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 x 10(8) to 2.38 x 10(8) cmHz(1/2)/W with an increase of heating rate from 600 to 1800 degrees C/min. However, the voltage responsivity and the specific detecivity decrease with heating rate in excess of 1800 degrees C/min. The results show that the LiTaO3 thin film detector with a heating rate of 1800 degrees C/min exists both the maximums of voltage responsivity and specific detecivity.