Ion Assisted Deposition Of Thin-film Characteristics

In this dissertation, thin films are deposited on K9 glass substrates using an e-beam gun evaporation with low energy oxygen ion assisted deposition (IAD) from an end-Hall ion source. A comparison of the optical and mechanical performance is made between with IAD and without IAD.The researched thin films includes monolayer thin films and multilayer thin films.1. The research of monolayer thin filmsIn the paper, Three mololayer thin films- TiO2 Ta2O5 Nb2O5 oxide dielectric thin films are studied. A comparison of the optical and mechanical performance is made between with IAD and without IAD.The optical performances include the refractive index the extinction coefficient the packing density the vaccum-to-air shift and the AFM images of the surface;The mechanical performances include the adhesion and the hardness. We observe that films deposited with ion assist are much more profitable than those deposited without ion assist. The IAD increases the packing density of Nb2O5 films by 14%, hence the refractive index arises from 2.03 upto 2.18 and the adhesion arises from about 1 X 107N/m2 to 129.7X 107N/m2; The IAD increases the packing density of Ta2O5 films by 13%, hence the refractive index arises from 2.03 upto 2.23; The IAD increases the packing density of TiO2 films by 20%, hence the refractive index arises from 2.03 upto 2.37.2. The research of multilayer thin filmsZnS/MgF2, Nb2O5/SiO2% TiO2/SiO2 narrow band interference filters are deposited by IAD with an end-hall ion source. Compared to the specimens produced by conventional process deposition, we discover that spectral shift (△λ) of the filter is reduced obviously by using IAD. The typical result shows that the spectral shift of ZnS/MgF2 narrow band interference filters is less than 0.5nm. The formula for estimating packing density of the films was put forward in terms of the measured △ λ. and the packing density of MgF2 layers in the filters was calculated. The calculated density of MgF2 with IAD was increased from 0.70 for conventional process to 0.97. Meanwhile we find that the spacer layer has a great influence on the spectral shift. The further the layers are away from the spacer, the less the effect; In the same way, the IAD reduces the spectral shift of Nb205/SiO2 narrow band interference filters from 29.4nrn to 12.4nm; The IAD reduces the spectral shift of TiO2/SiO2narrow band interference filters from 24.7nm to 8.4nm.In conclusion,we observe that both monolayer thin films and multiplayer thin films deposited with ion assist are much more profitable than those deposited without ion assist.