Modeling Total Dose Effect In CMOS Digital Integrated Circuits

With the rapid development of semiconductor technology,all kinds of analog and digital integrated circuits are widely used in aerospace,nuclear industry,particle physics and other fields.They are in the radiation environment of various electromagnetic and high energy particles.Affected by a variety of radiation effects,such as total dose radiation,single particle radiation and instantaneous effects,their working reliability and life have been severely challenged.Among them,the total dose radiation effect has received extensive attention.In recent years,with the development of computer simulation technology,the radiation effect simulation of electronic system provides strong support for system anti-radiation design and theoretical research,which not only shortens the research and development cycle but also reduces the development cost.At present,there are mainly two kinds of research on modeling total dose effect in digital integrated circuits: transistor-level model based on underlying physics and function-based behavior model.The transistor-level model has high simulation accuracy and a wide range of applications,but its computational overhead is large,and the scale of the simulation circuit is limited.The behavioral model does not involve the underlying physics,the model is simple,and the simulation efficiency is high,but it is too dependent on experimental data to make an accurate response to environmental changes.To solve the above problems,a behavioral-physical hybrid model for Complementary-Metal-Oxide-Semiconductor(CMOS)digital integrated-circuits(IC)is proposed in this thesis.the model has the advantages of wide application range and high simulation accuracy of physical model,and good versatility and fast simulation speed of behavioral model.It is suitable for board-level simulation and can well describe the effect of total dose effect on devices.This thesis is based on the creation process of CMOS digital IC behavior-physical hybrid model.The main research is summarized as follows:(1)A hybrid behavioral-physical modeling method for CMOS digital integrated circuits is proposed.The hybrid model consists of a functional area module describing the logic function of the device and a physical structure module of input and output ports.(2)the electrical characteristic measurement system of CMOS digital integrated circuit port is built.The premise of the physical modeling of the CMOS digital IC port is to obtain the V-I characteristic curves of the transistors that make up the port circuit.In this thesis,based on the analysis of the principle of port characteristic measurement,a test system is built based on NI PXIe system and Lab VIEW development environment.(3)physical model construction of CMOS digital integrated circuit port.On the basis of the characteristic curve of each transistor of the port measured or extracted based on the IBIS model,the model parameters are extracted by using the derived diode and MOS transistor model.These models fully take into account the second-order effects such as parasitic resistance,velocity saturation and channel length modulation.Finally,according to the input and output port circuit structure,the device port physical model is built by using VHDL-AMS language and data flow modeling method.(4)Total dose effect modeling of CMOS digital integrated circuits.In this thesis,the mechanism of total dose effect of MOS devices is studied,and the threshold voltage drift and carrier mobility degradation model of MOS devices caused by total dose ionizing radiation are established.In this thesis,the total dose effect model of digital integrated circuits is established by integrating the total dose effect threshold model and carrier model of MOS devices into the port physical model and establishing a functional area model to describe timing degradation.Through experimental comparison,the functional correctness and feasibility of the model are verified.To sum up,this thesis focuses on the total dose effect modeling of CMOS digital integrated circuits,and studies the whole modeling process systematically and comprehensively.It solves the problems of difficult acquisition of physical model,high complexity of simulation and poor applicability of behavioral model environment,and provides a way and reference for anti-radiation design and research of digital integrated circuits.