Charge and potential distribution in dielectric layers of MOS structures under ionization

Parameter changes of metal—oxide—semiconductor (MOS) structures under ionizing radiation are caused by the buildup of a positive charge in the oxide which value and topology depend in a complex way on the applied voltage. A proposed simple model and calculation method for the potential distribution in MOS-structure, with arbitrary value and polarity of the applied voltage and based on the solution of the Poisson and kinetic equations system with account of boundary conditions changing with the applied voltage, allow to determine the topology and value of the buildup charge and the resulting shift of the MOS-characteristics in good agreement with experiments.