NON-VOLATILE SEMICONDUCTOR STORAGE DEVICE

摘要

PURPOSE:To control the threshold voltage of a non-volatile storage element to be erased by monitoring the current flowing to this storage element to control a switch CONSTITUTION:A switch MOSFET Q17 which gives an erase voltage to a source line to which a non-volatile storage element Q1, which is provided with a control gate and a floating gate and has a stacked gate structure, is connected is so controlled that this switch is turned off at the time of detecting the current flowing to the non-volatile storage element Q1 to be erased. Thus, the electric characteristic of the non-volatile storage element is used and the change of its threshold voltage is monitored to prevent the excessive erase operation of the non-volatile storage element.