Anti-irradiation Characteristics Of MOSFET And Its Application

With the rapid development of integrated circuits since the 21st century and the human footsteps towards space exploration,more and more complex chips have been applied in the aerospace field.Both the complex radiation environment in space and the nuclear radiation environment on the ground have posed huge challenges to the reliability and stability of electronic devices.This thesis focuses on the current development status of integrated circuits and the important background of China’s aerospace industry,and conducts in-depth research and analysis on the radiation effects of integrated circuits and their reinforcement measures.This thesis first introduces the radiation environment in which electronic devices are located,explains the theoretical basis of transistor radiation effects,and explains the two important physical quantities of linear energy transfer（LET）and dose in the mechanism of target material damage caused by high-energy particles.It also elaborates on the mechanisms of total ionizing dose（TID）effect,single event effect（SEE）,and their impacts on electronic devices.This thesis conducts in-depth research and analysis on TID and single-event latch（SEL）effects using various methods such as irradiation experiments and software simulations.Regarding TID effects,this thesis analyzes in depth the TID experimental results of source region edge P+doped NMOS transistors,fits the experimental results using Sentaurus TCAD simulation software,and analyzes the reasons for the increased leakage current of source region edge P+doped NMOS transistors under high-dose irradiation based on the simulation results.This thesis proposes a substrate-reinforced source region edge P+doped NMOS transistor and verifies its effectiveness through simulation.The simulation results show that the transfer characteristic curve of the newly hardened NMOS transistor has almost no change at a total dose of up to 1.8 Mrad（Si）.This thesis further extends the source region edge P+doping reinforcement scheme and substrate reinforcement scheme to Fin FET,and proves their feasibility and effectiveness through simulation software.The simulation results show that the off state leakage current of the hardened Fin FET can be maintained at the order of 1×10^-9A when the total irradiation dose reaches 1.5 Mrad（Si）.As for SEL,this thesis uses the heavy ion model in Sentaurus TCAD simulation software to simulate the latch-up effect of four types of inverters,analyzes the simulation results,and demonstrates the effectiveness of the reinforcement scheme.The three reinforcement structures increased the LET value of latch occurrence from 21.12 Mev×cm²/mg to 66.24 Mev×cm²/mg,163.2 Mev×cm²/mg,and no latch effect occurred.Based on the experimental and simulation results,this thesis proposes the rules of anti-irradiation reinforcement of commercial process library,and uses the rules to reinforce the digital logic basic unit of a 0.11μm CMOS process in a chip factory.The simulation analysis is carried out from the area,power consumption,performance and other aspects to the basic unit after reinforcement.The analysis shows that after the basic unit is processed by the reinforcement rules proposed in this thesis,the area of the layout size increases by about 20%～40%,the transmission delay changes in the order of ps and the power consumption increases in the order of n A.The functional characteristics are normal.