Study On Radiation Mechanism And Simulation Technology Of Deep Sub-micron Devices

As the core device,integrated circuits with high integration and reliability have become a major factor restricting the performance improvement of our country's space crafts and weapons which radiation environment.With the continuous progress of CMOS technology,the size of integrated circuits has reduced and integration is rising,which lead to obvious radiation damage.At the same time,the radiation coupling effect in complex space environment makes the conclusion of the device and circuit damage which is obtained under the assumption of single effect not be coincident with the actual situation.What's more,it improves the difficulty in the exploration of electronic system of radiation damage mechanism and the development difficulty of increasing the reinforcement technique against radiation.Studying the failed mechanism and radiation effect model technology of the deep sub-micron devices in the radiation environment is to reveal the radiation damage mechanism of the devices accurately and completely.So it is necessary that the simulation methods should be developed to coordinate multiple factors coupling effect effectively.Based on the necessity,the research on the radiation mechanism and simulation technology of deep sub-micron devices based on coupled radiation effect is carried out in this paper.The main research contents are as follows:(1)A single event effect model of pulsed laser-equivalent heavy ion LET threshold is proposed in this dissertation,which provide a new means for simulation of single event effect.Based on depth analysis of physical mechanism of single event radiation effect,the model takes the factors such as the refractive index and transmittance of the incident energy of laser beam and the modulation effect of SiO2 layer into consideration.It improves the energy loss function as far as possible,so as to enhance the accuracy of pulsed laser-equivalent heavy ion LET threshold model;(2)The total dose radiation effect model has been improved and perfected in this dissertation,and it improves according to the relationship between total dose radiation effect model and radiation times,device structure.The model adopts the discrete time,which consider the factors such as energy decay,initial electric field and changing electric field of the charge accumulation process so as to enhance the accuracy of the total dose radiation effect model.(3)Based on the single event effect model of pulsed laser-equivalent heavy ion LET threshold and the improved total dose radiation effect model,the software program has been made,which supports the single event effect and total dose effect.In the process of development,the single event effect model introduces the transmittance function to improve the laser energy correction to calculate the equivalent heavy ion LET threshold.The total dose model uses the discrete-time cumulative iteration algorithm to calculate the cumulative hole number.On this basis,the software program and Sentaurus TCAD software are combined to form a simulation platform,and a simulation platform of single particle and total dose effect simulation are built.(4)Based on the above platform,the CMOS device single-particle and total dose-effect collaborative simulation was validated and analyzed.The dissertation respectively simulated the single event radiation effect under 0Krad,200 Krad and 800 Krad total dose radiation based on the 45 nm NMOS three-dimensional devices,then compared and analyzed the simulation results of these three groups.The analysis results show that the larger the value of total dose radiation is the more easily the single event effect will occur under the same LET energy of a single event incident condition,and the effect of total dose radiation on the single event effect will be reduced,when the single event radiation effect is strong.Simulation indicated the proposed models and TCAD simulation platform can predict the performance under the coupled effect of single event effect and total dose effect in deep sub-micron CMOS devices.The feasibility of the program and the simulation platform is verified.