Prediction Method for Total Dose Effects on Complementary Metal Oxide Semiconductor Integrated Circuits Using Impulse Response Model for Threshold Voltage Shift

A method is described to predict radiation hardness of general purpose CMOS logic ICs.The method uses an impulse response model for radiation-induced threshold voltage shift of an "elemental IC" selected from an IC family. The total dose degradation on ICs can be predicted at any dose rate by simulations using the impulse response model of the threshold voltage shift and their circuit structure data. This method was applied to the prediction of radiation degradation of CMOS logic ICs of HD74HC series, in which an inverter HD74HC04 was selected as the elemental IC. Four inverter samples were irradiated up to 100 Gy (Si) and then annealed to examine the impulse response of the threshold voltage shift of their n- and P-channel MOSFETs. Results predicted by this method represented the static characteristic degradation of the HD74HC04 irradiated up to a large total dose 1 kGy (Si) at two different dose rates 8 and 500 Gy (Si) /h.