Simulation Of Single Event And Total Ionizing Dose Radiation Characteristics Of TFET Based On FDSOI

With the development of integrated circuits,the feature size of devices is dereasing and the working voltage on chips is also decreasing.Because of the features of low subthreshold swing,high current switching ratio and low subthreshold leakage current,TFET has become one of the most potential new devices in the field of low voltage and low power consumption.In addition,with the development of China's aerospace industry,the technical demand for the reliability of some low characteristic sizes,new devices and new circuits is also increasing.In order to make TFET devices better used in aerospace field,this paper mainly carries out the research on TFET device based on FDSOI and its irradiation characteristics.The charge collection mechanism of TFET device under single particle irradiation and the performance degradation of TFET device under total dose irradiation are studied for the first time.The main research contents are as follows:Firstly,the performance of TFET device is studied:the performance of the device is simulated from two aspects:semiconductor technology(the doping of source region?the doping of drain region)and structure of device(the overlapping length of gate to source,the thickness of sidewall),it is found that:when the doping concentration of source region reaches1×10²¹cm^-3,the on-state current can reach 5×10^-6A/?m,however,the switching ratio I_on/I_offwill decrease from 10¹¹ to 10⁸ and the threshold voltage of device will drop from 1.2V to0.6V.In addition,the subthreshold swing of the device will be slightly reduced by appropriately increasing the doping concentration of drain region.When the gate of device overlaps source region,the on-state current can be significantly increased because of the line tunneling mechanism being introduced,but the gain of current tends to saturate with the increase of the overlapping length.At the same time,the reduction of the thickness of sidewall can also increase the gate dispersion field's control on the barrier region of tunneling junction,reduce the width of the line tunneling barrier and increase the on-state current.The optimal thickness of sidewall is about 2nm.Secondly,the single event transient effect of TFET device is studied:The sensitive position of the device is analyzed by simulating different position of incident,depth of incident and angle of incident.It is found that the channel region in the silicon film,especially the barrier region at both ends,is most sensitive to the single event transient effect.And the mechanism of charge collection in sensitive position is simulated and analyzed.In addition,the anti single event transient performance of the device under different bias of drain and bias of substrate is simulated and analyzed.Finally,in the light of the high peak current of single event transient effect in TFET device,the reinforcement simulation is carried out from two aspects:the thickness of silicon film and the doping concentration of drain region.Lastly,the total ionizing dose effect of TFET device is studied:The damage of the BOX layer is compared and analyzed when the device is biased in on-state,off-state and TG state.It is found that the damage of the BOX layer is the most serious when the device is in the off-state,and it is found that the ionization rate of the BOX layer near the source region is the highest regardless of the bias.Then the current switching ratio I_on/I_off,the probability of band to band tunneling,threshold voltage,subthreshold swing and bipolar effect of the device under different irradiation doses are analyzed.Finally,the effect of the thickness of BOX layer on the total ionizing dose effect of the device is simulated and analyzed.The results show that the ability of anti total ionizing dose effect is the strongest when the thickness of the BOX layer is about 20nm and 120nm,and the ability of anti total ionizing dose effect is the worst when the thickness of the BOX layer is about 60nm,which provides a reference for the subsequent reinforcement of total ionizing dose effect in circuit level.