Tunable Dielectric Properties of BST Thin Films for RF/MW Passive Components

Autor: Steven W. Kirchoefer, Ahmad Safari, Jeffrey A. Bellotti, E. Koray Akdogan, Wontae Chang
Rok vydání: 2002
Předmět:
Zdroj: Integrated Ferroelectrics. 49:113-122
ISSN: 1607-8489
1058-4587
DOI: 10.1080/713718340
Popis: Heteroepitaxial Ba 0.6 Sr 0.4 TiO 3 films were deposited on (100) LaAlO 3 and (100) MgO substrates via pulsed laser deposition. Film thickness varied from 22 nm to 1.15 w m. All films were examined with x-ray diffraction and cross-section FESEM to determine both epitaxy and thickness, and stoichiometry was confirmed with RBS measurements. Microwave dielectric measurements were carried out in the range of 1-20 GHz, using an interdigitated electrode array. The state of strain in the films as a function of thickness and substrate type was correlated with the observed capacitive tunability. The tunability for both film series was shown to exhibit markedly different behavior depending on the type of strain, compressive or tensile. Maximum dielectric tunabilities of ∼ 65% were achieved for the thickest films in both film sets, however the tunability of the thinnest films were much higher for the films grown on MgO.
Databáze: OpenAIRE