Orientation effect on microwave dielectric properties of Si-integrated Ba0.6Sr0.4TiO3 thin films for frequency agile devices

Abstract

The effect of texture with (100) and (110) preferred orientations on dielectric properties of Ba0.6Sr0.4TiO3 (BST) thin films grown on SrO (9 nm) and CeO2 (70 nm) buffered Si substrates, respectively, was investigated. The coplanar waveguide (CPW) phase shifter using (100) oriented BST films on SrO buffered Si exhibited a much-enhanced figure of merit of 24.7 degrees/dB, as compared to that (10.2 degrees/dB) of a CPW phase shifter using (110) oriented BST films on CeO2 buffered Si at 12 GHz. This work demonstrates that the microwave properties of the Si-integrated BST thin films are highly correlated with crystal orientation. (c) 2006 American Institute of Physics.