Non-volatile semiconductor memory device and fabrication method thereof

摘要

A non-volatile semiconductor memory device is provided with a circuit that protects a tunnel oxide film from the charging phenomenon. This circuit comprises a first junction diode including an N+-type diffusion layer and a P-type well, and a second junction diode including a P-type well and an N-type well. When a voltage applied to the control gate is greater than all of a write voltage, a read voltage, and an erasure voltage that would be applied to the control gate, a current is guided through that circuit.