Gate-charge measurements for irradiated n-channel DMOS power transistors

Gate-charge measurements provide information on power-MOSFET capacitances, drive requirements, and power dissipation. A gate-charge curve is a plot of gate-top-source voltage vs. charge supplied to the gate by a current source, and it consists of three distinct regions. Ionizing radiation affects primarily the second, or plateau, region. The change in the plateau voltage is related to the radiation-induced threshold-voltage shift, while the length of the plateau increases with the density of radiation-induced interface traps. Radiation-induced changes in the gate-charge curve provide useful information to circuit designers, as well as information on charge densities in the device