Optical Properties of LiTaO3 Thin films crystallized by RTA processes

High-performance pyroelectric infrared detectors have been fabricated using Lithium tantalite (LiTaO₃) thin films deposited on Pt(111)/Ti/SiO₂/Si(100) substrates by diol-based sol-gel method and rapid thermal annealing (RTA) technique. The dielectric and pyroelectric properties of IR detectors of LiTaO₃ thin films crystallized by conventional and RTA processes are investigated. Experimental results reveal that the heating rate will influence strongly on dielectricity and pyroelectricity of LiTaO₃ thin films. The voltage responsivities (Rv) measured at 80 Hz increase from 5496 to 8455 V/W and the specific detecivities (D^∗) measured at 300 Hz increase from 1.94 × 10⁸ to 2.38 × 10⁸ cmHz^1/2/W with an increase of heating rate from 600 to 1800^∘C/min. However, the voltage responsivity and the specific detecivity decrease with heating rate in excess of 1800^∘C/min. The results show that the LiTaO₃ thin film detector with a heating rate of 1800^∘C/min exists both the maximums of voltage responsivity and specific detecivity.