Ultralow Temperature Processing and Integration of Dielectric Resonators on Silicon Substrates for System-on-Chip Applications

Ultralow temperature processing of Ba
₂
Ti
₉
O
₂₀
thin-film ceramics and the attachment of a porous dielectric resonator cylinder on a conducting prepatterned silicon substrate have been accomplished using a hydrothermal process at 150degC/3 h. Enhanced densification and mechanical strength at the bulk ceramic-thin-film interface were induced by a dissolution-crystallization process involving a sol-gel solution under 13-15 atm pressure. Recrystallization forms electrical bridges between powder particles to form an interconnected microstructure, which eliminates grain boundary defects and, hence, improves the dielectric properties. This method has potential for growth of dielectric resonators on integrated circuits for system-on-chip applications and is implemented for the fabrication of an integrated dielectric resonator antenna.