Dielectric property of Ion Beam Enhanced Deposited lithium tantalate thin film infrared detector

The Ion Beam Enhanced Deposited (IBED) LiTaO₃ thin film infrared detectors with Al/LiTaO₃/Pt structure were prepared on the Pt/Ti/SiO₂/Si(100) substrate. The crystallization, the film thickness, the dielectric properties, the leakage current and the anti-breakdown ability of the IBED LiTaO₃ thin film infrared detector samples were investigated by the different annealing processes. The XRD measured results show that, the prepared samples have the polycrystal structure of LiTaO₃ with the preferred orientation of <;012>; and <;104>; located at the 2theta of 23.6° and 32.7° respectively. The residual Ta₂O₅ has been existed in the prepared samples owe to the Li volatilization during the high temperature annealing process. The obtained 587nm thick IBED LiTaO₃ thin film infrared detector sample annealed at 550°C has the dielectric permittivity of 39.44, the low dielectric loss of 0.045 at the tested frequency of 100 kHz, and the small current leakage of 4.76×10^-8A/cm² when subjected to the tested electrical field of 400kV/cm. The electrical breakdown experimental results show that the prepared detector samples have strong ability of anti-breakdown and can be subjected to the stronggest electrical field of 680kV/cm. The experimental results show that, the dielectric loss and the leakage current of the IBED LiTaO₃ thin film infrared detectors are better than those of the Sol-Gel derived LiTaO₃ thin film infrared detectors.