Research On Simulation Of Radiation Hardened CMOS Devices

With the rapid development of China's military industry and aerospace technology,more and more electronic equipment should be used in various radiation environments,in the environment of space and nuclear test,there are various kinds of high-energy particles radiation.Therefore,radiation reinforcement measures must be taken for the integrated circuit in this application scenario.The anti radiation strengthening technology of integrated circuit is closely related to national security and national defense construction.Strengthening the research of anti radiation strengthening technology can break the technology monopoly of high-end anti radiation devices,which is very important for national security and national defense construction of our country.Sentaurus of Synopsys company is used in many device simulation researches in China TCAD semiconductor technology and device simulation tool,which contains a lot of physical models and material parameters,is oriented to various semiconductor related simulation problems.For the research of total dose effect resistance,the method of adding positive fixed charge directly into gate oxide and field oxygen materials is generally used to accumulate the oxide trap charge and interface trap caused by radiation of the simulator With the increase of well charge,the relationship between the number of positive fixed charge and the irradiation dose,and the distribution of fixed charge in the material are quite different from the actual situation.In this paper,we use Cogenda's Genius,gds2 mesh,VisualPartial and other simulation software to study the radiation reinforcement technology,which is different from Sentaurus TCAD simulation software,The numerical simulation and engineering technology of radiation effect in semiconductor devices are the focus of Cogenda company,especially in the research of anti total dose effect,which is different from the method of adding positive fixed charge directly in the Sentaurus TCAD.The related software of Cogenda uses direct irriadiation to study the total dose effect.The amount of irradiation dose will generate corresponding amount of trap charges in the gate oxide layer and field oxygen of the device,and the distribution of trap charges is also obtained by numerical simulation,which is closer to the generation mechanism of the total dose effect in actual situation.Because of the new algorithm semi implicit solver,the calculation speed is faster than the traditional algorithm.Based on the irradiation reaction mechanism and the basic principle of total dose effect,which is closer to the actual situation of Cogenda's semiconductor simulation software,this paper studies the physical process of total dose effect and the effect of total dose effect on the electrical characteristic parameters of MOS devices,and studies several anti total dose reinforcement measures from the angle of device structure,including:1.The P + doping region is formed on both sides of the source region of the general NMOS transistor,which makes the transistor have the ability of anti total dose effect performance.2.The active area of NMOS transistor is enlarged longitudinally and N + source and drain area is implanted selectively,so as to improve the anti total dose effect performance of the transistor.3.The double gate structure is used to improve the radiation resistance of NMOS transistors,in which the thin gate suppresses the threshold voltage drift and the leakage current increase.4.On the basis of SOI device structure,a P + region is added under the source region of NMOS device to weaken the back gate effect and floating body effect of SOI device,so as to improve the anti total dose effect performance of transistor.5?Study on the total dose effect of a new type of NMOS device structure with vertical channel and ring gate.The first four of the above structures are radiation-hardened methods,it is based on the existing bulk silicon CMOS device structure and SOI device structure.Through the simulation platform of Cogenda,the total ionizing dose effect simulation of the first four kinds of radiation-hardened NMOS transistors and their corresponding common NMOS transistors is carried out respectively.By comparing the relevant parameters extracted from the simulation results,it can be seen that the first four kinds of radiation-hardened methods can effectively improve the anti total dose effect performance of the device.The fifth device is an exploration of the new device structure,which is totally different from the existing CMOS device structure.On the basis of its normal transfer and output characteristic curve,the anti total dose effect performance of the new device is preliminarily studied,from the simulation results,it can be seen that the new device structure also has good anti total dose effect performance.