Title :
Structural and dielectric characterization of SrTio3 and BST thin films for microwave applications
Author :
Bellotti, J. ; Akdogan, E.K. ; Safari, A.
Author_Institution :
Dept. of Ceramics & Mater. Eng., Rutgers Univ., Piscataway, NJ, USA
Abstract :
Heteroepitaxial SrTiO3 and polycrystalline Ba(1-x) SrxTiO3 (x = 0.35, 0.40, 0.50) thin films (~300 nm) were deposited on (100) oriented LaAlO3 single crystal substrates by pulsed laser deposition using a KrF excimer laser (λ = 248 nm). RBS, XRD, FESEK and AFM were used for structural characterization. The stoichiometry was found to be closest to ideal at higher temperatures around 750°C. The SrTiO3 films were confirmed to be epitaxial with XRD omega scans, while the BST films were polycrystalline. The permittivity and loss tangent of the films were measured in the range of 1 kHz to 1 MHz. Both materials showed a high dielectric constant 230 for ST and around 800 for BST at room temperature, with losses on the order of a few percent. The tunability of BST was also measured and found to be up to 35%, depending on composition. In addition, correlations between film morphology, processing conditions, and stoichiometry are discussed
Keywords :
Rutherford backscattering; X-ray diffraction; atomic force microscopy; barium compounds; dielectric losses; dielectric thin films; microwave devices; permittivity; pulsed laser deposition; scanning electron microscopy; strontium compounds; 1 kHz to 1 MHz; 248 nm; 300 nm; 750 degC; AFM; Ba(1-x)SrxTiO3; FESEM; RBS; SrTiO3; XRD; dielectric constant; dielectric thin films; film morphology; heteroepitaxial thin films; loss tangent; microwave dielectric devices; permittivity; polycrystalline thin films; processing conditions; pulsed laser deposition; structural characterization; tunability; Binary search trees; Dielectric loss measurement; Dielectric measurements; Dielectric thin films; Pulsed laser deposition; Sputtering; Strontium; Substrates; Temperature; X-ray scattering;
Conference_Titel :
Applications of Ferroelectrics, 2000. ISAF 2000. Proceedings of the 2000 12th IEEE International Symposium on
Conference_Location :
Honolulu, HI
Print_ISBN :
0-7803-5940-2
DOI :
10.1109/ISAF.2000.942455
