Semiconductor device and a integrated circuit card

Abstract

It is possible to suppress or prevent so-called write disturbance phenomenon from occurring in write-disabled non-selected memory cells in a semiconductor device, in any selected one of which data can be written electrically by means of the so-called tunneling phenomenon. In a flash memory that can disable writing of data by suppressing injection of electrons in the accumulation layer of each non-selected memory cell in which data is to be written with a writing disable voltage applied to the drain thereof before a write voltage is applied to the control gate electrode of each selected memory cell, the relationship among a writing disable voltage Vwd, a read voltage Vr applied to the drain of a selected memory cell from which data is to be read, and a punch-through withstand voltage BVds between the source and the drain of each selected memory cell is set to satisfy Vr<BVds<Vwd.