Study On Modeling Method Of Total Dose Irradiation Effect Of CMOS Inverter

With the development of space technology and nuclear technology,radiation has caused serious damage to electronic devices.The radiation environment damages the performance and functionality of the electronic device,thereby triggering the failure of the integrated circuit and causing huge losses.The total dose irradiation effect leads to the drift of the threshold voltage of Complementary Metal Oxide Semiconductor(CMOS)devices,causing the device to malfunction.Due to the high cost and time-consuming of irradiation experiments,it is now popular to use computer software to simulate the behavior of electronic devices in the irradiation environment,which provides help for the design,simulation and reliability analysis of integrated circuits.In view of the above situation,two work has been carried out in this paper.(1)Extraction of sensitivity parameters for Total Dose Irradiation(TID)of CMOS Inverter.Consists of a pair of complementary enhanced Metal Oxide Semiconductor(MOS)field effect transistors,the CMOS inverter is the basic module in the digital circuit design.As a sensitivity parameter of the total dose irradiation effect and a characteristic parameter in the total dose irradiation effect modeling,the threshold voltage of MOS has attracted wide attention.The common threshold voltage extraction method is based on the transfer characteristic curve of the MOS device,that is,the relationship between the drain current and the gate voltage of the MOS device.However,the four ports of the CMOS inverter cannot measure the current,so the common threshold voltage extraction method cannot be used.To solves this problem,this paper proposes a threshold voltage extraction method of CMOS inverter based on voltage transfer characteristic(VTC)curve.In order to verify the accuracy of the threshold voltage extraction method of CMOS inverter based on VTC curve proposed in this paper,two experimental samples,FDS8960 C and NC7SZU04,were selected for experiments.This paper compares experimentally extracted values with typical values.In order to prove that the extraction method of this paper can provide help for subsequent modeling,two experimental samples were simulated in the System Vision simulation software,and the simulation data was compared to the experimental data of the device.The contrast is good.This paper proves the availability of the extraction method.The extraction method in this paper can lay the foundation for the subsequent simulation modeling.(2)Modeling the Total Dose Irradiation effect of CMOS Inverter.The widely used total dose irradiation effect simplified model ignores the radiation dose rate effect.The simplified model considers that the threshold voltage shift caused by irradiation is a linear relationship with the total irradiation dose,which reduce its accuracy.In fact,different radiation dose rates lead to different electric field distributions in the gate oxide layer,and eventually lead to the different threshold voltage drift.In order to improve the accuracy of modeling,this paper proposes an improved model of total dose irradiation effect of CMOS inverter considering the effect of irradiation dose rate.In order to verify the accuracy of the improved model of the total dose irradiation effect of the CMOS inverter proposed in this paper,the total dose irradiation experiment was performed on the FDS8960 C.The threshold voltage of the device was reduced in the irradiation experiment.The conclusion is that the error of the improved model is smaller and the model accuracy is higher.In order to prove that the improved model can be applied to the computer simulation of total dose irradiation effect,the total dose irradiation effect of FDS8960 C was simulated in System Vision,which proved that the model has strong usability.This paper proposes a threshold voltage extraction method of CMOS inverter based on VTC curve,which solves the problem that common methods based on transfer characteristic curve cannot be used in CMOS inverter.This paper proposes an improved model of the total dose irradiation effect of the CMOS inverter to slove the problem of the low accuracy of the simplified model.The improved model improve the accuracy of the total dose effect computer simulation of CMOS inverters,and can provide a certain reference for the antiradiation design and reinforcement of integrated circuits.