Analysis of techniques to separate the ionizing-radiation-induced charge components in irradiated MOSFETs

Abstract

Power Metal Oxide Semiconductor Field-Effect Transistors (MOSFETs) are widely used in power supplies for spaceborne electronic systems. Spacecraft are routinely subjected to ionizing radiation. Ionizing-radiation-induced charges alter the operation of the MOSFET. The mid-gap technique allows separation of the parameter shifts into components due to oxide trapped charge and interface trapped charge. However, non-linearity in the subthreshold curve results in an approximately 20% underestimation of the interface component of the threshold shift. A new characterization technique is presented based on the relation between gate charge and gate-source voltage. The results obtained using the gate-charge method agree with theoretical calculations.