Epitaxial MOCVD of Thin Film Ceramics for Pyroelectric Detectors

摘要

The objective of this research is to increase the sensitivity of pyroelectricdetectors by growing a thin-film single crystal of lead-titanate (PTO) on cobalt-silicide (CoSi2) on silicon using metalorganic chemical vapor deposition (MOCVD). A thermal isolated, aligned film should increase detectivity. In Phase I of this research Spire demonstrated MOCVD of PTO on CoSi2 on silicon by MOCVD using a diffusion barrier between the films. Small capacitors were fabricated and the dielectric constant was formed to vary with temperature as expected. Multiple films were required to preserve the heteroepitaxial crystal structure while preventing chemical interactions and interdiffusion. Formation of silicon-dioxide prevents direct deposition of epitaxial oxide films on silicon, so that CoSi2 was deposited first. This was followed by laser ablation deposition of the conducting film yttrium-barium-copper-oxide to prevent inter-diffusion of lead. The PTO film was then put down by MOCVD, and the structure was verified by X-ray diffraction.