Charge Distributions in MOS Capacitors for Larg Irradiation Doses

The distributions of electrons, holes, ionized traps, electric fields and electrostatic potentials were obtained by computer simulation for an MOS capacitor subjected to large radiation dose levels. The results were obtained for irradiation over a wide range of both positive and negative values of gate bias voltages. The simulation results implied that, above a certain critical radiation dose level, the resulting flat band shift after even a very small incremental dose should be independent of all previous gate bias history. This conclusion was verified by experimental measurements.