The Diffusion And Interface Reaction Of Cu And Si Systems

The Cu films are deposited on Si substrates by magnetron sputtering and ionized cluster beam technique(ICB).The interface reaction and atomic diffusion of the Cu films and Si substrates as deposited and annealed at different temperature are studied by Rutherford backscattering spectrometry(RBS).The results are analyzed by the reaction diffusion theory and silicides growth theory, and the diffusion coefficients are calculated.This work obtained some significant results on the following aspects:1.The onset temperature of interdiffusion was 450℃for the Cu/SiO₂/Si(111) systems.With the increase of temperature,the interdiffusion was more apparent. There are no copper silicides formed below 450℃,at higher temperature Cu reacted to Si to form copper silicides.The diffusion and interface reaction of Cu/SiO₂/Si(111)systems are suspressed by the existence of native SiO₂ layers,are harder than Cu/Si systems.2.The onset temperature of interdiffusion was 350℃for the Cu/SiO₂/Si(100) systems.With the increase of temperature,the interdiffusion was more apparent. There are no copper silicides formed below 350℃,at higher temperature Cu reacted to Si to form copper silicides.The diffusion and interface reaction of Cu/SiO₂/Si(100)systems are easier than Cu/SiO₂/Si(111)systems,it depended on the orientation of the Cu films and Si substrates.3.The results of the Cu/SiO₂/Si(111)systems prepared by neutral cluster beam and ionized cluster beam accelerated at Va=3 kV are similar to the Cu/SiO₂/Si(111)systems prepared by magnetron sputtering.The onset temperature of interdiffusion and interface reaction was 450℃,and the copper silicides are formed.4.The results of the Cu/SiO₂/Si(111)systems prepared by neutral cluster beam are similar to the Cu/Si systems.When annealed at 230℃,the diffusion and interface reaction of Cu films and Si substrates can be observed,the copper silicides are formed. 5.The diffusion of Cu/Si(111)systems prepared by ionized cluster beam accelerated at Va=3 kV can be observed as Cu films deposited.With the increase of temperature from 230℃to 600℃,there are no apparent differences in RBS spectrum.And no copper silicides phase can be observed in XRD spectrum,there are no copper silicides formed.So we think that a thermally stable intereface are formed between the Cu films and the Si substrates.