Preparation and Characterization of Novel Lithium Tantalate Target

Abstract

The novel lithium enriched lithium tantalate (LiTaO3) targets were papered by employing the sol-gel process and the high temperature sintered process. The sol of LiTaO3 was firstly prepared through reacting lithium ethoxide with tantalum ethoxide. The LiTaO3 powder was fabricated by presintered LiTaO3 dry gel 4 hour, at 800°C. The 11cm13cm1cm lithium enriched LiTaO3 target samples were prepared by sintered the pressed LiTaO3 powder billet 4 hour in the 850°C muffle furnace. The density of the 5% overdose lithium enriched LiTaO3 target is measured 5.96g/cm3. The XRD measured results show that the ion beam enhanced deposited (IBED) thin film samples using the prepared 5% overdose lithium enriched LiTaO3 target have the polycrystal structure of LiTaO3, but there has remanent Ta2O5 existed in the IBED thin film samples. The main reason for the remanent Ta2O5 growth was due to the stoichiometric proportion mismatch between Li and Ta in the IBED thin film samples during the high temperature annealed process, which caused the lithium oxide evaporation loss from the IBED thin film samples and made the proportion of Ta2O5 increase. After multipule repeated target prepared experiments, the 8.76% overdose lithium enriched LiTaO3 target is suitable for fabricating the 550°C annealed IBED LiTaO3 thin film. After the repeated process experiments, the suitable deposited process parameters of the IBED-C600M instrument for the 8.76% overdose lithium enriched LiTaO3 target were obtained. The SEM micrographs of the 550°C annealed IBED LiTaO3 thin films prepared by the 8.76% overdose lithium enriched LiTaO3 target reveal the prepared thin films are uniform, smooth and crack-free on the surface, and the perfect adhesion between the thin film and the substrate. The successfully fabricated LiTaO3 thin film samples verify the prepared processes of novel LiTaO3 sputtering target are effective.