Total Ionizing Dose Effect Of Ferroelectric Random Access Memory Under Co-60 Gamma Rays And Electrons

As the development of space aerospace technology,the requirement on the reliability of semiconductor integrated circuits in space satellite electronic systems,becomes higher than ever.In a complex space environment,semiconductor memory device in space satellites will be influenced by charged particles such as electrons and protons.The storage device undertakes the task of preserving a wide variety of research data.However,the failure of the memory function caused by the total ionizing dose effect will be caused data loss and affect the orbital operation of the spacecraft.In recent years,the important researches are exploring the ionization total ionizing dose effect damage mechanism of memory and improving radiation resistance of memory.As a new type of memory that the data can be maintained after power-off,ferroelectric memory has many strong points such as low power consumption,long life,high reading and writing speed.In addition,ferroelectric thin film materials have excellent radiation resistance,so they are confirmed to satisfied the space environments.At present,the problem is that our research on the total ionizing dose effect of ferroelectrics are mainly focused on ferroelectric thin film materials,while the device-level research is insufficient.Therefore,taking 130 nm FeRAM as our research object,the ionizing radiation effects of electrical parameters of the FeRAM devices online and offline were studied by means of Co-60 gamma rays and 2 MeV electrons,including the impacts of working conditions and radiation sources.The research contents of this paper include:(1)The ionizing radiation effects of FeRAM were studied by means of different test conditions and the relationship between radiation damage and working state is obtained.The results indicate that the differences in the electric field can result in different generation and recombination rates of electron/hole pairs.The radiation damage at static biased is most serious.And the oxide trap charge is responsible for device recovery during normal temperature annealing.(2)The total dose effect of the electrical parameters of the ferroelectric memory under the static power-on mode was studied.The total dose radiation sensitivity parameters of the ferroelectric memory were obtained and a quantitative analysis method was proposed.The results show that in the process of irradiation,with the leakage current increase caused by ferroelectric capacitor and transistor,the standby current is increasing.Finally,the electrical parameters are failure.And through analyzing the results,it can be seen that the standby current and the leakage current are sensitive to TID effects.Meanwhile,the QMU analysis of the electrical parameter test results found that the standby current is smaller than the failure threshold of the leakage current and the standby is more sensitive to TID effect.(3)The electronic ionizing radiation effect was carried out on a 2 MeV electron accelerator,and the failure threshold of the device under electron radiation was obtained.Besides,the threshold of device damage caused by electron radiation was compared with that caused by Co-60 gamma.The experimental results show that the electrons interact with the device in an inelastic collision,and the loss of the sense amplifier in the peripheral circuit eventually leads to device failure.Furthermore,by comparing the results induced by the two different radiation sources,it can be seen that electrons induced less severe TID degradation.Furthermore,by comparing the results induced by the two different radiation sources,it can be seen that electrons induced less severe TID degradation compared to Co-60 gamma rays.The reason should be the lower net production rate of electron/hole pairs.