High Specific Detectivity Infrared Detector using Crystal Ion Slicing Transferred LiTaO3 Single-crystal Thin Films

Abstract LiTaO3 (LT) single crystalline films have been used to fabricate pyroelectric infrared detectors. Sub-micrometer thick LT films have been transferred on LT holder substrate by Crystal Ion Slicing (CIS) technology using hydrogen ions implantation and SiO2 bonding process. The surface roughness result from the Gauss distribution of hydrogen ions was decreased from 18.7 nm to 1.5 nm after Ar+ ion bombardment. The pyroelectric coefficient of CIS fabricated LT film (2 × 10−8 C/cm2·K) is comparable to that of LT bulk crystal. Detectors fabricated using the CIS fabricated LT films show larger detectivity at higher modulation frequency than the commercially available pyroelectric devices using LT bulk crystal or PZT polycrystalline thin films. The highest value of specific detectivity is 2.49 × 108 cm·Hz1/2W−1 at 300 Hz. The results demonstrate that the LT single crystal film fabricated by CIS technology is a promising material to fabricate quick response pyroelectric devices.