Study On The Electron And Heavy Ion Radiation Defects Of SiO₂ Film For Gate Dielectric

Various types of spacecraft widely use electronic components.During orbiting,electronic components using SiO₂ as the gate dielectric are very sensitive to the environment of charged particles.However,there is currently a lack of in-depth research on the formation and evolution mechanism of radiation defects in SiO₂ gate dielectric materials.In this paper,electrons and heavy ions of different energies are used to irradiate SiO₂ films for gate dielectrics with different passivation processes.Based on Raman scattering spectroscopy,transmission electron microscopy and photoluminescence spectroscopy,the radiation of different types of particles is studied.And the influence mechanism of different passivation processes on the radiation defects of SiO₂ film used in the gate dielectric.The research results show that under the same irradiation fluence,compared with the unirradiated sample,both 90 keV and 150 keV low-energy e lectron irradiation will significantly increase the single-level neutral oxygen vacancy(?Si-Si?)defects in the SiO₂ film.In addition,150 keV electron irradiation resulted in the formation of dioxygen ions inside the SiO₂ film,and at the same time,the formation of pure silicon clusters in the range of?5 nm from the surface;When low-energy silicon ions and oxygen ions are irradiated,defects such as multi-level neutral oxygen vacancies in the SiO₂ film have increased significantly and dioxygen ions are formed.In addition,400keV silicon ion irradiation will cause pure silicon clusters to form inside the SiO₂ film.However,300 keV and 400 keV oxygen ion irradiation will not cause pure silicon clusters to form in the film;1 MeV electron irradiation causes a large increase in defects such as multi-level neutral oxygen vacancies in the SiO₂ film,and the formation of dioxygen ions and pure silicon phase clusters.The formation and evolution of internal radiation defects in the SiO₂ film for the gate dielectric when irradiated by different kinds of particles are all due to the incident particles causing the Si-O bond to break,which in turn leads to the formation of various radiation defects.However,when different particles are irradiated,the Si-O bond breaks in different ways:90 keV electrons cause Si-O bond breakage only through ionization;150 keV electrons cause the Si-O bond to break or weaken the Si-O bond through ionization to cause the displacement of oxygen atoms;The displacement of low-energy heavy ions causes the displacement of silicon and oxygen atoms to break the Si-O bond;1 MeV electrons can cause the Si-O bond to break or weaken the Si-O bond to displace the oxygen atom through ionization,but also directly cause the oxygen atom to displace and break the Si-O bond.Compared with before irradiation,after 1 MeV electron irradiation,I passivation process SiO₂ film when the irradiation fluence reaches 1×10¹⁶ e·cm^-2,dioxygen ions and pure silicon phase clusters are formed inside the SiO₂ film;In the II passivation process SiO₂ film,when the irradiation fluence reaches 5×10¹⁵ e·cm^-2,dioxygen ions and pure silicon phase clusters are formed inside the SiO₂ film.For the III passivation process,under different fluence irradiation conditions,the SiO₂ film only showed a slight increase in defects such as neutral oxygen vacancies.In addition,the formation mechanism of high-energy electron radiation defects in the SiO₂ film for gate dielectrics of different passivation processes is basically the same as that of the SiO₂ film for gate dielectrics without passivation layer.