M21, M22, because of no potential difference between the gate and the substrate, and contents of the memory are not eliminated. Thereafter, the memory substrate must be back to Vss, gate to Vss, and finally the source to Vss. Thus, impressing high voltage successively, stabilized production of non-volatile memory becomes possible.