Low-Temperature Synthesis and Growth of Bulk Ba2Ti9O20 Ceramics on Conducting Substrates for Applications in Integrated Dielectric Resonator Devices
Abstract:This paper describes the synthesis of Ba2Ti9O20 ceramics at extremely low temperatures (∼150°C) and the subsequent growth of bulk resonators on silicon substrates by hydrothermal processing of their sol–gel composites. X-ray diffraction analysis shows excellent crystallinity, while scanning electron microscopy evidenced densification and development of bridging structures at the grain boundaries and interfaces. Transmission electron micrographs further confirmed the development of sol–gel-derived crystalline interfaces between sol–gel-derived material and powder particles. The dielectric properties of a resonator measured in the 5–6 GHz microwave frequency range were r=38 and Qu×f=12,000 at 5.6 GHz and f=+6 ppm/°C. The density, dielectric properties, and mechanical strength at the bulk ceramic–thin film interface are enhanced by a hydrothermally induced dissolution–crystallization process, which leads to interparticle bridges. The novel low-temperature ceramic process has high potential for the growth of ceramic resonators on integrated circuits and is demonstrated by the fabrication of an integrated dielectric resonator antenna for system-on-chip applications.
Document Type: Research Article
Affiliations: 1: Department of Electrical and Computer Engineering, Royal Military College of Canada, Kingston, ON, Canada K7K 7B4 2: Department of Electrical and Computer Engineering, Queen's University, Kingston, ON, Canada K7L 3N6 3: Department of Physics, Queen's University, Kingston, ON, Canada K7L 5C4
Publication date: 2008-07-01