Research On Transient Dose Rate Effect Of FinFET SRAM

With the vigorous development of space industry,people are increasingly aware of the fact that transient radiation damage in the electronic system caused by energetic particles in the radiation environment,can not be ignored,and radiation-induced soft errors and even permanent damage are a serious threat to the reliability of the electronic system.At present,3D Fin FET devices replacing the planar MOSFET devices become mainstream technology with the semiconductor process node entered the 14 nm.Considering the change of the radiation effect caused by the structural difference between the Fin FET and the traditional planar MOSFET and the SRAM as the most sensitive part of the radiation in the integrated circuit,the transient dose rate effect simulation of Fin FET SRAM is carried out.Based on the radiation damage mechanism of transient dose rate effect,a simulation method of transient dose rate effect is proposed,which is Geant4 software simulating particle transport,Sentaurus TCAD software simulating the transient current of devices and HSPICE simulating the flip of SRAM cell.The three-dimensional model of Fin FET device was established by reference to BSIM-CMG model.The transient dose rate effect of SOI and bulk Fin FET SRAM is studied,and the anti-transient radiation performance of two kinds of Fin FET devices is compared.The transient radiation sensitivity of Fin FET and planar 65 nm MOSFET devices is compared,and the anti-transient radiation flip ability of three classical radiation hardened cell is evaluated.The achievements of this paper are as follows:1.Based on the 3D model of Fin FET device,Geant4 is used to simulate the particle transport of different number of gamma particles in the device.The energy deposition in the device is calculated and converted into LET.Using the Sentaurus TCAD radiation model parameter LET,an equal amount of energy deposition is added to the device to simulate the transient current caused by the radiation of the device.The results show that the transient current of the SOI Fin FET device is smaller than that of the bulk Fin FET device in the case of the same number of incident particles because the SOI Fin FET can not collect the charge generated by the substrate due to the presence of the buried oxygen layer.2.Using HSPICE to add the transient current to the SRAM cell sensitive nodes to simulate the transient radiation of gamma.Comparing the simulation results of SOI Fin FET and bulk silicon Fin FET SRAM,it is concluded that SOI Fin FET has better ability to resist transient radiation.The simulation results show that the flip threshold LET is 0.0104 p C/μm and the critical charge is 0.76 f C,which is comparable to the threshold LET of 0.0112 p C/μm and the critical charge of 0.73 f C of the 14 nm bulk Fin FET in [36].3.In order to compare the transient dose rate effect of Fin FET with planar device,the transient dose rate effect of planar 65 nm MOSFET SRAM cell is simulated,and the threshold LET is 0.0096 p C/μm,which is smaller than that of Fin FET SRAM.It is concluded that Fin FET devices has better ability to resist transient radiation than planar 65 nm MOSFET devices.The main reason is that planar 65 nm MOSFET devices have bigger sensitive volume than that of Fin FET devices,thus deposit more energy and generate more charge.4.The existing radiation hardened technology is summarized.Through the simulation analysis of DICE cell,ROCK cell and 10 T cell for resisting single-node flip and double-node flip,the conclusion that ROCK cell has better anti-radiation ability is obtained.