Improvements in tunability of (Ba0.5Sr0.5)TiO3 thin films by use of metalorganic chemical vapor deposited (Ba,Sr)RuO3 interfacial layers

The conducting oxide (Ba,Sr)RuO3 (BSR), which offers an appropriate match i n structure with (Ba,Sr)TiO3 (BST), was investigated as an interfacial laye r to obtain a high tunability and high dielectric constant in BST films. Th e (100)-textured BST films deposited onto BSR interfacial layers showed smo other smaller grain size than those without BSR layers. The tunability and dielectric constant of the BST films increased with increasing BSR seed lay er thickness and showed similar to 70% tunability and a dielectric constant of 1300 at interfacial layer of 150 Angstrom. The tunability and dielectri c constant of BST films increased nearly two times and two and a half times , respectively, as much as that of BST films without BSR interfacial layers . The higher tunability and dielectric constant have been attributed to the suppression of low-dielectric layer formation and the reduced thermal stre ss by lattice mismatch. (C) 2001 American Institute of Physics.