Dielectric properties of sol-gel derived CaCu_3Ti_4O_(12) thin films onto Pt/TiO_2/Si(100) substrates

摘要

The ultrahigh relative dielectric constant (K') values reported for the CaCu_3Ti_4O_(12) bulk ceramics (10~4 at RT) joined to their low thermal dependence, no phase transitions are expected between -173 and 330 deg C, make this material very promising for capacitor applications and certainly for microelectronics. The interest in the preparation of this material in thin film form is twofold, the understanding of its physical properties and the integration of this high K' oxide with the Si technology. In this work, the preparation of CCTO thin films onto Pt/TiO_2/SiO_2/Si(100) substrates is attempted using sol-gel processing and rapid thermal processing (RTP) at 650 deg C. Structural, microstructural and dielectric characterization of the films is performed. The results are commented and discussed on the light of the grain boundary effect on the dielectric constant and the possibility of application of these thin films in microelectronic devices.