Defect Behavior Of Irradiated CZ Silicon

With the development of microelectronic technology,silicon materials are widely used in the integrated circuits,which require a very high standard.In the irradiation environment,silicon semiconductor devices will get different levels of damage,including ionization damage induced by low energy irradiation and displacement damage induced by high energy irradiation,which will reduce the service life of devices and even lead to device failure.As more and more semiconductor devices are used in space,nuclear radiation,high-energy electromagnetic fields and other environments,irradiation damage is inevitable.Therefore,the research on the irradiation effect of monocrystalline silicon materials has very important theoretical significances and practical values for the development of new irradiation impurity absorption process.However,defects of the silicon-based interface state caused by ionization damage and kinetics behavior of vacancy-oxygen evolution induced by displacement damage are not well studied.In this paper,transient capacitance,isothermal annealing,nano-indentation and other methods were used to study the interface state of?-ray irradiated silicon-based MOS structure,the effect of nitrogen doping on the vacancy-oxygen complexes in fast neutron irradiated monocrystalline silicon and the effect of irradiation on the mechanical properties of silicon materials,and the following results were obtained:?1?This paper tested the transient capacitance of silicon-based MOS structures at different temperatures by using deep level transient spectrum?DLTS?,and we found that?-ray irradiation can increase the state density of SiO₂/Si interface by 6-8 times and increase the capture cross section of the interface state to the holes by 5-6 orders of magnitude.?2?Nitrogen doping can affect the kinetics of vacancy-oxygen complexes on neutron irradiated monocrystalline silicon.The main performances are as follows:nitrogen doping can introduce tensile stress into the silicon lattice which improves the diffusion rates of vacancy?V?and VO complex.The reduced activation energy of VO annihilation from 2.08 eV to 1.84 eV,and activation energy of VO₂ generation from 1.47 eV to 1.23 eV,thus promoting the process of VO to VO₂ complex.?3?Large doses of neutron irradiation can introduce a large number of vacancy defects into monocrystalline silicon,damaging the lattice position of silicon atoms and reducing the binding energy between atoms.In the loading and unloading process of nano-indentation test on neutron irradiated monocrystalline silicon,the Si-I phase is more easily transform to Si-II phase,which results the higher hardness and lower Young's modulus.