High Tunable BaTi_xZr_1-xO₃ Films on Dielectric Substrate for Microwave Applications

Abstract

In this study, the structural and microwave properties of BaTiZrO3 films deposited on alumina substrate were investigated. The films were deposited by RF magnetron sputtering in Ar/O2 ambient atmosphere. The research of the island films at the initial stages of the growth showed that the pyramidal type of growth prevails. It was demonstrated that as-deposited film is a BaZrTiO3 solid solution with a deficiency of titanium compared to the target. The air annealing at temperatures of 1100–1200 °C leads to the formation of a well-formed crystalline solid solution of BaZr0.3Ti0.7O3 with a predominant orientation (h00). The investigation of microwave parameters of the films fabricated at different conditions showed that the best performance with the tunability of 4.6 (78%), and the Q-factor of 18 to 40 at 2 GHz was achieved at annealing temperature of 1150 °C.

Keywords

• barium titanate–zirconate
• rf magnetron sputtering
• initial stages of growth
• microwave properties