2-DIMENSIONAL SIMULATION OF TOTAL-DOSE EFFECTS ON NMOSFET WITH LATERAL PARASITIC TRANSISTOR

The trapped charge density in the LOGOS bird's beak resulting from irr adiating a conventional NMOSFET has been analysed using a 2D finite el ement simulation. This paper shows a maximum of trapped charge density in the bird's beak region. The resulting voltage shift of the lateral parasitic transistor in the bird's beak region induces a high leakage current, and prevents any normal circuit operation. The silicon dopin g level, the supply voltage and the bird's beak shape are key paramete rs for device hardening of rad-tolerant technologies.