Modeling And Numerical Simulation Of Total Ionizing Dose Irradiation Effect On Ferroelectric Field-effect Transistor

Information storage plays an important roll in the development of aviation and space technology,which is closely related with the development in the field of aerial and space.Ferroelectric memory is one of the most promising memories because of many advantages such as high speed,high endurance,and low operating voltage.Ferroelectric field effect transistor(FeFET)as one of the structures of ferroelectric memory has attracted much attention in aerospace with advantages such as nondestructive read-out,high density,and simple structure.In aerospace applications,FeFET will be inevitably affected by the cosmic rays and space radiation particles,leading to the phenomenon of performance reduction,state changes,and function failure.In this thesis,basic electrical characteristics and retention properties of Metal-Ferroelectric-Insulator-Silicon field effect transistor(MFIS-FET)and Metal-Ferroelectric-ZnO field effect transistor(MFZ-FET)under total ionizing dose irradiation for are investigated theoretically.The main contents and conclusions are as follows.(1)On the basis of Lue model for ferroelectric polarization,a physical model about electrical characteristics of MFIS-FET under total ionizing dose irradiation is set up,and the I-V and C-V curves of MFIS-FET under the different dose are simulated and analyzed.With the increase of dose,the polarization,coercive field and dielectric coefficient of ferroelectric layer decrease,which directly affect the performances of the entire device,such as the negative drift of C-V curve,the decrease of memory window,and the on/off ratio and drain current.(2)Combing Lou model for the retention characteristic of ferroelectric film with the above-mentioned electrical model under total ionizing dose irradiation,a retention model of MFIS-FET under total ionizing dose irradiation is set up.The total ionizing dose irradiation effect of retention characteristics for MFIS-FET is investigated.With the increase of dose,the depolarization increases and retention characteristic becomes worse due to the radiation-induced charge accumulation.(3)A physical model about electrical properties of MFZ-FET under total ionizing dose irradiation is set up by using the above-mentioned modeling approach,and the I-V and C-V curves of MFZ-FET under the different dose are simulated.By comparing electrical properties of MFZ-FET and MFIS-FET under total ionizing dose irradiation,it is found that the anti-radiation of MFZ-FET is superior to that of MFIS-FET.